To see the other types of publications on this topic, follow the link: Shoot tip reduction.
Journal articles on the topic 'Shoot tip reduction'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Shoot tip reduction.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Remphrey, W. R., and C. G. Davidson. "Branch architecture and its relation to shoot-tip abortion in mature Fraxinus pennsylvanica." Canadian Journal of Botany 70, no. 6 (1992): 1147–53. http://dx.doi.org/10.1139/b92-142.
Full textAbstract:
The architecture of branch complexes, 10 to 14 years old, from mature male and female green ash trees (Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern.) of two crown shapes was analyzed. Shoot length (annual increment of extension growth) declined with increasing order of branching and 47% of the shoots were less than 30 mm. Although variable, shoot length also tended to decrease along an axis. There was a consistent positive correlation between lengths and numbers of daughter shoots and lengths of parent shoots, but for a given parent length the predicted values declined proportionately with increasing order. An index of apical control comparing the lengths of terminal shoots with the longest lateral shoots revealed weaker apical control with increasing branch order in the broad, rounded crown shape class compared with the narrow shape class. Elevation angles of terminal daughter shoots were highly correlated with that of the parent shoot. When a shoot tip aborted, the terminal was replaced, but a weakening of apical control resulted in the modification of branch development and the formation of forks in certain axes. There was a reduction in the angle of divergence of lateral shoots in response to shoot-tip abortion, the terminal replacements being the most acute. Key words: crown architecture, shoot-tip abortion, green ash, Fraxinus, tree form, branching pattern.
2
Aguinaz, Hayat, Ahmed Qaddoury, and Mohamed Anjarne. "Control of in vitro shoot tip necrosis in Carob Ceratonia siliqua L." Israel Journal of Plant Sciences 67, no. 3-4 (2020): 212–18. http://dx.doi.org/10.1163/22238980-20201046.
Full textAbstract:
Shoot tip necrosis (STN) is a physiological abnormality whereby the apical shoot initially becomes necrotic and subsequently dies leading to considerable loss of shoots and hampering any commercial application of carob (Ceratonia siliqua L.) micropropagation. The objective of the present study is the optimization of a method to alleviate STN during in vitro multiplication of carob dealing with a range of culture media compounds. Obtained results showed that macroelement strength of the culture medium as well as cytokinin and calcium concentrations were the most important factors in controlling STN incidence in carob. In fact, Zimmerman macroelements are most efficient in terms of STN reduction (only 5% STN observed) and shoot multiplication (28.75 shoots with 26.8 leaves and 4.73 cm length). Moreover, shoots cultured on Zimmerman or Ca enriched ½MS showed higher mineral nutrient contents than those cultured on low Ca media. On the other hand, most shoots recovered from STN have produced roots in presence of 1 mg.L-1 IAA (70%) and 83% survived after transfer to ex vitro conditions. The performance of Zimmerman macroelements is most likely due to its high Ca concentration (7.3 mM) compared to the other media. This is confirmed by the steep reduction of STN intensity obtained on ½MS enriched with Ca.
3
Dahniya, M. T., S. K. Hahn, and C. O. Oputa. "Effect of Shoot Removal on Shoot and Root Yields of Sweet Potato." Experimental Agriculture 21, no. 2 (1985): 183–86. http://dx.doi.org/10.1017/s0014479700012461.
Full textAbstract:
SUMMARYExperiments on harvesting sweet potato as a green vegetable and as a root crop are described. Whole shoots yielded 62% more than shoot tips. Similar total shoot yields were harvested whether tip removal was at two, three or four week intervals. Root yield was decreased by 31 to 48% by removing shoot tips, while removing whole shoots led to root yield decreases of 48 to 62%. Harvesting shoots at two week intervals gave 72% reduction in root yield, compared with 50% with four week intervals. There were fewer and smaller tubers as the frequency of shoot harvests increased. There were varietal differences in response to shoot removal For reasonable yields of both shoot tips and tuberous roots harvesting shoot tips at four week intervals is recommended.
4
Pancaningtyas, Sulistyani. "Effectiveness of calcium chloride in reduction of shoot necrosis incocoa (Theobroma cacao L.) in vitro propagation." Pelita Perkebunan (a Coffee and Cocoa Research Journal) 28, no. 1 (2012): 23–31. http://dx.doi.org/10.22302/iccri.jur.pelitaperkebunan.v28i1.161.
Full textAbstract:
Various efforts have been developed for the optimization of the various stages in vitro micropropagation. The maturation stage and pre-acclimatization plantlets is an important stages that must be considered to produce vigorous plants and ready to be planted in the field. The purpose of this study was to reduced shoot tip necrosis in cocoa planlets to obtaine vigorous planlets from in vitro propagation through the addition of Calcium Chloride (CaCl2). The study used two stages of embryogenic development. The first was embryo maturation stage and the second was the shoot growth development stage. The study was arranged factorially in experiment design of Completely Randomized Design consisting of two factors i.e. concentration of CaCl2 consisted of 0, 50, 100, 150, and 200 mg/l and clones consisted of Sulawesi 1 and Sca 6. Each experiment was repeated three times, so the number of combination trials were 5x2x3=30 experimental units. The parameters observed included shoot growth percentage and vigorous planlets percentage. The results showed that the addition of CaCl2 at a concentration of 150 mg/l during maturition stage increased the embryos performance and percentage of shoot tip. However, it could not prevent the shoot tip necrosis. Whereas, the addition at a concentration of 50 mg/l during the shoot m growth development stage could reduced necrosis, suggested to increase the quality of in vitro planlets.Key words: Cocoa, necrosis, calcium chloride, somatic embryogenesis, embryos, planlets, in vitro.
5
Driessche, R. Van Den, and D. Ponsford. "Nitrogen induced potassium deficiency in white spruce (Piceaglauca) and Engelmann spruce (Piceaengelmannii) seedlings." Canadian Journal of Forest Research 25, no. 9 (1995): 1445–54. http://dx.doi.org/10.1139/x95-157.
Full textAbstract:
White spruce (Piceaglauca (Moench) Voss) and Engelmann spruce (Piceaengelmannii Parry ex Engelm.) seedlings grown for 2 or more years in sandy loam nursery soils in British Columbia often show yellow and necrotic shoot-tip symptoms. Chemical analysis of a white spruce and a white × Engelmann hybrid spruce provenance showed that the symptoms were associated with low needle K concentrations. After nursery growth was complete, growth tests showed that seedlings with symptoms took longer to flush and had 43% less shoot extension than normal green seedlings. To see why K fertilizer alone did not always cure the symptoms, 1.5-year-old Engelmann spruce seedlings were transplanted and grown for a further 1.5 years in a 4 × 3 × 3 factorial experiment (K level × N source × N level). Nitrogen fertilization increased growth and symptom occurrence, with sources resulting in more symptoms in the order (NH4)2SO4 < NH4NO3 < Ca(NO3)2. Potassium fertilization decreased symptoms, although not completely, but had no effect on growth. Shoot-tip NH4+ was positively correlated with symptoms, while higher levels of soil and shoot-tip K, as well as soil and shoot-tip Mg, were associated with reduction in symptoms. It was concluded that heavy N fertilization created requirements for K, and probably Mg, above the tissue concentrations normally regarded as adequate, and that K fertilization did not always eliminate symptoms because of a Mg requirement.
6
Mohammad Javad, Mahmoudi Meimand, Malekzade Khalil, Hossein Shamshiri Mohammad, Reza Dehghani Mohammad, and Dadaei Somayeh. "ROLE OF VENTILATION, CALCIUM AND BORON ON SHOOT TIP NECROSIS AND HYPERHYDRICITY REDUCTION OF IN VITRO ROORSTOOCKS OF PISTACIO ‘BADAMI’ ȘI ‘UCB1’." Fruit Growing Research 37, no. 37 (2021): 123–30. http://dx.doi.org/10.33045/fgr.v37.2021.17.
Full textAbstract:
Shoot tip necrosis (STN) is one of the main physiological disorders in the micropropagation of pistachios. In the current study, the effects of CaNO3.4H2O at 196 mg/L and 291 mg/L, H3BO3 at 196 mg/L and 291 mg/L, and CaCl2.2H2O at 2,980 mg/L on STN and hyperhydricity reduction of Pistacia vera L., ‘Badami’ and ‘UCB1’ rootstocks were assessed, compared to the MS standard medium containing 3% sucrose, 0.7% agar supplemented with benzyladenine (BA) (1.5 mg/L), indole butyric acid (IBA) (0.1 mg/L). For ventilation parameter, filter container vessels with a 50-µm microporous polypropylene membrane (Pardis®) were used. Based on the results, an increase in calcium chloride content of the MS standard medium prevented hyperhydricity in the UCB1 rootstock, whereas it increased STN, yellow leaves, decreasing the multiplication of shoots in the ‘Badami’ rootstock. The results also showed that increasing boric acid from 196 mg/L up to 291 mg/L decreased STN in the UCB1 rootstock and increased this disorder by 37% in the ‘Badami’ rootstock. Ventilation showed no significantly reducing effect on the percentage of STN in the regenerated shoots of the ‘Badami’ rootstock, whilst it decreased the STN of the ‘UCB1’ rootstock to the lowest percentage. For the ‘Badami’ rootstock, CaNO3.4H2O at 196 mg/L led to the highest proliferation rate, shoot height, shoot diameter, and leaf number, but for the ‘UCB1’ rootstock, an increase in the concentration of CaNO3.4H2O up to 291 mg/L under ventilated conditions resulted in an increase in proliferation, shoot height, and shoot diameter.
7
Snir, Iona. "Influence of Paclobutrazol on in Vitro Growth of Sweet Cherry Shoots." HortScience 23, no. 2 (1988): 304–5. http://dx.doi.org/10.21273/hortsci.23.2.304.
Full textAbstract:
Abstract Shoot tips from in vitro-established shoot tip cultures of Prunus avium L. cv. Hedelfingen and cv. Starkrimson were cultured on sweet cherry propagation medium to which several concentrations of paclobutrazol (PP333) were added and gibberellic acid (GA3) omitted, in order to reduce the elongation of the shoots. A reduction in both shoot length and bud number was achieved even with the lowest concentration of paclobutrazol (0.2 mg·liter–1). Shoot tips from the inhibited cultures when replanted on regular propagation medium overcame the inhibition at the first transfer. In order to use this system for cold preservation experiments, the cultures were examined under dark and low temperature conditions (0.5° ± 0.5°C). There was a significant difference between the PP333 system and the control after certain periods of cold preservation. The survival ratio of the PP333-inhibited culture was higher than the control after removing from the cold preservation conditions and recultured. Chemical name used: β-[(4- chlorophenyl)methyl]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol.
8
Remphrey, William R., Grant A. Bartlett, and Campbell G. Davidson. "Shoot morphology and fate of buds in relation to crown location in young Fraxinus pennsylvanica var. subintegerrima." Canadian Journal of Botany 80, no. 12 (2002): 1274–82. http://dx.doi.org/10.1139/b02-120.
Full textAbstract:
The relationships between shoot size and morphological patterns and crown location were investigated in 6-year-old green ash (Fraxinus pennsylvanica var. subintegerrima (Vahl) Fern.). In general, shoots were shorter in the inner part of the crown compared with either the top or bottom near the periphery. The differences were related to a reduction in both metamer number and length. In some cases the lower crown location was similar to the upper; in other cases it was similar to the inside. The fate of buds along a shoot was generally dependent on shoot position in the crown. A greater proportion of buds became lateral shoots and inflorescences in the top compared with the bottom of the crown, and the fewest developed towards the inside location. As the number of metamers per shoot increased, there was an increase in the proportion of lateral shoots produced and a decrease in the proportion of inflorescences and (or) aborted buds. For shoots with the same number of metamers per shoot, those in the top produced a greater proportion of inflorescences and lateral shoots compared with the bottom or inside. In all crown locations, the highest number of buds aborted near the base, the greatest proportion of inflorescences occurred in mid-shoot regions, and the largest proportion of lateral shoots occurred near the tip. The information presented in this paper will be used as a component in developing a simulation model of crown development.Key words: architecture, shoot, bud fate, green ash, metamer.
9
Yang, Yuehua, Fangkui Wang, Jialin Jiang, and Ling Jiang. "Inhibition of Citrus Huanglongbing Disease by Paenibacillus polymyx KN-03 and Analysis with Transcriptome and Microflora." Agronomy 13, no. 12 (2023): 2958. http://dx.doi.org/10.3390/agronomy13122958.
Full textAbstract:
Soil drench treatment using Paenibacillus polymyxa strain KN-03 was applied to citrus plants infected with Candidatus Liberibacter asiaticus (CLas). The infection status was assessed using PCR and a real-time quantitative PCR detection system (qPCR). The application of KN-03 resulted in a notable reduction in CLas levels in citrus plants. Specifically, by the 257th day post treatment commencement, following 24 KN-03 applications, the negative rates of CLas in the vein, root tip, and shoot tip were 50%, 0%, and 50%, respectively. After 24 cycles, KN-03 application significantly enhanced plant growth and stimulated reactive oxygen production in citrus leaves compared to control plants. Transcriptome analysis identified specific upregulated pathways. Furthermore, flora analysis revealed an increased abundance of microorganisms possessing potential utilization value, including Burkholderia-Caballeronia-Paraburkholderia, uncultured_bacterium_o_Acidobacteriales, uncultured_bacterium_f_Gemmatimonadaceae, and Rhodanobacter, in the root zone. Moreover, the BugBase analysis indicated that KN-03 treatment increased the abundance of beneficial rhizosphere bacteria associated with biofilm formation, element mobilization, and stress tolerance. These findings support the utility of Paenibacillus polymyxa KN-03 as an effective plant-growth-promoting bacterium for CLas management, with additional benefits for plant growth and soil health, specifically offering detoxification resources for shoot tip grafting.
10
HICKLENTON, PETER R. "HEIGHT CONTROL OF POT CHRYSANTHEMUMS WITH PRE- AND POST-PLANT TREATMENTS OF DAMINOZIDE AND UNICONAZOLE." Canadian Journal of Plant Science 70, no. 3 (1990): 925–30. http://dx.doi.org/10.4141/cjps90-113.
Full textAbstract:
This study investigated the effects of growth retardants uniconazole [(E) - (p-chlorohenyl) -4, 4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol] and daminozide (butanedioic acid mono 2,2-dimethylhydrazide) on three chrysanthemum (Dendranthema grandiflora Tzvelev.) cultivars. Uniconazole applied as a soil drench (0.02 mg a.i. pot−1) or foliar spray (0.014 mg a.i. pot−1) 10 d after removal of the shoot tip reduced plant height at harvest in cultivars Deep Luv, Tip and Tara. Higher doses of uniconazole resulted in further plant height reduction in Tip and Tara but not in Deep Luv. Daminozide spray (14 mg a.i. pot) and uniconazole spray (0.028 or 0.056 mg a.i. pot−1) produced plants of similar height. Pre-plant dips of both growth retardants were less effective than sprays or drenches in controlling height. Flower area and flower dry weight were reduced with uniconazole drench and spray, and daminozide spray in each cultivar. Shoot dry weight was similarly affected in Tip and Tara but not in Deep Luv. Flowering was delayed in each cultivar by post-plant treatments of uniconazole drench and spray and by daminozide spray (0.08, 0.014 and 14 mg a.i. pot−1, respectively), and by daminozide and uniconazole pre-plant dips (5.0 mg L−1 and 4000 mg L−1, respectively).Key words: Sumagic, XE-1019, B-Nine, Alar, Chrysanthemum × morifolium, Dendanthema grandiflora
11
Faust, James E., Sven Verlinden, and Royal D. Heins. "779 PB 395 PULSING TEMPERATURES AND SYRINGING AT SUNRISE REDUCE STEM ELONGATION OF EASTER LILY." HortScience 29, no. 5 (1994): 544e—544. http://dx.doi.org/10.21273/hortsci.29.5.544e.
Full textAbstract:
Rapid reduction in temperature for two to three hours starting at sunrise reduces stem elongation compared to elongation of plants maintained under constant temperatures during the day. This experiment was designed to determine if syringing plants with water at sunrise would substitute for a reduction in air temperature or enhance the response to the drop in temperature. Easter lily (Lilium longiflorum Thumb.) plants were exposed to constant 20°C or to 20°C and then 16°C for a 3-hr period following sunrise. Half the plants in each temperature regime were syringed at 30-minute intervals with 20°C water for 3 hr starting 20 minutes before sunrise. Shoot-tip temperature during the three-hr pulse time averaged 20.0 and 17.3°C for the dry plants and 17.3 and 14.7°C for the syringed plants. Total elongation for the dry plants at 20°C was 30 cm and for the temperature-pulsed plants, 4.8 cm less; for the syringed plants, 3.3 and 5.8 cm less, respectively. While shoot-tip temperature of dry plants averaged 0.9°C above air temperature during the remaining hours of the day, syringed plants averaged 1.0°C cooler than the same air temperature even though plants had dried. The data indicate the reduction in stem elongation from a low-temperature pulse at sunrise can be enhanced by evaporative cooling.
12
Blomme, Guy, Hilde de Beule, Rony Swennen, Abdou Tenkouano, and Dirk De Waele. "Effect of nematodes on root and shoot growth of in vitro-propagated and sword sucker-derived plants of six Musa spp. genotypes." Nematology 6, no. 4 (2004): 593–604. http://dx.doi.org/10.1163/1568541042665197.
Full textAbstract:
Abstract This study evaluated the effect of infection by a mixture of nematode species (including Helicotylenchus multicinctus, H. dihystera, Hoplolaimus pararobustus, Meloidogyne spp. and Radopholus similis) on the root system size and shoot growth of six Musa genotypes. In addition, the influence of type of planting material on susceptibility and sensitivity to nematodes was assessed, comparing suckers (i.e., lateral shoots) and in vitro-derived planting material, produced through shoot-tip culture techniques. The Musa genotypes were the triploid (AAA-group) dessert banana cvs Yangambi km5 and Gros Michel, the triploid plantain cvs Agbagba and Obino l'Ewai (both AAB-group) and two IITA improved tetraploid plantain hybrids TMPx 548-9 and TMPx 5511-2. The study was carried out at the International Institute of Tropical Agriculture High Rainfall station at Onne in southeastern Nigeria in an ultisol soil. During vegetative growth, shoot growth of infected plants was less than that of non-infected plants. At flower emergence, a severe reduction in root system size (as much as 75%) was associated with moderate (in most cases less then 20%) reduction in corm and shoot growth characteristics. This indicates that Musa spp. plants grow relatively well with a reduced root system, i.e., the remaining root system can supply the plant with the necessary nutrients and water. Root systems of sucker-derived dessert bananas tolerated higher nematode population densities than those of in vitro-derived plants. Plantains were highly sensitive as moderate nematode population densities caused a severe reduction in root system size.
13
Faruk, Md Iqbal. "Effect of Soil and Foliar Application of Plant Nutrients on Purple Blotch and Tip-Burn of Garlic." Journal of Agronomy Research 4, no. 3 (2022): 39–49. http://dx.doi.org/10.14302/issn.2639-3166.jar-22-4114.
Full textAbstract:
An experiment was conducted in the field of Plant Pathology Division, BARI, Joydebpur to evaluate the efficacy of available plant nutrient for the development of purple blotch disease and tip-burn of onion. Eight different treatments viz. Potassium (MP fertilizer), Phosphorus (TSP fertilizer), Boron (Boron fertilizer), Zinc (ZnSO4 fertilizer), Calcium (CaSO4 fertilizer), Copper (CuSO4), Silicon (silica gel) and Manganese (MnSO4 fertilizer) were tested against purple blotch disease and tip-burn of garlic. The present study revealed that soil and foliar application of plant nutrients viz. Potassium, Phosphorus, Boron, Zinc, Calcium, Copper, Silicon and Manganese gave appreciable reduction of purple blotch disease and tip-burn incidence and increased plant growth parameters such as shoot and root growth as well as yield of garlic. Among the nutrients Potassium, Phosphorus, Silicon, Zinc and Calcium were performed better for reducing purple blotch disease severity, tip-burn disease incidence and increasing plant growth as well as yield of garlic. Application of Boron and Manganese also performed better than control. So, soil and foliar application plant nutrients Potassium, Phosphorus, Silicon, Zinc, Boron and Manganese may be recommended for tip-burn and purple blotch disease management and for garlic production in Bangladesh.
14
Davies, W. J., J. Metcalfe, T. A. Lodge, and A. R. da Costa. "Plant Growth Substances and the Regulation of Growth Under Drought." Functional Plant Biology 13, no. 1 (1986): 105. http://dx.doi.org/10.1071/pp9860105.
Full textAbstract:
This paper reviews briefly the effects of water deficits on the synthesis and distribution of plant growth regulators with some emphasis on genotypic variation in synthesis. The effects of abscisic acid on growth and development are also considered and interactions between growth regulators are highlighted. One possible role for a growth regulator in providing a mechanism to regulate physiology, growth and development as a function of water availability is discussed in detail. It is proposed that reduction in root tip turgor will reduce the synthesis and transport of cytokinins in the root tip and that this reduced transport, perhaps combined with drought-induced reduced uptake of nutrients from the soil, will influence the physiology of the shoot independently from any hydraulic influence.
15
McClay, A. S. "EFFECTS OF BRACHYPTEROLUS PULICARIUS (L.) (COLEOPTERA: NITIDULIDAE) ON FLOWERING AND SEED PRODUCTION OF COMMON TOADFLAX." Canadian Entomologist 124, no. 4 (1992): 631–36. http://dx.doi.org/10.4039/ent124631-4.
Full textAbstract:
AbstractImpact of the flower- and shoot-tip-feeding beetle, Brachypterolus pulicarius (L.), on growth, flowering, and seed production of common toadflax, Linaria vulgaris (L.) Mill., was investigated using potted plants. Brachypterolus pulicarius had no effect on root or shoot biomass of attacked plants. Adult feeding by B. pulicarius delayed onset of flowering by 27 days relative to controls. Flowering of attacked plants was suppressed from mid-June until mid-July, but by mid-August flowering was similar to that of control plants. Total seed weight, individual seed weight, and percentage germination were all reduced significantly on attacked plants, resulting in a 74% reduction in number of viable seeds produced. Brachypterolus pulicarius is univoltine in Alberta, overwintering mainly as pupae.
16
Yarmus, Itay, Dana Gelbart, Einat Shemesh-Mayer, et al. "Pathogen Eradication in Garlic in the Phytobiome Context: Should We Aim for Complete Cleaning?" Plants 12, no. 24 (2023): 4125. http://dx.doi.org/10.3390/plants12244125.
Full textAbstract:
Global food production is challenged by plant pathogens that cause significant crop losses. Fungi, bacteria, and viruses have long threatened sustainable and profitable agriculture. The danger is even higher in vegetatively propagated horticultural crops, such as garlic. Currently, quarantine, rouging infected plants, and control of natural vectors are used as the main means of disease and pest control in garlic crops. Agricultural biotechnology, meristem-tip culture, and cryotherapy offer solutions for virus eradication and for the multiplication of ‘clean stocks’, but at the same time, impact the symbiotic and beneficial components of the garlic microbiome. Our research involves the first metatranscriptomic analysis of the microbiome of garlic bulb tissue, PCR analyses, and a biological assay of endophytes and pathogens. We have demonstrated that in vitro sanitation methods, such as shoot tip culture or cryotherapy can alter the garlic microbiome. Shoot tip culture proved ineffective in virus elimination, but reduced bacterial load and eliminated fungal infections. Conversely, cryotherapy was efficient in virus eradication but demolished other components of the garlic microbiome. Garlic plants sanitized by cryotherapy exhibited a lower survival rate, and a longer in vitro regeneration period. The question arises whether total eradication of viruses, at the expense of other microflora, is necessary, or if a partial reduction in the pathogenic load would suffice for sanitized garlic production. We explore this question from both scientific and commercial perspectives.
17
Faruk, MI. "Effect of Soil and Foliar Application of Plant Nutrients on Purple Blotch and Tip-Burn of Onion." Bangladesh Journal of Agricultural Research 46, no. 2 (2023): 153–65. http://dx.doi.org/10.3329/bjar.v46i2.64119.
Full textAbstract:
An experiment was conducted in the field of Plant Pathology Division, BARI, Cazipur, during Robi 2015-16, 2016-17 and 2017-18 cropping seasons to evaluate the efficacy of available plant nutrients against purple blotch disease and tip-burn of onion. Eight different plant nutrients viz. Potassium (ZnSO4 fertilizer), Phosphorus (TSP fertilizer), Boron (Boron fertilizer), Zinc (ZnSO4 fertilizer), Calcium (CaSO4 fertilizer), Copper (CuSO4), Silicon (silica gel) and Manganese (MnSO4 fertilizer) were tested against purple blotch disease and tip-burn of onion. Soil and foliar application of plant nutrients viz. Potassium, Phosphorus, Boron, Zinc, Calcium, Copper, Silicon and Manganese in the formed of water solution gave appreciable reduction of purple blotch disease and tip-burn incidence and increased plant growth such as shoot and root growth as well as yield of onion. Among the nutrients solution Potassium, Phosphorus, Silicon, Zinc and Calcium were performed better for reducing purple blotch disease severity (upto 62.78%), tip-burn incidence (upto 72.22%) and increasing plant growth as well as yield of onion. Application of Boron and Manganese also performed better than control. So, soil and foliar application plant nutrients viz. Potassium, Phosphorus, Silicon, Zinc, Boron and Manganese might be recommended for tip-burn and purple blotch disease management and also for onion production in Bangladesh. Bangladesh J. Agril. Res. 46(2): 153-165, June 2021
18
Wang, Yin-Tung, and Lori L. Gregg. "Uniconazole Affects Vegetative Growth, Flowering, and Stem Anatomy of Hibiscus." Journal of the American Society for Horticultural Science 114, no. 6 (1989): 927–32. http://dx.doi.org/10.21273/jashs.114.6.927.
Full textAbstract:
Abstract Eight-month-old ‘Jane Cowl’ hibiscus (Hibiscus rosa-sinensis L.) in 2.8-liter pots received 0, 0.1, 0.2, or 0.4 mg of uniconazole/pot as a soil drench. Plants were pruned 35 days after treatment and then grown for an additional 65 days. Plant height, number of leaves and flower buds per shoot, shoot length, stem diameter, and leaf size decreased with increasing rates of uniconazole. Flower number was greater at the two low rates; however, days to first bloom and leaf dark respiration rate were unaffected. Leaf chlorophyll concentration increased with increasing rates of uniconazole. Development of secondary xylem tissue, transverse diameter of vessels, and number and size of phloem fibers were suppressed by uniconazole, resulting in a cascading growth habit. Plants grown from cuttings taken from plants 35 days after treatment were shorter, with fewer lateral shoots and total leaves than cuttings from untreated plants. Uniconazole had no effect on growth of shoot tip cuttings taken from the new lateral shoots of treated plants 110 days after pruning. Soil drenches of uniconazole at 0.025 to 0.2 mg/pot to young plants in 1.5-liter pots resulted in shorter plants, delayed flowering, and fewer flowers with smaller diameter and shorter pedicels. Results from foliar application of uniconazole at 0.05 to 0.2 mg/plant (10 to 40 mg·liter−1) were similar to the soil drench, except that the reduction in shoot growth was less at low rates than with drench application. Chemical name used: (E)-1-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (uniconazole).
19
Haq, Izharul, Vineeta Kumari, Sharad Kumar, Abhay Raj, Mohtashim Lohani, and Ram Naresh Bhargava. "Evaluation of the Phytotoxic and Genotoxic Potential of Pulp and Paper Mill Effluent Using Vigna radiata and Allium cepa." Advances in Biology 2016 (August 29, 2016): 1–10. http://dx.doi.org/10.1155/2016/8065736.
Full textAbstract:
Pulp and paper mill effluent induced phytotoxicity and genotoxicity in mung bean (Vigna radiata L.) and root tip cells of onion (Allium cepa L.) were investigated. Physicochemical characteristics such as electrical conductivity (EC), biological oxygen demand (BOD5), chemical oxygen demand (COD), and total phenols of the pulp and paper mill effluent were beyond the permissible limit specified for the discharge of effluent in inland water bodies. Compared to control plants, seedling exposed to 100% effluent concentration showed a reduction in root and shoot length and biomass by 65%, 67%, and 84%, respectively, after 5 days of treatment. A. cepa root tip cells exposed to effluent concentrations ranging from 25 to 100% v/v showed a significant decrease in mitotic index (MI) from 32 to 11% with respect to control root tip cells (69%) indicating effluent induced cytotoxicity. Further, the effluent induced DNA damage as evidenced by the presence of various chromosomal aberrations like stickiness, chromosome loss, anaphase bridge, c-mitosis, tripolar anaphase, vagrant chromosome, and telophase bridge and micronucleated and binucleated cell in A. cepa. Findings of the present study indicate that pulp and paper mill effluents may act as genotoxic and phytotoxic agents in plant model system.
20
Batish, Daizy R., Harminder Pal Singh, Ravinder K. Kohli, Shalinder Kaur, Dinesh B. Saxena, and Surender Yadav. "Assessment of Phytotoxicity of Parthenin." Zeitschrift für Naturforschung C 62, no. 5-6 (2007): 367–72. http://dx.doi.org/10.1515/znc-2007-5-609.
Full textAbstract:
Phytotoxicity of parthenin, a sesquiterpene lactone, was evaluated against four weedy species (Amaranthus viridis, Cassia occidentalis, Echinochloa crus-galli, and Phalaris minor) through a series of experiments conducted under laboratory or greenhouse conditions to assess its herbicidal potential. Under laboratory conditions, parthenin (0.5 - 2 mm) severely reduced seedling growth (root and shoot) and dry weight of test weeds. However, the effect was greater on root growth. Parthenin (1 mm) suppressed the mitotic activity in the onion root tip cells that could possibly be responsible for the reduction in seedling growth. Both pre- and post-emergent application of parthenin caused a significant loss of chlorophyll pigments and affected photosynthesis. Parthenin (≥1 mm) caused an excessive electrolyte leakage in the plant tissues which was light-dependent. The root inhibition was associated with swelling and blackening of the root tip, shriveling and damage to the epidermal tissue and non-formation of root hairs. The study concludes that parthenin possesses weed-suppressing potential (both pre- and post-).
21
Robinson, Terence L., and Bruce H. Barritt. "Endogenous Abscisic Acid Concentrations, Vegetative Growth, and Water Relations of Apple Seedlings following PEG-induced Water Stress." Journal of the American Society for Horticultural Science 115, no. 6 (1990): 991–99. http://dx.doi.org/10.21273/jashs.115.6.991.
Full textAbstract:
In unstressed apple seedlings (Malus domestics Borkh.), concentrations of free abscisic acid (ABA) decreased in order from apical stem sections, immature expanding leaves, mature stem sections, and mature leaves. PEG-induced water stress stimulated a 2- to 10-fold increase in free ABA concentrations 1 day after treatment, depending on the amount of stress and the tissue. By the 3rd day of stress, free ABA concentrations were nearly the same as the unstressed treatment and remained low for the remainder of the 21-day stress period. Bound ABA concentrations were an order of magnitude lower than free ABA and were not influenced dramatically by water stress. Shoot growth rate, leaf expansion rate, and leaf emergence rate were reduced by water stress in relation to the severity of the stress; this reduction was associated with the initial increase in ABA. However, there was no increase in shoot or leaf growth rates associated with the decline in ABA concentrations by day 3 as growth rates remained depressed on water-stressed plants throughout the 21-day stress period. Water stress reduced evapotranspiration rate and midshoot leaf water potential (ψW)after 1 day, but leaf osmotic potential (ψS) adjusted more slowly, resulting in a loss of leaf turgor. The reduction in leaf turgor pressure (ψP) was highly correlated with decreased shoot growth rate and increased ABA concentrations on day 1 after treatment. By the 3rd day of water stress, ψP bad recovered even in the most severe treatment, and the recovery of turgor was associated with the drop in ABA concentrations. However, the increase in midshoot ψP and the decline in ABA were not associated with any increase in shoot growth rate. The continued inhibition of shoot growth was probably not related to ABA or turgor pressure of mature leaves but may have been related to turgor pressure in the growing tip.
22
Hatzilazarou, Stefanos, Stefanos Kostas, Theodora Nendou, and Athanasios Economou. "Conservation, Regeneration and Genetic Stability of Regenerants from Alginate-Encapsulated Shoot Explants of Gardenia jasminoides Ellis." Polymers 13, no. 10 (2021): 1666. http://dx.doi.org/10.3390/polym13101666.
Full textAbstract:
The present study demonstrates the potential of the alginate encapsulation of shoot tips and nodal segments of Gardenia jasminoides Ellis, the short-term cold storage of artificial seeds and subsequent successful conversion to desirable, uniform and genetically stable plantlets. Shoot tips and first-node segments below them, derived from shoots of in vitro cultures, responded better than second-to-fourth-node segments on agar-solidified Murashige and Skoog (MS) nutrient medium and thus, they were used as explants for alginate encapsulation. Explant encapsulation in 2.5% sodium alginate in combination with 50 mM of calcium chloride resulted in the production of soft beads, while hardening in 100 mM of calcium chloride formed firm beads of uniform globular shape, suitable for handling. The addition of liquid MS nutrient medium in the sodium alginate solution doubled the subsequent germination response of the beads. The maintenance of alginate beads under light favored their germination response compared to maintenance in darkness. Encapsulated shoot tip explants of gardenia, which were stored at 4 °C for 4, 8 or 12 weeks, showed a gradual decline in their regeneration response (73.3, 68.9, 53.3%, respectively), whereas, non-encapsulated explants (naked), stored under the same time durations of cold conditions, exhibited a sharp decline in regeneration response up to entirely zeroing (48.9, 11.1, 0.0%, respectively). Shoots, derived from 12-week cold-stored encapsulated explants, were easily rooted in solid MS nutrient medium with the addition of 0.5 μM of Indole-3-acetic acid (IAA) and after transplantation of the rooted plantlets individually to pots containing a peat–perlite (3:1, v/v) substrate, they were successfully acclimatized in the greenhouse under the gradual reduction of 75 or 50% shading with survival rates of 95–100%. The genetic stability of the acclimatized plantlets was assessed and compared with the mother plant using inter simple sequence repeat (ISSR) markers. ISSR analysis confirmed that all regenerated plantlets were genetically identical to the mother plant. This procedure of artificial seed production could be useful for the short-term storage of germplasm and the production of genetically identical and stable plants as an alternative method of micropropagation in Gardenia jasminoides.
23
Kohler, Annika E., and Roberto G. Lopez. "Daily Light Integral Influences Rooting of Herbaceous Stem-tip Culinary Herb Cuttings." HortScience 56, no. 4 (2021): 431–38. http://dx.doi.org/10.21273/hortsci15482-20.
Full textAbstract:
Domestic production of culinary herbs continues to increase in the United States. Culinary herbs are primarily propagated by seed; however, some herbs have poor germination rates and slow growth. Thus, there are advantages of propagating herbs by vegetative stem-tip cuttings as they lead to true-to-type plants and a shortened production time. Previous research of ornamental young plants and finished culinary herbs have shown a reduction in rooting time and increases in plant quality with increases in the photosynthetic daily light integral (DLI). To our knowledge, little to no research has addressed how the DLI influences culinary herb liner quality. Therefore, the objectives of this study were to quantify morphological traits of five economically important culinary herbs when grown under DLIs ranging from 2.8 to 16.4 mol·m−2·d−1. Stem-tip cuttings of Greek oregano (Origanum vulgare var. hirtum), rosemary ‘Arp’ (Rosmarinus officinalis), sage ‘Extrakta’ (Salvia officinalis), spearmint ‘Spanish’ (Mentha spicata), and thyme ‘German Winter’ (Thymus vulgaris) were excised from stock plants and rooted under no shade or aluminum shading of 36%, 56%, or 76% to create a range of DLI treatments. After 9 days (spearmint) or 16 days (all other genera) of DLI treatments, the root, shoot, and total dry mass of all culinary herb liners generally increased by 105% to 449%, 52% to 142%, and 82% to 170%, respectively, as the DLI increased from 2.8 to 16.4 mol·m−2·d−1 or genus-specific DLI optimums. Stem length of oregano, spearmint, and thyme decreased by 37%, 28%, and 27%, respectively, as the DLI increased from 2.8 to 16.4 mol·m−2·d−1. However, stem length of rosemary and sage were unaffected by the DLI. The quality index of all genera was greatest at DLIs from 10.4 to 16.4 mol·m−2·d−1. Furthermore, all culinary herbs grown under a DLI of ≤6 mol·m−2·d−1 had low root and shoot dry mass accumulation; and oregano, spearmint, and thyme were generally taller. Therefore, DLIs between 10 to 12 mol·m−2·d−1 should be maintained during culinary herb propagation, because a DLI ≥16 mol·m−2·d−1 may be deleterious and energy inefficient if supplemental lighting use is increased.
24
Yang, Chen, Jiangfei Liu, Xin Qin, et al. "Effect of Nitric Oxide on Browning of Stem Tip Explants of Malus sieversii." Horticulturae 9, no. 11 (2023): 1246. http://dx.doi.org/10.3390/horticulturae9111246.
Full textAbstract:
Browning is a major problem in the tissue culture of woody plants. Previous studies have shown that nitric oxide (NO) plays a role in regulating plant responses to stress, but its effect on browning in the tissue culture of Malus remains unclear. This study aimed to investigate the impact of exogenous NO donor sodium nitroprusside (SNP) on the browning of Malus sieversii stem tip explants. The results demonstrated that the addition of 50 μM SNP significantly reduced explant browning. Further analysis revealed that exogenous NO decreased the browning index (BD) and levels of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion radical O2−. Additionally, NO treatment increased the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). NO treatment also enhanced the activity of phenylalanine ammonia lyase (PAL), which contributed to the accumulation of flavonoids and inhibited the activity of polyphenol oxidase (PPO) and peroxidase (POD), which are key enzymes involved in the browning process. Furthermore, 50 μM SNP significantly promoted the accumulation of non-enzymatic antioxidants such as proline (Pro), soluble sugar (SS), and soluble protein (SP). Therefore, the results suggest that NO is able to counteract excessive reactive oxygen species (ROS) damage by enhancing both the enzymatic and non-enzymatic antioxidant systems, resulting in a reduction in browning in stem tip explants. Consequently, an improvement in the in vitro propagation efficiency of Malus sieversii shoot tip explants can be achieved.
25
Emoghene, B. O., M. Idu, C. R. Eke, and O. Asemota. "Effects Of Different Sterilization Regimes & Growth Regulators On Micropropagation Of Female Date Palm (Phoenix dactylifera L.)." Nigerian Journal of Biotechnology 37, no. 1 (2020): 159–68. http://dx.doi.org/10.4314/njb.v37i1.17.
Full textAbstract:
The success of in vitro culture techniques is always hampered by microbial contamination. The present study was carried out to develop an efficient protocol for date palm explants sterilization for successful somatic embryos induction and plantlets formation of some date palm varieties. The shoot tips were treated with different sterilizing agents at different concentrations and durations of exposure. The use of ethanol (70%), sodium hypochlorite (3.5% & 70%) and mercuric chloride (0.2%) with or without addition of Tween-20 had different effects on decontamination of the date palm explants. The percentage of explants contaminated with bacteria for sterilants 1, 2 and 4 was 18.8%, 6.3% and 6.3% respectively while 25%, 37.5%, 31.25% and 6.25% were contaminated with fungi for sterilants 1, 2, 3 and 4 respectively. Under the conditions used, a combination of antioxidants (Citric and Ascorbic acids at 100mg/l), 0.2% mercuric chloride and 3.5% sodium hypochlorite solution with 3 drops/100ml of Tween-20 helped in the reduction of chlorosis, contamination and die-back in the shoot tip explants. The explants were further cultured in appropriate media for callus initiation and subsequent somatic embryo induction. Optimal embryogenic callus was obtained from the shoot explant of sterilant number 4 which had the minimal contamination and die-back of all the cultures. After 3 subcultures, the somatic embryos formed were multiplied for shoot development. From this study, we established that the use of appropriate surface sterilant at suitable concentration and duration of exposure of date palm explant to it is indispensable for maximum responses of in vitro cultures.
 Keywords: Date palm, Microbial contamination, Sterilizing agents, in vitro, Somatic embryos
26
Evans, Glenn J., Robin R. Bellinder, and Martin C. Goffinet. "Herbicidal Effects of Vinegar and a Clove Oil Product on Redroot Pigweed (Amaranthus retroflexus) and Velvetleaf (Abutilon theophrasti)." Weed Technology 23, no. 2 (2009): 292–99. http://dx.doi.org/10.1614/wt-08-158.1.
Full textAbstract:
Weed management can be difficult and expensive in organic agricultural systems. Because of the potentially high cost of the natural product herbicides vinegar and clove oil, their efficacy with regard to weed species growth stages needs to be determined. A further objective was to identify anatomical and morphological features of redroot pigweed and velvetleaf that influence the effectiveness of vinegar and clove oil. Research was conducted on greenhouse-grown cotyledon, two-leaf, and four-leaf redroot pigweed and velvetleaf. Dose–response treatments for vinegar included 150-, 200-, 250-, and 300-grain vinegar at 318 L/ha and at 636 L/ha. Clove oil treatments included 1.7, 3.4, 5.1, and 6.8% (v/v) dilutions of a clove oil product in water (318 L/ha), and a 1.7% (v/v) dilution in 200-grain vinegar (318 L/ha). An untreated control was included. Separate plantings of velvetleaf and pigweed were treated with vinegar or clove oil and were used to study anatomical and morphological differences between the two species. Redroot pigweed was easier to control with both products than velvetleaf. Whereas 200-grain vinegar applied at 636 L/ha provided 100% control (6 d after treatment [DAT]) and mortality (9 DAT) of two-leaf redroot pigweed, this same treatment on two-leaf velvetleaf provided only 73% control and 18% mortality. The obtuse leaf blade angle in velvetleaf moved product away from the shoot tip, whereas in pigweed, the acute leaf blade angle, deep central leaf vein, and groove on the upper side of the leaf petiole facilitated product movement toward the stem axis and shoot tip. For both species, and at all application timings, 150-grain vinegar at 636 L/ha provided control equal to that of 300-grain vinegar at 318 L/ha. As growth stage advanced, control and biomass reduction decreased and survival increased. Application timing will be critical to maximizing weed control with vinegar and clove oil.
27
Wang, Yuqi, Ruihong Li, Demou Li, et al. "NIP1;2 is a plasma membrane-localized transporter mediating aluminum uptake, translocation, and tolerance in Arabidopsis." Proceedings of the National Academy of Sciences 114, no. 19 (2017): 5047–52. http://dx.doi.org/10.1073/pnas.1618557114.
Full textAbstract:
Members of the aquaporin (AQP) family have been suggested to transport aluminum (Al) in plants; however, the Al form transported by AQPs and the roles of AQPs in Al tolerance remain elusive. Here we report that NIP1;2, a plasma membrane-localized member of the Arabidopsis nodulin 26-like intrinsic protein (NIP) subfamily of the AQP family, facilitates Al-malate transport from the root cell wall into the root symplasm, with subsequent Al xylem loading and root-to-shoot translocation, which are critical steps in an internal Al tolerance mechanism in Arabidopsis. We found that NIP1;2 transcripts are expressed mainly in the root tips, and that this expression is enhanced by Al but not by other metal stresses. Mutations in NIP1;2 lead to hyperaccumulation of toxic Al3+ in the root cell wall, inhibition of root-to-shoot Al translocation, and a significant reduction in Al tolerance. NIP1;2 facilitates the transport of Al-malate, but not Al3+ ions, in both yeast and Arabidopsis. We demonstrate that the formation of the Al-malate complex in the root tip apoplast is a prerequisite for NIP1;2-mediated Al removal from the root cell wall, and that this requires a functional root malate exudation system mediated by the Al-activated malate transporter, ALMT1. Taken together, these findings reveal a critical linkage between the previously identified Al exclusion mechanism based on root malate release and an internal Al tolerance mechanism identified here through the coordinated function of NIP1;2 and ALMT1, which is required for Al removal from the root cell wall, root-to-shoot Al translocation, and overall Al tolerance in Arabidopsis.
28
Dilsha, Davis, and S. Narasimhan. "Detrimental Effects of Lithium on in vitro Seedlings of Pea (Vigna radiata)." Research Journal of Biotechnology 19, no. 1 (2023): 87–90. http://dx.doi.org/10.25303/1901rjbt087090.
Full textAbstract:
The global demand for lithium-ion batteries has raised concerns about environmental consequences stemming from lithium leaching. In this study, we investigated the effects of lithium, sourced from Li2SO4, on in vitro seed germination and seedling growth of green moong (Vigna radiata). Our experiments used woody plant medium supplemented with 1 mg/l naphthalene acetic acid (NAA) and 2 mg/l benzyl adenine (BA). We observed that in vitro seed germination remained unaffected by lithium concentration. However, at concentrations of 3-5 mg/l of lithium, significant changes were observed in stem parameters including growth reduction, shoot tip damage and stem discolouration. Root growth was inhibited at lithium concentrations of 4 and 5 mg/l. Additionally, we noted leaf abscission, dark colouration and reduced leaf area in a dose-dependent manner. Necrotic lesions were not observed in the seedlings. Chlorophyll accumulation, phenolic content and peroxidase (POD) activity showed enhancement with increasing lithium concentration. Our data analysis strongly suggests dose-dependent toxicity in young seedlings under in vitro conditions. These findings shed light on the potential ecological implications of lithium leaching from retired batteries.
29
Garcia, M. Elena, Lorraine P. Berkett, and Terry Bradshaw. "The Effect of Surround WP on Apple Productivity and Fruit Quality in a Vermont Apple Orchard." HortScience 40, no. 4 (2005): 1129B—1129. http://dx.doi.org/10.21273/hortsci.40.4.1129b.
Full textAbstract:
Surround WP, a kaolin clay-based biopesticide product, is a potential alternative to some organophosphates used in apple orchards for the management of pests, such as codling moth. In addition, Surround has been reported to have important nontarget horticultural impacts because of its effect on canopy temperature reduction. The label for use of Surround states: “When applied at recommended rates and frequencies, benefits such as increased plant vigor and improved yields may occur in certain apple cultivars.” However, most of the research on nontarget effects has been conducted in warmer, semiarid environments. The objectives of this 3-year (2002–04) interdisciplinary research project were to determine potential nontarget effects of Surround WP application on apple tree vigor, productivity, and fruit quality in the relatively cool and moist climate of the Northeast. The research was conducted at the UVM Horticultural Research Center in South Burlington, Vt., on `McIntosh'/M26 trees. The experiment used a completely randomized design with five treatments replicated six times. Each replicate consisted of single tree plots. Treatments included: 1) Surround beginning at green tip plus fungicides; 2) Surround beginning at green tip without fungicides; 3) Surround beginning at petal fall plus fungicides; 4) standard IPM; and 5) nontreated control. Results indicate no significant differences among treatments 1, 3, and 4 (treatments that included fungicide applications) in vegetative shoot length, spur characteristics, blossom number, fruit weight, firmness, soluble solids, and fruit calcium levels. Trees treated with Surround had significantly lower yield efficiencies in 2003 and 2004 than trees under IPM treatment.
30
Greene, Duane W., and Paul Miller. "Effects of Growth Regulator Sprays and Notching on Growth and Branching of ‘Starkrimson Delicious’ Apple Trees." Journal of the American Society for Horticultural Science 113, no. 1 (1988): 18–23. http://dx.doi.org/10.21273/jashs.113.1.18.
Full textAbstract:
Abstract A block of 2-year-old ‘Starkrimson Delicious’ apple (Malus domestica Borkh.) trees growing in Somerville, Victoria, Australia were treated with 0 to 500 ppm BA when terminal growth was 2 cm. BA application initially increased the rate of lateral shoot growth. However, the growth rate rapidly slowed and extension growth on the lateral shoots stopped earlier than on untreated trees. There was a linear increase in the number of lateral shoots and a linear reduction in the length of these lateral shoots as the concentration of BA was increased. BA forced more lateral shoots to grow at the tip of the branch than at the base, although shoots at the base of the limbs grew longer. A reduced concentration of BA was required to stimulate spurs to grow out into lateral shoots on the vigorous, more upright central leader. Lateral shoots were longer on the central leader than on the scaffold branches, indicating tree and/or branch vigor may be a major factor in producing good scaffold limb development following BA application. Notching forced more spurs to form lateral shoots on the central leader, and these shoots grew longer than those on the scaffold limbs. Notching increased the number of buds developing into lateral shoots following BA application. May and Baker 25-105 increased the number of lateral shoots on a tree. This result occurred both on untreated trees and on those that previously received 400 ppm BA. Reducing the number of lateral shoots by pinching apices of shoots soon after BA application was the most effective method to increase the length of BA-induced lateral shoots. Chemical names used: N-(phenylmethyl)-1H-purine-6-amine (BA) (2-chloroethyl)phosphonic acid (ethephon), butanedioic acid mono(2,2-diemthylhydrazide) (daminozide), propyl 3-t-butylphenoxyacetate (May and Baker 25-105).
31
Noimusik, Paramaporn, Sompong Te-chato, and Sureerat Yenchon. "Some Agronomical and Physiological Characteristics of Sang Yod Phatthalung Rice from In Vitro Regenerated Plant After Transfer to Clay Soil in Field Conditions." Trends in Sciences 20, no. 12 (2023): 6959. http://dx.doi.org/10.48048/tis.2023.6959.
Full textAbstract:
Sang Yod Phatthalung rice is indica rice and grown as Geographical Indications (GI) in Patthalung province. Its dark red color seed contains high antioxidant activity that helps reduction in the risk of some chronic diseases such as diabetes, cancer, and cardiovascular diseases. So far, yield per planting area of this rice is still low. Thus, application of PGRs might play an alternative role in agronomical and physiological characteristics leading to improving yield of this rice. First, shoot tips of Sang Yod Phatthalung rice were cultured to induce multiple shoots and root on liquified PGR-free oil palm culture medium (OPCM) with different concentrations of 6-benzyladenine (BA) (0, 0.5, 1, 1.5 mg/L) alone or in combination with 1-naphthaleneacetic acid (NAA) (0 and 0.5 mg/L). Complete plants were acclimatized to field condition at Phatthalung Rice Research Station (PRRS). After acclimatization for 120 and 140 days, some agronomical and physiological characteristics of rice plant obtained from different PGR containing OPCM were statistically compared. A 2×4 factorial design in RCBD with 4 replication was performed. The results were clearly demonstrated that adding BA in the culture medium increase plant height, number of panicles, panicle length and leaf chlorophyll content. Plantlets obtained from in vitro culturing shoot tip on 0.5 mg/L BA containing medium gave the highest results in average plant height at 189.50 cm, number of panicles at 34.00 panicles, panicle length at 32.50 cm and leaf chlorophyll content at 39.65 SPAD unit. The results from this present study indicated the production of new plant types or characteristics for Sang Yod Phatthalung rice for high yield in future. HIGHLIGHTS The effect of concentrations of PGRs, and culture conditions on agronomical and physiological characteristic were evaluated 5 mg/L BA-derived plants germinated in vitro gave higher results than ex vitro in agronomical and physiological characteristic Addition of 0.5 mg/L BA in the medium increases the plant height, number of panicles, panicle length and leaf chlorophyll content 5 mg/L BA-derived plants in vitro gave the highest plant height, number of panicles, panicle length, and leaf chlorophyll content at 189.50 cm, 34.00 panicles, 32.50 cm, and 39.65 SPAD units, respectively GRAPHICAL ABSTRACT
32
Wu, X., L. Wang, and Mark Roh. "Reduction of leaf tip burns of Ornithogalum dubium by controlling the temperature during bulb storage and greenhouse forcing to produce quality plants." Advances in Horticultural Science 36, no. 1 (2022): 3–11. http://dx.doi.org/10.36253/ahsc-11568.
Full textAbstract:
Production of quality potted Ornithogalum dubium Houtt. plants were investigated under multiple conditions: pre-planting treatment at 10, 16, and 22°C for 40 days from Sept. 21 (stage A; ST-A) during bulb storage and then bulbs were potted. After potting, post-planting treatment at 15/12, 18/15, and 21/18°C (day/night) during stage B for 35 days from Nov. 2 (stage B; ST-B), and at 15/12 and 21/18°C during stage C for 30 days from Dec. 7 (stage C; ST-C) during greenhouse forcing was applied. Leaf tissue analyses for macro- and micro-nutrients were performed to investigate the cause of leaf tip burn symptom (LTB). Three criteria for quality of the plants at flowering were established: (1) LTB occurs on less than 1.5 leaves per plant. (2) the number of days to flower is less than 115 days, the length of the third leaf counted from the crown (the junction of the shoot and roots) is shorter than 11.5 cm, and the width is narrower than 2.5 cm; the scape length is shorter than 15 cm, and there are more than 45 flowers. (3) the leaf spread and morphology (leaf spread) and the pattern of the scape curvature (scape growth) have a score of less than 1.5. The following conditions are optimal to produce quality plants based on these three criteria: (1) Pre-planting bulbs treatment was applied at 10 or 16°C during ST-A, and forcing was performed at 15/12°C during ST-B and 21/18°C during ST-C. These conditions accelerated flowering, produced straight scape growth and upward (erect) growing leaves, and yielded acceptable leaf length and width. (2) The incidence of LTB was minimal at 10°C or possibly 16°C during ST-A, and at 15/12°C in ST-B and at 21/18°C in ST-C during greenhouse forcing. Leaf tip burn symptom was observed in both young and old leaves and was caused by a high boron (B) concentration (218-230 ppm) and possibly a high zinc (Zn) concentration (155-159 ppm) in O. dubium. A low calcium (Ca) concentration was not the cause of LTB. Although LTB cannot be avoided, it can be minimized by temperature manipulation during pre- and post-planting phase to produce high quality potted plants.
33
Mwangangi, Maureen, Ivan Obare, Stephen Khisa, Elizabeth Nduta, Salome Kivuva, and Jully Nyapur. "Efficacy of thermotherapy combined with chemotherapy and meristem tip culture in reducing Cassava brown streak virus in infected cassava." African Phytosanitary Journal Volume 1 Issue 1 1, no. 1 (2019): 19–25. http://dx.doi.org/10.52855/bdmb2955.
Full textAbstract:
Thermotherapy, chemotherapy and meristem tip culture have been used either alone or in combination to eliminate viruses from plants. . The objective of this study was to determine the efficacy of combining thermotherapy with meristem tip culture and chemotherapy on the reduction of CBSV from infected cassava.Cassava Brown Streak Virus infected cuttings of Guzo variety collected from Coast region of Kenya, were established and maintained in a greenhouse at the Plant Quarantine Station, Kenya Plant Health Inspectorate Service (KEPHIS) in Muguga. Cassava leaves were sampled from eighteen plants and virus indexing done using RT-PCR with virus specific primers. Those confirmed to be positive for CBSV were used as initiation materials for the prospective test plants. From the initiated tissue culture materials, the 2nd subcultures were subjected to heat treatment at 38°C for 21 days. They were later subjected to ribavirin treatment at varying concentrations of (10mg/l, 20mg/l, and 30mgl) then left to establish for 14 days. Meristems of 1mm were excised from heat treated plantlets at 38°C for 21 days and cultured in vitro in modified Murasgige and skoog media. Nodal plantlets of 10mm not subjected to any treatment were used as controls. There was a significant difference (P<0.01) in the number of plants that survived among the treatments. Thermotherapy combined with chemotherapy resulted in complete mortality of plants due to the high stress levels from the high temperatures combined with the phytotoxic effect of the ribavirin. Thermotherapy followed by excision of meristem tips (1mm) resulted in 68.8% shoot survival with 84% being virus-free. Thermotherapy combined with meristem culture was successfully employed to produce CBSV-free cassava plants. Key words: Cassava Brown steak virus, Chemotherapy, meristem culture, Thermotherapy
34
Rugini, Eddo, Cristian Silvestri, Marilena Ceccarelli, Rosario Muleo, and Valerio Cristofori. "Mutagenesis and Biotechnology Techniques as Tools for Selecting New Stable Diploid and Tetraploid Olive Genotypes and Their Dwarfing Agronomical Characterization." HortScience 51, no. 7 (2016): 799–804. http://dx.doi.org/10.21273/hortsci.51.7.799.
Full textAbstract:
In Olea europaea L. subsp. europaea, tetraploid genotypes do not exist in nature. Herein, we report the first example of selection of tetraploid olive plants, obtained by combining physical mutagenesis and biotechnology techniques. Stable tetraploid (4n) and diploid (2n) genotypes were isolated in vitro through shoot-tip fragmentation of two mixoploid mutants derived from the gamma irradiation of self-incompatible Leccino and self-compatible Frantoio cultivars. In this study, the stable mutants FRM5-4n, FRM5-2n, LM3-4n, and LM3-2n were characterized in the field for vegetative and reproductive behavior with the aim to use them as varieties or dwarfing rootstocks. The stable 4n genotype of Leccino acquired self-fertility whereas the 4n Frantoio maintained it. A high and constant yield was showed by LM3-2n during 9 years of observation, maintaining the same oil quality as the Leccino wild type (wt). Moreover, the LM3-2n acquired the capacity to be intercompatible with the diploid mutant Leccino dwarf (LD) and with the Leccino wt. This acquired property would allow for a reduction of heterozygosity in the offspring, if crossed with each other for some generations and with the Leccino wt, because it is a sort of self-fertilization. When used as rootstocks, both 4n and 2n Leccino mutants proved to be very effective for reducing the scion size of the high-vigor Canino cultivar, which is well known for its excellent extravirgin oil. Finally, it was demonstrated that the self-grafting of vigorous cultivar caused a reduction in plant size, thus suggesting that it is possible to produce semidwarf plants from vigorous genotypes to consider them in high-density olive orchards.
35
Tan, Zhen, Fengzhen Liu, Yongshan Wan, et al. "Morphological and Physiological Mechanism of Activating Insoluble Inorganic Phosphorus of Different Peanut (Arachis hypogaea L.) Varieties under Low Phosphorus." Agriculture 13, no. 12 (2023): 2270. http://dx.doi.org/10.3390/agriculture13122270.
Full textAbstract:
To reduce the application of phosphorus fertilizer and improve phosphorus efficiency in peanut (Arachis hypogaea L.) production, six peanut varieties with different phosphorus activation efficiencies were selected, and the root morphology, physiological indexes, and types and content of organic acids secreted were measured via a hydroponic experiment for 20 days. We analyzed the difference in calcium phosphate activation between peanut seedlings cultivated under low-phosphorus (LP, 0.01 mmol/L KH2PO4) and normal phosphorus (NP, 0.6 mmol/L KH2PO4) conditions and explored the physiological mechanisms of different peanut varieties on the activation efficiency of insoluble inorganic phosphorus. The results showed that under LP conditions, the root length, root surface area, root volume, root tip number, and root activity of the efficient P activation varieties were 18.31%, 17.50%, 15.23%, 20.00%, and 50.90% higher than those of the inefficient P activation varieties respectively. The reduction range of the nutrient solution pH of the high-efficiency varieties was 74.48% higher than that of the low-efficiency varieties under LP conditions. The total amount of organic acid secreted by the efficient P activation varieties increased by 236.07% on average under LP conditions compared with that under NP conditions. In comparison, the average increase in inefficient P activation varieties was only 16.36%. Under low P stress, the peanut varieties with high-efficiency P activation could increase the activation of insoluble inorganic P in the environment mainly by changing the root architecture and increasing the root-shoot ratio, root activity, and root proton and organic acid secretion.
36
Chang, Yao-Chien, and William B. Miller. "The Development of Upper Leaf Necrosis in Lilium `Star Gazer'." Journal of the American Society for Horticultural Science 130, no. 5 (2005): 759–66. http://dx.doi.org/10.21273/jashs.130.5.759.
Full textAbstract:
A necrotic disorder occurs on upper leaves of many oriental hybrid lily (Lilium L.) cultivars, including the most-widely-grown `Star Gazer'. We term this disorder “upper leaf necrosis” (ULN) and hypothesize that it is a calcium (Ca) deficiency. We demonstrated that Ca concentration in necrosed tissues was nearly six-fold below that of normal leaves (0.10% vs. 0.57% dry weight), and that Ca concentration was negatively associated with percentage necrosed leaf area. It was concluded that ULN is a Ca deficiency disorder. When the symptoms were slight, early ULN symptoms appeared as tiny depressed spots on the lower surface of the leaf, or as water-soaked areas when the disorder was severe. Most commonly, ULN began on the leaf margin. The injured areas turned brown, leading to leaf curling, distortion, or tip death. ULN occurred on leaves associated with flower buds and leaves immediately below the flower buds. For the plants grown from 16-18 cm circumference bulbs, the five leaves directly below the flower buds and larger leaves associated with the 1st and the 2nd flower buds were most susceptible. In general, flower buds were not affected by ULN, and continued to develop and flower normally, even though they were associated with subtending, highly distorted leaves. Eighty-five percent of plants began to exhibit ULN symptoms 30-40 days after planting (i.e., 24-34 days after shoot emergence). This was the stage when the 6th or 7th leaf under the bottom flower bud was just unfolded. Light was not the main factor that initiated ULN, however, ULN severity was greatly increased by light reduction, as leaf transpiration was reduced.
37
Gillette, Nancy E., John D. Stein, Donald R. Owen, Jeffrey N. Webster, and Sylvia R. Mori. "Pheromone-based disruption of Eucosma sonomana and Rhyacionia zozana (Lepidoptera: Tortricidae) using aerially applied microencapsulated pheromone." Canadian Journal of Forest Research 36, no. 2 (2006): 361–68. http://dx.doi.org/10.1139/x05-152.
Full textAbstract:
Two aerial applications of microencapsulated pheromone were conducted on five 20.2 ha plots to disrupt western pine shoot borer (Eucosma sonomana Kearfott) and ponderosa pine tip moth (Rhyacionia zozana (Kearfott); Lepidoptera: Tortricidae) orientation to pheromones and oviposition in ponderosa pine plantations in 2002 and 2004. The first application was made at 29.6 g active ingredient (AI)/ha, and the second at 59.3 g AI/ha. Baited sentinel traps were used to assess disruption of orientation by both moth species toward pheromones, and E. sonomana infestation levels were tallied from 2001 to 2004. Treatments disrupted orientation by both species for several weeks, with the first lasting 35 days and the second for 75 days. Both applications reduced infestation by E. sonomana, but the lower application rate provided greater absolute reduction, perhaps because prior infestation levels were higher in 2002 than in 2004. Infestations in treated plots were reduced by two-thirds in both years, suggesting that while increasing the application rate may prolong disruption, it may not provide greater proportional efficacy in terms of tree protection. The incidence of infestations even in plots with complete disruption suggests that treatments missed some early emerging females or that mated females immigrated into treated plots; thus operational testing should be timed earlier in the season and should comprise much larger plots. In both years, moths emerged earlier than reported previously, indicating that disruption programs should account for warmer climates in timing of applications. The AIs we tested are behaviorally active for 13 other species of Rhyacionia and six other species of Eucosma, so the approach may have wide application.
38
Singh, Harminder Pal, Daizy R. Batish, Shalinder Kaur, Ravinder K. Kohli, and Komal Arora. "Phytotoxicity of the Volatile Monoterpene Citronellal against Some Weeds." Zeitschrift für Naturforschung C 61, no. 5-6 (2006): 334–40. http://dx.doi.org/10.1515/znc-2006-5-606.
Full textAbstract:
A study was undertaken to assess the phytotoxicity of citronellal, an oxygenated monoterpenoid with an aldehyde group, towards some weedy species [Ageratum conyzoides L., Chenopodium album L., Parthenium hysterophorus L., Malvastrum coromandelianum (L.), Garcke, Cassia occidentalis L. and Phalaris minor Retz.]. A significant effect on weed emergence and early seedling growth was observed in a dose-response based laboratory bioassay in a sand culture. Emergence of all test weeds was completely inhibited at 100 μg/g sand content of citronellal. Seeds of A. conyzoides and P. hysterophorus failed to emerge even at 50 μg/g content. Root length was inhibited more compared to shoot length. The failure of root growth was attributed to the effect of citronellal on the mitotic activity of growing root tips cells as ascertained by the onion root tip bioassay. At 2.5 mm treatment of citronellal, mitosis was completely suppressed and at higher concentrations cells showed various degrees of distortion and were even enucleated. The post-emergent application of citronellal also caused visible injury in the form of chlorosis and necrosis, leading to wilting and even death of test weeds. Among the test weeds, the effect was severe on C. album and P. hysterophorus. There was loss of chlorophyll pigment and reduction in cellular respiration upon citronellal treatment indicating the impairment of photosynthetic and respiratory metabolism. Scanning electron microscopic studies in C. occidentalis leaves upon treatment of citronellal revealed disruption of cuticular wax, clogging of stomata and shrinkage of epidermal cells at many places. There was a rapid electrolyte leakage in the leaf tissue upon exposure to citronellal during the initial few hours. In P. minor electrolyte leakage in response to 2 mm citronellal was closer to the maximum leakage that was obtained upon boiling the tissue. The rapid ion leakage is indicative of the severe effect of citronellal on the membrane structure and loss of membrane integrity. In all, the study concludes that citronellal causes a severe phytotoxicity on the weeds.
39
Kyser, Guy B., J. Earl Creech, Jimin Zhang, and Joseph M. DiTomaso. "Selective Control of Medusahead (Taeniatherum caput-medusae) in California Sagebrush Scrub using Low Rates of Glyphosate." Invasive Plant Science and Management 5, no. 1 (2012): 1–8. http://dx.doi.org/10.1614/ipsm-d-11-00032.1.
Full textAbstract:
AbstractAlthough glyphosate is typically used as a nonselective herbicide, low rates have the potential to provide selective control of seedling annuals in the understory of established perennial plants. In a repeated experiment on two adjacent sites at a single location near Alturas, CA (2009 and 2010), we evaluated the efficacy of glyphosate at several different rates on medusahead and nontarget species in northern California sagebrush scrub. We applied glyphosate at 10 rates ranging from 0 to 709 g ae ha−1 (0 to 18 oz product acre−1) at three separate timings in each trial: mid-March (medusahead in early seedling stage), late April to early May (tillering), and late May to early June (boot to early head). Plots measured 3 m by 9 m (10 ft by 30 ft) and were arranged in randomized complete blocks with four replications for each rate and timing. We visually estimated vegetative cover for all dominant species in July before medusahead seed drop using three 1-m2 quadrats per plot. Medusahead cover declined with increasing rates of glyphosate, and the middle application timing (at tillering) was the most effective. In rate series regression models, we achieved 95% control of medusahead with 160 g ae ha−1 glyphosate in midseason 2009, compared with 463 g ae ha−1 in early season and 203 g ae ha−1 in late season. In 2010, we achieved 95% control with 348 g ae ha−1 in midseason, compared with > 709 g ae ha−1 in early season. Medusahead seed production reflected changes in cover, though individual plants tended to produce more seed at low densities. We attribute reduced control early in the season and poorer overall control in 2010 to greater tolerance of medusahead to glyphosate at lower temperatures. Treatment effects on big sagebrush, as indicated by shoot tip vigor, were minor, although the midseason timing caused a slight reduction in vigor. These results show that low rates of glyphosate (158 to 315 g ae ha−1) at a treatment timing corresponding to medusahead tillering can give economical and effective control of medusahead without long-term damage to big sagebrush.
40
Zheng, Wei, Jesús García, Pedro Balda, and Fernando Martínez de Toda. "Effects of late winter pruning at different phenological stages on vine yield components and berry composition in La Rioja, North-central Spain." OENO One 51, no. 4 (2017): 363. http://dx.doi.org/10.20870/oeno-one.2017.51.4.1863.
Full textAbstract:
Aims: Under global warming, the desynchrony between technology maturity and phenolic maturity of wine grapes is a worthy concern. Late winter pruning (LWP) has been proved to be an effective way to delay the grape phenological stages. The aim of this study was to evaluate the effects of LWP at different phenological stages (based on Baillod & Baggiolini system) on the delay of the grape ripening, on vine yield components as well as on berry composition, among others, the anthocyanin to sugar ratio.Methods and results: The two-year (2015 and 2016) trial was conducted in Rioja wine region (North of Spain) on Maturana vines and in each year, four pruning treatments were carried out taking apical buds/shoots as reference: (1) winter pruning at stage A (WPA; dormant bud); (2) LWP at stage C (LWPC; green shoot tip) in 2015 and at stage F (LWPF; inflorescence clearly visible) in 2016; (3) LWP at stage G (LWPG; inflorescences separated); (4) LWP at stage H (LWPH; flowers separated). LWPC failed to delay the late phenological stages and did not exert important influence on vine yield and berry composition. LWPG and LWPH succeeded to delay all the phenological stages of grapes to a great extent and created a considerably cooler and longer ripening period compared to WPA. Vine yield was not affected by LWPF and was reduced significantly (averagely by 41%) by LWPG. LWPH lead to great losses in yield (averagely by 67%), especially in 2015. LWPG did not change the fruit composition while LWPH increased the ratio of anthocyanin to sugar and helped to maintain a relatively high level of acidity in berries.Conclusions: The primary cause of the decline in production seems to be the losses of flowers and/or the reduction in fruit set percentage in the current season, instead of the losses in inflorescences within buds in the previous season. For Maturana grapes, LWP after the stage F would reduce the vine yield and could be applied as an alternative to the time consuming cluster thinning to meet the needs of yield control. Delaying the winter pruning to stage H could improve the fruit quality in spite of the greater risk of botrytis and a serious decline in production.Significance and impact of the study: The outcomes of this research open a door for the winegrowers to realize the yield control in a simple way. Also, for those who only pursue wines of top quality (regardless of production), a very late winter pruning might provide them with high-quality grapes. Moreover, as can be seen obviously from our results, viticulturists could postpone the budburst date to whatever extent they wish thus reducing the risk of spring frost injury to zero, though this point is not our focus in the study.
41
Logan, Anne K., Justin A. France, James M. Meyers, and Justine E. Vanden Heuvel. "Modifying Shoot Tip Management to Reduce Cluster Compactness and Lateral Emergence in ‘Cabernet franc’ Grapevines." HortScience 56, no. 6 (2021): 634–41. http://dx.doi.org/10.21273/hortsci15705-21.
Full textAbstract:
To manage excessive vine vigor, Vitis vinifera L. ‘Cabernet franc’ grapevines were subjected to shoot wrap, shoot tuck, and hedge (control) techniques at one of two growth stages (shoot tips at 30 cm or at 90 cm above the top catch wire) in the Finger Lakes region of New York from 2016 to 2019. Shoot tuck and shoot wrap both reduced fruit zone lateral counts, with reductions up to 33% and 56% compared with the control, respectively. Shoot wrap reduced fruit zone lateral lengths by up to 50% and cluster compactness by up to 2.4 fewer berries per centimeter rachis. Although shoot wrap improved spray penetration to the clusters by up to 28% in one year of the study, enhanced point quadrat analysis indicated that occlusion layer number was not affected by the treatments. Shoot tip management treatments did not affect yield or fruit composition consistently. Phenological timing of shoot tip management had little impact on vine growth. Although the impacts of these modified shoot tip management practices on lateral emergence and cluster morphology were generally positive, the required hand labor to apply the treatments on a large scale may discourage the use of these management practices.
42
DE GROOT, JORIS R., JUTTA M. SCHROEDER-TANKA, JAAP VISSER, ALBERT R. WILLEMS, and WILLEM G. DE VOOGT. "Clinical Results of Far-Field R-Wave Reduction with a Short Tip-Ring Electrode." Pacing and Clinical Electrophysiology 31, no. 12 (2008): 1554–59. http://dx.doi.org/10.1111/j.1540-8159.2008.01226.x.
Full text
43
Lattimer, Christopher R., Vassilios Zymvragoudakis, George Geroulakos, and Evi Kalodiki. "Venous Thromboprophylaxis With Neuromuscular Stimulation: Is It Calf Muscle Pumping or Just Twitches and Jerks?" Clinical and Applied Thrombosis/Hemostasis 24, no. 3 (2017): 446–51. http://dx.doi.org/10.1177/1076029617726601.
Full textAbstract:
The common peroneal nerve stimulator (CPNS) is a UK–approved device for reducing venous thromboembolism risk. It resembles a wrist watch and is placed over the common peroneal nerve to fire at 1 electrical impulse/sec. The aim was to quantify the claim that it drives the venous muscle pump and imitates walking. Twelve healthy volunteers performed 10 tip-toe maneuvers and 10 ankle dorsiflexions to imitate walking movements. The reductions in calf volume were recorded using air plethysmography (APG). The common peroneal nerve was stimulated for over 10 seconds at each of the 7 increasing electrical impulse settings, and the volume reductions were measured for comparison. The results are expressed as median (interquartile range) absolute (mL), and percentage reduction in calf volume. Tip-toe and dorsiflexion pumping maneuvers were not significantly different: 59 (33.6-96.1), 81.9% vs 51.4 (34-68.5), 59.7%, respectively ( P = .53). However, they both outperformed the CPNS: 10.8 (7.3-18), 13.2% at P = .002 and P = .002, respectively. Qualitatively, the CPNS registered on the tracings as a small spike (muscle twitch) at low settings, with larger amplitudes (ankle jerk) at higher settings. The CPNS activity spikes were discrete, lasting a median (range) of 0.24 (0.16- .3) seconds. The claim that the CPNS empties veins by pumping is supported statistically. However, the amount is small versus the tip-toe and dorsiflexion maneuvers. Furthermore, the CPNS has a short activity profile on the APG trace. Innovations that produce sustained contraction and involve the posterior calf compartments may improve pumping.
44
Lebedev, V. A., and V. V. Polyakov. "Production of finely dispersed titanium powder by volumetric reduction of its ions with sodium dissolved in the BaCl2–CaCl2–NaCl melt." Izvestiya vuzov. Poroshkovaya metallurgiya i funktsional’nye pokrytiya, no. 1 (March 24, 2022): 4–16. http://dx.doi.org/10.17073/1997-308x-2022-1-4-16.
Full textAbstract:
The research is intended to develop a technology for the production of finely dispersed (10 to 100 μm) powders of titanium and its alloys suitable for use in additive technologies after classification and spheroidization. A eutectic mixture was used as electrolyte, mole fractions: BaCl2 – 0.16, CaCl2 – 0.47, NaCl – 0.37, melting point of 452 °C. Electrolytes with a similar composition are used in industry for the electrolytic production of sodium with high current efficiency. No titanium salts were added to electrolyte. Sodium losses due to evaporation, corrosion, and ion recharge were replenished by a periodic increase in electrolysis current. A VT1-0 titanium plate was used as an anode. The walls of a steel crucible served as a cathode. Sodium was released on these walls and dissolved in electrolyte. Titanium ions were reduced in the bulk of electrolyte and in the anode layer. It is the first time that the results obtained were interpreted using the data on the electrode potentials of Ti3+/Ti, Ti2+/Ti, Ti3+/Ti2+ systems. It was shown that the concentration of slowly moving complex Ti3+ ions increases in the anode layer, and sodium dissolved in electrolyte reduces mainly Ti2+ ions in the electrolyte volume in the first 12 min of electrolysis. Starting from the 20th min, the concentration of Ti2+ ions in the anode layer begins to increase rapidly according to the reaction: 2Ti3+ + Ti = 3Ti2+ as titanium powder accumulates in the electrolyte volume. At the same time, the proportion of sodium consumed for the reduction of Ti3+ ions to Ti2+ decreases, which contributes to an increase in current efficiency and cathode potential stabilization for 30 minutes at –2.963 V. After the 50th min, the reactivity of the salt melt begins to decrease, the concentration of Ti3+ ions increases steadily until it levels off with the concentration of Ti2+ ions at the 85th min. This sharply increased the current consumption for ion recharge and made it necessary to stop electrolysis after switching on a current of 12 A for a short time (for 40 s). After 10 s, judging by the change in the cathode potential, sodium dissolved in electrolyte was almost completely consumed for titanium ion reduction. After 6 min, the potentials of electrodes returned to the initial anode potential value indicating that the system returned to its original state with the near-zero content of titanium salts and dissolved sodium. 95 % of powder was obtained in the electrolyte volume. Current efficiency was 84.0 % and turned out to be close to the value calculated from the average valence of titanium ions and the loss of anode weight (87.0 %). After ultrasonic dispersion, more than 80 % of powder was in the 10–100 μm range with a maximum at 36 μm. X-ray phase analysis showed that this is practically pure α-titanium (93.06 %) and oxygenated α-titanium (5.45 %). The originality of the research consists in the use of a volumetric, intensive, electrolytic method for producing finely dispersed titanium powders with no dissolved sodium and titanium chlorides in the initial and final electrolytes, in a stepwise increase in the current and potentiometric process control. The uniqueness of the research consists in the titanium powder obtained where the major part is in the melt volume in the form of intergrowths that are easily crushed by ultrasonic dispersion into individual crystals. Over 80 % of these crystals were in the range of 10–100 μm required for additive technologies with an average size of 36 μm.
45
Ignjatovic, Stefan, Reza Omidi, Rahel A. Kubik-Huch, Suzanne Anderson, and Frank J. Ahlhelm. "The retroneural approach: an alternative technique for lumbar transforaminal epidural steroid injections." Acta Radiologica 59, no. 12 (2018): 1508–16. http://dx.doi.org/10.1177/0284185118762248.
Full textAbstract:
Background Compared with other available injection techniques for lumbar transforaminal epidural steroid injections (LTFESIs), the traditionally performed subpedicular approach is associated with a higher risk of spinal cord infarction, a rare but catastrophic complication. Purpose To assess the short-term efficacy of the retroneural approach for computed tomography (CT)-guided LTFESIs with respect to different needle-tip positions. Material and Methods This retrospective analysis included 238 patients receiving 286 CT-guided LTFESIs from January 2013 to January 2016. Short-term outcomes in terms of pain relief were assessed using the visual analogue scale (VAS) at baseline and 30 min after. The needle-tip location was categorized as extraforaminal, junctional, or foraminal relative to the neural foramen. Additionally, the distance from the needle tip to the nerve root was measured. Results A mean pain reduction of 3.22 points (±2.17 points) on the VAS was achieved. The needle-tip location was extraforaminal in 48% (136/286), junctional in 42% (120/286), and foraminal in 10% (28/286) of the cases. The mean distance from the needle tip to the nerve root was 3.83 mm (±3.37 mm). There was no significant correlation between pain relief and needle-tip position in relation to the neural foramen. Therapy success was not dependent on the distance between the needle tip and the nerve root. No major complications were observed. Conclusion In our population treated with LTFESIs, the retroneural approach was shown to be an effective technique, with no significant differences in pain relief following different needle-tip positions.
46
Rousos, Penelope A., Helen C. Harrison, and Kenneth L. Steffen. "Physiological Responses of Cabbage to Incipient Copper Toxicity." Journal of the American Society for Horticultural Science 114, no. 1 (1989): 149–52. http://dx.doi.org/10.21273/jashs.114.1.149.
Full textAbstract:
Abstract Three-week-old seedlings of the cabbage (Brassica oleracea L. Capitata group) cultivars Wisconsin All Seasons and Globe King were exposed for 3 weeks to Cu2+ concentrations ranging from 1.2 to 2.5 mg Cu2+/liter. Plants were harvested after 14, 16, 19, or 22 days of exposure. During Cu2+ treatment, shoots appeared healthy, but roots turned golden, with increased lateral branching and tip browning. Cultivars responded identically for all characteristics measured. Root Cu concentrations were >3000 μg·g−1 or 300 times the control after Cu2+ treatment. Shoot Cu concentrations (13 μg·g−1), while significantly higher than the control, were not above critical values associated with yield reductions. The high root Cu concentrations were not associated with lower shoot or root yields. The initial symptoms of Cu2+ toxicity in the first fully expanded leaves were elevated leaf Cu concentrations and lower total chlorophyll and chlorophyll a:b ratios. There was no effect on leaf fresh weight per unit area, transpiration, respiration, net photosynthesis, or apparent photosynthetic quantum yields.
47
Won, Tae-Bin, Hong-Ryul Jin, and Hyeon-Jong Lee. "Nasal Tip Surgery in Asians." Otolaryngology–Head and Neck Surgery 139, no. 2_suppl (2008): P31. http://dx.doi.org/10.1016/j.otohns.2008.05.102.
Full textAbstract:
Objective The authors intended to review our surgical techniques used in Asian tip surgery and to suggest effective techniques, according to the types of the nasal tip that are addressed. Methods 107 patients who had nasal tip surgery from Jan. 2005 to Dec. 2006 in a tertiary hospital were enrolled in the study. Medical records, graphic operation records, and standardized patient photographs were retrospectively reviewed. Initial diagnosis, types of nasal tip surgery, associated operative techniques, surgical results and complications were analyzed. Results Initial diagnosis included deviated nose, hump nose, combine deviated and saddle nose, low profile nose, short nose, and cleft nose deformity, in order of frequency. Nasal tip surgery included augmentation of projection, control of rotation, restoration of symmetry and volume reduction, among which augmentation was used in all cases. External approach was used in 74% and intranasal approach in 26%. For augmentation of the tip projection, onlay grafts (39%), septal extension grafts (25%), and tip modifying suture with onlay grafts (20%) were the most commonly used methods. Infection or extrusion of the grafts was not found. Complications included tip deviation due to the deviation of the septal extension graft in 1 case, visible tip graft in 1 case, and slight upward rotation of the tip in 1 case. Conclusions In Asians, augmentation of the tip projection is the main issue in tip surgery and is best performed with cartilage onlay grafts or septal extension graft rather than suture modification.
48
Yang, Woorim, Myung-Hwan Choi, Bosl Noh, and Yoo-Sun Noh. "De Novo Shoot Regeneration Controlled by HEN1 and TCP3/4 in Arabidopsis." Plant and Cell Physiology 61, no. 9 (2020): 1600–1613. http://dx.doi.org/10.1093/pcp/pcaa083.
Full textAbstract:
Abstract Plants have the ability to regenerate whole plant body parts, including shoots and roots, in vitro from callus derived from a variety of tissues. However, the underlying mechanisms for this de novo organogenesis, which is based on the totipotency of callus cells, are poorly understood. Here, we report that a microRNA (miRNA)-mediated posttranscriptional regulation plays an important role in de novo shoot regeneration. We found that mutations in HUA ENHANCER 1 (HEN1), a gene encoding a small RNA methyltransferase, cause cytokinin-related defects in de novo shoot regeneration. A hen1 mutation caused a large reduction in the miRNA319 (miR319) level and a subsequent increase in its known target (TCP3 and TCP4) transcript levels. TCP transcription factors redundantly inhibited shoot regeneration and directly activated the expression of a negative regulator of cytokinin response ARABIDOPSIS THALIANA RESPONSE REGULATOR 16 (ARR16). A tcp4 mutation at least partly rescued the shoot-regeneration defect and derepression of ARR16 in hen1. These findings demonstrate that the miR319-TCP3/4-ARR16 axis controls de novo shoot regeneration by modulating cytokinin responses.
49
Müller, Daniel J., and Andreas Engel. "Structure, Flexibility and Intramolecular Forces Observed on Individual Proteins Using Afm." Microscopy and Microanalysis 5, S2 (1999): 996–97. http://dx.doi.org/10.1017/s1431927600018304.
Full textAbstract:
Atomic force microscopy (AFM) allows the surfaces of native biological macromolecules to be imaged in aqueous solution with submolecular resolution. Short range forces govern the interactions between the AFM tip and the sample and produce the submolecular information of high resolution topographs. In contrast, the long range electrostatic double-layer (EDL) force can be adjusted by pH and electrolytes to distribute the force applied to the AFM tip over a large sample area [1]. As demonstrated on fragile biological samples, adjustment of the electrolyte solution results in a local reduction of both vertical and lateral forces between the AFM tip and proteineous substructures. Consequently, the deformation of the native protein is minimized and polypeptide loops of individual proteins were imaged in aqueous solution with a lateral resolution < 5 Åand a vertical resolution < 1 Å (Fig. 1).
50
Tomita, Kosei, Rinko Akamine, Kazuya Morino, Mami Kusaka, and Masayuki Akimoto. "Short-Term Postoperative Outcome of Baerveldt Glaucoma Implant with Two Tubes Inserted into the Vitreous Cavity." Surgeries 3, no. 4 (2022): 323–33. http://dx.doi.org/10.3390/surgeries3040035.
Full textAbstract:
Here, we report a new surgical technique designed to increase filtration volume and reduce intraocular pressure (IOP) in glaucoma and its one-year outcome. Two tubes were created from a single Baerveldt glaucoma implant (BI) by folding the tube in a U-shape and incising only the outer edge of the stretched loop tip. The tubes were placed into the vitreous cavity via the pars plana through a long scleral tunnel, without a scleral valve or graft patch. Twenty eyes of 18 patients with neovascular glaucoma were included. This technique was performed in 10 eyes of 10 patients (double group), and outcomes were compared to 10 eyes of eight patients in which a single tube BI was inserted (single group). The primary outcome measures included IOP, supplemental medical therapy score (SMTS), and intraoperative and postoperative complications before and after surgery at 12 months. The mean IOP (SMTS) were 32.0 ± 11.33 mmHg (4.1) in the double group and 29.7 ± 6.31 mmHg (5.7) in the single group, preoperatively reduced to 11.8 ± 2.70 mmHg (0.2) (63% reduction, p < 0.004) and 14.2 ± 4.05 mmHg (1.1) (52% reduction, p < 0.002) after 12 months, respectively. SMTS showed 95% (p = 0.005) and 89% (p = 0.005) reductions, respectively. Although there was no significant difference in IOP between the two groups at 12 months (p = 0.16), there were significant differences in the SMTS between the two groups before, and 6 and 12 months after, surgery (p = 0.01, 0.04 and 0.04, respectively). A reduction in the SMTS suggests that increasing filtration volume by placing two tubes has the potential to further reduce IOP as compared with a single tube.