To see the other types of publications on this topic, follow the link: Seedling stress.
Journal articles on the topic 'Seedling stress'
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 'Seedling stress.'
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
Aizen, Marcelo A., and Hilary Woodcock. "Effects of acorn size on seedling survival and growth in Quercus rubra following simulated spring freeze." Canadian Journal of Botany 74, no. 2 (1996): 308–14. http://dx.doi.org/10.1139/b96-037.
Full textAbstract:
Seed size is an important phenotypic trait commonly associated with the fitness of young seedlings exposed to environmental stress. Spring frosts can cause leaf necrosis and seedling mortality in young oak seedlings, and seedling mortality following spring freeze events is a factor limiting the northern range limits of Quercus gambelii (Nutt.). We examined the relationship between acorn size and seedling survival following spring freeze by exposing 1-month-old Quercus rubra (L.) seedlings from two sites in Massachusetts to −3 °C for 8 h. Mortality of 1-month-old frost-exposed seedlings (20–25%) was 10 times higher than control mortality, with survival directly related to acorn size. Seedling size at the end of the first growing season was negatively affected by frost exposure and positively associated with acorn size. Overwintering mortality (<5%) was negatively associated with seedling size. The production of large acorns should confer a selective advantage in habitats susceptible to spring frosts through a positive effect on seedling establishment success under stress. Keywords: red oak, acorn size, frost, seedling survival.
2
Flasiński, Stanisław, Janina Rogozińska, and Lucyna Drozdowska. "The effect of phosphours and water deficit on phosphatase activity and proline accumulation in seedling cotyledons and roots of oilseed rape as compared to that of excised cotyledons and roots." Acta Societatis Botanicorum Poloniae 55, no. 1 (2014): 83–96. http://dx.doi.org/10.5586/asbp.1986.010.
Full textAbstract:
Oilseed rape seedlings and excised cotyledons and roots were exposed to phosphorus and osmotic stress (-1 MPa: NaCl or PEG). The stress factors limited the growth of the seedlings and inhibited the growth of the excised roots and cotyledons. The phosphorus content in the cotyledons and roots depended on its level in the media and on the stress factors used. Phosphorus deficiency differentiated total phosphatase activity in seedling cotyledons and increased the activity in the excised cotyledons. In the excised and seedling roots, the lack of phosphorus, its deficiency and stress imposed by the addition of NaCl, caused an increase in total and specific phosphatase activity. Osmotic stress caused proline accumulation in both the seedling and excised cotyledons, but the effect of phosphorus stress was much smaller. Proline increase in seedling roots followed only after the osmotic stress caused by NaCl. The proline content in the excised roots was low. Stress factors lowered the protein content in the seedling and excised cotyledons. In both seedling and excised roots, the lowering of the protein content occurred mainly in response to osmotic stress. Kinetin modified metabolic responses in seedling cotyledons and roots. The use of in vitro culture allowed the elucidation of the tested responses. In excised cotyledons grown under stress conditions, kinetin increased the phosphorus and protein contents and lowered proline accumulation, suggesting that kinetin had the ability to overcome phosphorus and osmotic stress. The excised oilseed rape roots responded only slightly to kinetin (Drozdowska and Rogozińska 1984) and its effect was much smaller.
3
Jia, Kai, Cunyao Yan, Huizhuan Yan, and Jie Gao. "Physiological Responses of Turnip (Brassica rapa L. subsp. rapa) Seedlings to Salt Stress." HortScience 55, no. 10 (2020): 1567–74. http://dx.doi.org/10.21273/hortsci15187-20.
Full textAbstract:
Turnip (Brassica rapa L. subsp. rapa) is a type of root vegetable belonging to the Brassica subspecies of Cruciferae. Salt stress is one of the main abiotic stresses that causes water deficit, ion toxicity, and metabolic imbalance in plants, seriously limiting plant growth and crop yield. Two commercial turnip cultivars, Wenzhoupancai and Qiamagu, were used to evaluate the seed germination and physiological responses of turnip seedlings to salt stress. NaCl was used to simulate salt stress. Parameters of seed germination, seedling growth, osmoregulation substances content, chlorophyll content, antioxidant enzyme activity, and other physiological parameters of turnip seedlings were measured after 7 days of salt stress. The results showed that salt stress reduced the seed germination rate, and that the seeds of ‘Wenzhoupancai’ were more sensitive to salt stress. Salt stress inhibited the growth of turnip seedlings. With the increased NaCl concentration, the seedling dry weight, seedling fresh weight, and seedling length of turnip decreased gradually. Under the salt stress treatment, the osmotic regulatory substances and antioxidant enzyme activity in the seedlings of turnip increased significantly. The chlorophyll content increased at a lower NaCl level, but it decreased when the level of NaCl was higher. Growth parameters of turnip seedlings had significant negative correlations with the reactive oxygen content, osmoregulation substances, and antioxidant enzyme activities, but they had positive correlations with chlorophyll b and total chlorophyll content. These results indicated that salt stress-induced oxidative stress in turnip is mainly counteracted by enzymatic defense systems.
4
Matusick, G., L. G. Eckhardt, and S. A. Enebak. "Virulence of Leptographium serpens on Longleaf Pine Seedlings Under Varying Soil Moisture Regimes." Plant Disease 92, no. 11 (2008): 1574–76. http://dx.doi.org/10.1094/pdis-92-11-1574.
Full textAbstract:
Recently, Leptographium serpens has been recovered from the roots of declining and dead longleaf pine (Pinus palustris) in stands associated with various abiotic stresses. Although most data suggest that L. serpens is pathogenic to various Pinus spp., there is little known of its virulence on longleaf pine or its relationship with abiotic stress in causing disease. These trials examined the effects of L. serpens infection coupled with drought stress. Trials began with wound inoculations of bareroot longleaf pine seedlings in spring 2006 and 2007 at the seedling stress facility at Auburn University. Soon after inoculation, seedlings were also subjected to adequate moisture, moderate drought, or severe drought. Sixteen weeks after inoculation, longleaf pine survival, L. serpens virulence, and seedling growth characteristics were measured. Longleaf pine seedlings inoculated with L. serpens had 33% mortality (138/420) which was significantly greater than nonwounded control seedlings (22%, 47/211). Survival and lesion size on longleaf pine suggests that L. serpens is moderately pathogenic to longleaf pine seedlings. Separately, moisture stress associated with low soil moisture also contributed to seedling mortality. Results suggest that L. serpens infection and moisture stress commonly experienced by southern pines act independently to stress longleaf pine.
5
Anuradha, S., and S. S. R. Rao. "The effect of brassinosteroids on radish (Raphanus sativus L.) seedlings growing under cadmium stress." Plant, Soil and Environment 53, No. 11 (2008): 465–72. http://dx.doi.org/10.17221/2307-pse.
Full textAbstract:
The effect of 24-epibrassinolide and 28-homobrassinolide on seed germination and seedling growth of radish (<I>Raphanus sativus</I> L.) was studied under cadmium toxicity. The impact of brassinosteroids (BRs) on free proline levels and the activity of antioxidant enzymes catalase (CAT; EC 1.11.1.6), peroxidase (POD; EC 1.11.1.7), superoxide dismutase (SOD; EC 1.15.1.1), ascorbic peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPX; EC 1.11.1.7) in radish seedlings under Cd toxicity was evaluated. The effect of BRs on the activity of ascorbic acid oxidase (AAO; EC 1.10.3.3) and lipid peroxidation in radish seedlings challenged with Cd stress was also investigated. BRs supplementation alleviated the toxic effect of the heavy metal and increased the percentage of seed germination and seedling growth. Out of the two substances, HBL was found to be more effective than EBL in stress alleviation. HBL (3&micro;M) alleviated the toxic effect of the heavy metal and increased the percentage of seed germination by 57% over Cd and 20% over unstressed control. Similarly supplementation of HBL (3&micro;M) caused an increase of 156%, 78% and 91% in length, fresh weight and dry weight of seedling, respectively, over Cd treatment alone. The amelioration of seedling growth by BRs under metal toxicity was associated with enhanced levels of free proline. The activities of antioxidant enzymes CAT, SOD, APOX and GPX were increased in the seedlings from treatments with Cd along with BRs. Brassinosteroid treatment reduced the activity of POD and AAO in heavy metal stressed seedlings. Lipid peroxidation induced by Cd was found reduced with the supplementation of BRs. The results obtained in the study clearly indicated the ameliorative influence of brassinosteroids on the inhibitory effect of Cd toxicity.
6
Ye, Long Hua, Qiu Jing Li, Li Xue, Gan Wen Lie, Xiao Li Hou, and Hong Yue Chen. "Effects of Ozone and Drought on Physiological Characteristics of Three Seedling Types in South China." Applied Mechanics and Materials 522-524 (February 2014): 1089–97. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.1089.
Full textAbstract:
Seedlings of Michelia macclurei, Cinnamomum camphora and Rhodoleiachampionii were placed in open-top chambers (OTC) with two ozonic treatments including E40 (nature air, 40 ppb) and E150 (150 ppb) and two water treatments. Physiological indexes such as chlorophyll, soluble sugar, soluble protein, proline, MDA and SOD of three seedling types were evaluated. With increasing experimental time, chlorophyll content generally decreased or remained steady, soluble sugar content increased followed by a decrease and SOD activity increased for the three seedling types in ozone treatment, drought treatment or ozone-drought intercross treatment. Contents of soluble protein and proline increased for the three seedling types in ozone treatment and drought treatment. The MDA content increased for M. macclurei and C. camphora in ozone treatment and drought treatment and for R. championii in the three stress treatments. Principal component analysis indicated that the resistance abilities of ozone, drought or intercross stress for the three seedling types was C. camphora seedlings > M. macclurei seedlings > R. championii seedlings.
7
Armitage, Allan M. "MINIMIZING ENVIRONMENTAL STRESS IN BEDDING PLANT AND GREENHOUSE PRODUCTION." HortScience 25, no. 9 (1990): 1179c—1179. http://dx.doi.org/10.21273/hortsci.25.9.1179c.
Full textAbstract:
Minimizing environmental stress in bedding plant and greenhouse and seedling development has occupied many researchers in academia and industry for many years. The dependence on single plant germination units (plugs) for bedding plant production and high value hybrid seed demand high rates of germination and successful seedling establishment. Pre-germinating or priming of seed is an important method of germination enhancement and methods and benefits of “priming” will be discussed. Environmental options to enhance seed germination of non-primed seed include control of vapor pressure deficit (VPD) and temperature.Enhancement of seedling establishment through growth room and greenhouse technology includes the optimal use of CO2, temperature and light. Carbon dioxide fertilization on seedlings is receiving serious study and will be further elucidated.
8
Cobb, B. G., D. L. Andrews, D. M. MacAlpine, J. R. Johnson, and M. C. Drew. "1001 ANOXIA TOLERANCE OF MAIZE SEEDLING ROOTS." HortScience 29, no. 5 (1994): 573a—573. http://dx.doi.org/10.21273/hortsci.29.5.573a.
Full textAbstract:
We have been examining the response of maize seedling roots to oxygen stress. Previously, we have shown that maize seedlings with primary root lengths of 10cm or greater require a pretreatment with low oxygen (hypoxia) for survival of greater than 12 hours of anoxia. During the pretreatment there is induction of mRNA and increase in enzymatic activity of alcohol dehydrogenase (ADH) and other enzymes that are necessary for alcoholic fermentation. However, we have found that younger seedlings do not need a pretreatment to survive anoxia. They appear to have high levels of ADH and other enzymes that are needed for anaerobic survival at levels equivalent to those that are induced in older seedlings. These results suggest that, at the time of seedling emergence, seedlings may be more adapted to oxygen stress than during later stages of growth.
9
Battaglia, M., and JB Reid. "The Effect of Microsite Variation on Seed-Germination and Seedling Survival of Eucalyptus delegatensis." Australian Journal of Botany 41, no. 2 (1993): 169. http://dx.doi.org/10.1071/bt9930169.
Full textAbstract:
The correlation between microsite and seedling numbers was determined in field sowings, and the impact of microsites on germination and seedling survival tested in artificial seedbeds in the glasshouse. Small scale variation in soil conditions, at the scale of tens of centimetres, markedly affected the germination and establishment of Eucalyptus delegatensis R.T.Baker seeds and seedlings. Under conditions of limiting soil moisture, microsites that afforded protection, and probably resulted in increased humidity, caused a marked increase in germination number and rate. The mean survival time was significantly higher on these protected microsites than on less protected microsites, or on microsites that restricted root penetration. The importance of this variability in microtopography was strongly influenced by season and the level of environmental stress, and was diminished as seedlings aged. Due to the different requirements for seed germination and seedling growth, a favourable microsite for germination was not necessarily a favourable site for seedling survival. A comparison of seed and seedling responses to water stress indicated that for E. delegatensis, at least, selection due to microsite differences at the time of germination may not have an impact on the developmental characteristics of the seedlings.
10
Singh, N. B., and Nimisha Amist. "Interactive Effects of Cinnamic Acid and Water Stress on Wheat Seedlings." INTERNATIONAL JOURNAL OF PLANT AND ENVIRONMENT 4, no. 01 (2018): 105–12. http://dx.doi.org/10.18811/ijpen.v4i01.11616.
Full textAbstract:
In the present study we compared the effects of allelochemical with water stress (WS) on growth, biochemical parameters and responses of antioxidative enzymes in wheat seedlings. The wheat seedlings were treated with 0.5, 1.0 and 1.5 mM concentrations of cinnamic acid (CA) with and without water stress by withholding water supply for 5 days. Leaf water status, photosynthetic pigments, protein content, amount of proline and nitrate reductase (NR) and antioxidant enzymes activities were examined. CA resulted in reduction of seedling height with drastic decrease in stressed seedlings. The combined treatments CA+WS further decreased the seedling height. The same result was registered for seedlings dry weight, relative water content and pigment and protein contents. Total soluble sugar content and nitrate reductase activity were variedly affected under all treatments. Proline content and lipid peroxidation increased. Activity of superoxide dismutase increased significantly (less than 0.05) while catalase P activity was lower in all treatments. Ascorbate peroxidase and guaiacol peroxidase activities were higher as compared with catalase which showed protection of wheat seedlings from oxidative stress. Water stress elevated the toxic effect of allelochemical.
11
Machado Neto, Nelson Barbosa, Sérgio Marques Saturnino, Daniel Carlini Bomfim, and Ceci Castilho Custódio. "Water stress induced by mannitol and sodium chloride in soybean cultivars." Brazilian Archives of Biology and Technology 47, no. 4 (2004): 521–29. http://dx.doi.org/10.1590/s1516-89132004000400004.
Full textAbstract:
Four soybean (Glycine max L. Merril.) cultivars were contrasted in relation to germination and vigour of seedlings, when seeds were submitted to water stress induced by mannitol or sodium chloride. Water stress affected seed germination and seedling development, however, seedling development was affect in higher osmotic potential (-0.3MPa) than the necessary to affect germination -1.2MPa when induced by mannitol or -0.6MPa when induced by sodium chloride. 'Pioneira' and 'Xingu' cultivars had high development in low water availability and/or salinity conditions.
12
Montville, Mark E., David L. Wenny, and R. Kasten Dumroese. "Foliar Fertilization During Bud Initiation Improves Container-Grown Ponderosa Pine Seedling Viability." Western Journal of Applied Forestry 11, no. 4 (1996): 114–19. http://dx.doi.org/10.1093/wjaf/11.4.114.
Full textAbstract:
Abstract Our objective was to determine if avoiding nutrient stress during bud initiation of ponderosa pine (Pinus ponderosa vat. ponderosa) grown in a container nursery would enhance seedling viability. Nitrogen stress was avoided by applying foliar fertilizer at rates between 324 and 972 ppm N to greenhouse-grown seedlings. Foliar fertilization maintained higher seedling nitrogen levels and increased root collar diameter by 45%. Height was slightly increased, cold-hardiness slightly reduced, and root growth potential unaffected by foliar fertilizer applications. Nursery managers can improve seedling viability by adding foliar fertilizer applications to their growing regimes. West. J. Appl. For. 11(4):114-119.
13
Chakma, Shyama Prashad, Stephen Mushimwa Chileshe, Richard Thomas, and Priti Krishna. "Cotton Seed Priming with Brassinosteroid Promotes Germination and Seedling Growth." Agronomy 11, no. 3 (2021): 566. http://dx.doi.org/10.3390/agronomy11030566.
Full textAbstract:
Cotton (Gossypium hirsutum) is the largest fibre crop globally and an important oilseed crop. Rising temperatures and declining water supplies, which are also impacting soil salinity, threaten cotton plant productivity. Germination, emergence and young seedling stages in cotton are highly sensitive to salinity and heat stresses. Brassinosteroids (BRs) are plant steroid hormones that are essential for proper plant growth and development and also promote tolerance to a range of environmental stresses. Cotton seeds were primed with BR (24-epibrassinolide) alone or in combination with other hormones (abscisic acid, auxin and gibberellic acid) and tested for germination and early seedling growth. BR promoted germination under no stress as well as under salinity and heat stress conditions, while other hormones were ineffective under stress conditions. BR also promoted cotyledon opening and the development of lateral roots in germinated seedlings. The ability of BR to positively impact seedling growth across different stress conditions suggests that priming cotton seeds with BR may help in early and successful establishment of seedlings, which may benefit the plant through its lifecycle.
14
Rietveld, W. J. "Transplanting Stress in Bareroot Conifer Seedlings: Its Development and Progression to Establishment." Northern Journal of Applied Forestry 6, no. 3 (1989): 99–107. http://dx.doi.org/10.1093/njaf/6.3.99.
Full textAbstract:
Abstract Transplanting stress is: (1) a temporary condition of distress from injuries, depletion, and impaired functions; (2) a process of recovery; and (3) a period of adjustment to a new environment. Some transplanting stress is unavoidable, even with good stock in a favorable environment. The degree and duration of stress depend on the interactions of seedling performance potential and the site environment. Renewal of root-to-soil contact is important for resumption of adequate water and nutrient uptake. Root growth is sensitive to soil temperature and plant moisture stress. If reserve carbohydrates are exhausted before they are replenished from photosynthesis, the seedlings may die. Preplant handling and postplant drought aggravate transplanting stress. Stress can be minimized by planting stock with high stress resistance, preserving seedling performance potential, preparing a favorable planting site environment, and planting the seedlings properly. North. J. Appl. For. 6:99-107, September 1989
15
Mandic, V., V. Krnjaja, Z. Bijelic, et al. "Genetic variability of red clover seedlings in relation to salt stress." Biotehnologija u stocarstvu 30, no. 3 (2014): 529–38. http://dx.doi.org/10.2298/bah1403529m.
Full textAbstract:
Red clover is highly salt-sensitive plant, especially during germination and early seedling growth stages. The aim of this investigation was to estimate the effects of different saline conditions (0, 50, 100, 150, and 200mM NaCl) on germination and early seedling growth in four red clover varieties (Kolubara, K-32, K-17 and K-39). Germination test was conducted in the laboratory conditions using sterile plastic vessels on filter paper moistened with 10ml of the appropriate salt test solutions. It was observed that the germination energy (GE), germination (G), percentage of dead or infected seeds (DIS), normal seedlings (NS), root length (RL), shoot length (ShL), fresh weight (FW) and dry weight of seedling (DW) and seedling vigor index (SVI) were significantly decreased with increasing concentrations of NaCl in the growing medium. The tested varieties of red clover showed different NaCl tolerance at the seedling stage. Generally, studied red clover varieties are very sensitive to salt, especially K-32 which has the lowest values for GE, G, NS and SVI and highest for DIS. Variety K-17 proved to be a variety that the best tolerates conditions of salt stress because the values for GE, G, NS, RL and SVI were highest. Testing of varieties of red clover in the early seedling growth at different concentrations of NaCl in the growing medium could be helpful in the identification and selection of varieties for cultivation on saline soils.
16
Couvillon, Gary A. "Cercis canadensis L. Seed Size Influences Germination Rate, Seedling Dry Matter, and Seedling Leaf Area." HortScience 37, no. 1 (2002): 206–7. http://dx.doi.org/10.21273/hortsci.37.1.206.
Full textAbstract:
Several studies with annual crops have shown that large seeds improve percent germination, seedling growth, and uniformity, yield, seedling vigor, and stress tolerance. Little information is available on the influence of seed size on the resulting seedlings of woody plant species. Cercis canadensis L. seeds were divided into large and small seed size fractions and the seeds scarified, stratified, and planted. A larger percentage of large seeds germinated than did small seeds. Seedlings from large seeds had a greater peak and germination value than small seeds, indicating greater vigor and a more rapid germination rate thus more uniform seedlings. Seedlings from large seeds, as indicated by fresh and dry weights, were larger and contained a greater leaf area than those produced by small seed.
17
South, David B. "Needle-Clipping Longleaf Pine and Top-Pruning Loblolly Pine in Bareroot Nurseries." Southern Journal of Applied Forestry 22, no. 4 (1998): 235–40. http://dx.doi.org/10.1093/sjaf/22.4.235.
Full textAbstract:
Abstract Studies have shown that clipping needles of longleaf pine before outplanting can increase average seedling survival by 13 percentage points. Under some situations, the increase in survival might be due to a reduction in transpiration. For loblolly pine, top-pruning in the nursery might increase average survival by 6 percentage points. Benefits of pruning appear greater when seedlings experience stress after planting and when nonpruned seedlings have low root weight ratios (root dry weight/total seedling dry weight). On some droughty sites, a seedling with a 0.3 root weight ratio might have an 80% chance of survival, while a seedling with a 0.2 root weight ratio might only have a 53% chance of survival. In most studies where heights were measured after 3 yr in the field, pruned seedlings were the same height as nonpruned seedlings (± 7 cm). South. J. Appl. For. 22(4):235-240.
18
Becker, C. A., G. D. Mroz, and L. G. Fuller. "The effects of plant moisture stress on red pine (Pinusresinosa) seedling growth and establishment." Canadian Journal of Forest Research 17, no. 8 (1987): 813–20. http://dx.doi.org/10.1139/x87-129.
Full textAbstract:
Red pine (Pinusresinosa Ait.) 2-0 and 3-0 bare-root and 1-0 containerized seedlings were subjected to five different watering regimes (drying cycles). Overall, moisture stress as measured with a pressure bomb was highly correlated with seedling growth and survival. While shoot elongation during the drought period was unaffected, stressed seedlings showed pronounced decreases in cambial activity, secondary needle elongation, subsequent bud formation, root length, and number of active mycorrhizal root tips per centimetre compared with control treatments. This resulted in reduced top and root dry-matter production. Watering treatments with average seasonal internal moisture stress values in the range of −8 to −11 bar (1 bar = 100 kPa) showed no measurable reductions in seedling growth. Consistently, less internal moisture stress in the containerized seedlings indicate they are better able to avoid drought. Overall, performance of the 2-0 bare-root seedlings was superior to that of the 3-0 and containerized stock.
19
Korkmaz, Ahmet, and Robert J. Dufault. "Developmental Consequences of Cold Temperature Stress at Transplanting on Seedling and Field Growth and Yield. I. Watermelon." Journal of the American Society for Horticultural Science 126, no. 4 (2001): 404–9. http://dx.doi.org/10.21273/jashs.126.4.404.
Full textAbstract:
Watermelon (Citrullus lanatus (Thunb.) Matsum. and Nakai) seedlings transplanted before the last frost date may be exposed to temperatures alternating between freezing and optimal until field temperatures finally stabilize. Cold stress may ultimately reduce growth and yield. To simulate such temperature alternations that occur naturally after field transplanting, diploid `Carnival' watermelon seedlings were exposed immediately before field planting to cyclic cold temperature stress at 2 ± 1 °C then transferred to a greenhouse at 29 ± 5 °C. In 1997, transplants were exposed to 2 °C from 3 to 81 hours and in 1998, exposure ranged from 9 to 81 hours. Cold-stressed seedlings were field planted after all potential risk of cold stress in the field had passed. In 1997, cold stress decreased seedling shoot and root fresh and dry weights, leaf area, chlorophyll and carbohydrate contents but not seedling height. In 1998, all seedling growth variables decreased in response to longer durations of cold stress. Plants cold stressed for up to 81 hours transpired more for 1 week after transplanting than those exposed to shorter periods of cold stress. In both years, vining (date first runner touched the ground), flowering, and fruit set were delayed significantly as cold stress hours increased. Although early yields were unaffected, total yields decreased linearly in both years with increasing hours of cold, with 38 to 40 hours of cold stress reducing yield 10% in both years. Data indicate that `Carnival' watermelon transplants exposed to cold stress soon after transplanting may suffer yield reductions.
20
Nguyen, Chi D., Jianjun Chen, David Clark, Hector Perez, and Heqiang (Alfred) Huo. "Effects of Maternal Environment on Seed Germination and Seedling Vigor of Petunia × hybrida under Different Abiotic Stresses." Plants 10, no. 3 (2021): 581. http://dx.doi.org/10.3390/plants10030581.
Full textAbstract:
Seed germination and seedling vigor can be affected by environmental cues experienced by the mother plant. However, information about how the maternal environment affects seed quality is scarce in ornamental plants. This study aimed to investigate the effects of two different maternal environments on the seed germination and seedling vigor of Petunia × hybrida under a variety of abiotic stresses. Petunia mother plants were grown in either a greenhouse during the summer months or an indoor controlled-temperature-and-light environment. Collected seeds were subjected to external stressors, including polyethylene glycol (PEG), sodium chloride (NaCl), high temperature, and abscisic acid (ABA), to determine seed germination percentage and seedling vigor. Results indicated that seeds harvested from the mother plants grown in a controlled environment germinated better than seeds harvested from the mother plants grown in the greenhouse when suboptimal germination conditions were applied. Additionally, the seedlings from the controlled maternal environment performed better in both ABA and salinity stress tests than the greenhouse seedlings. Interestingly, the greenhouse seedlings displayed less reactive oxygen species (ROS) damage and lower electrolyte leakage than the controlled environment seedlings under dehydration stress. The difference in germination and seedling vigor of seeds from the two different maternal environments might be due to the epigenetic memory inherited from the mother plants. This study highlighted the strong impact of the maternal environment on seed germination and seedling vigor in Petunia and may assist in high-quality seed production in ornamental plants.
21
SAYYARI, Mohammad, Fardin GHANBARI, Sajad FATAHI, and Fatemeh BAVANDPOUR. "Chilling Tolerance Improving of Watermelon Seedling by Salicylic Acid Seed and Foliar Application." Notulae Scientia Biologicae 5, no. 1 (2013): 67–73. http://dx.doi.org/10.15835/nsb518293.
Full textAbstract:
Chilling temperatures lead to numerous physiological disturbances in the cells of chilling-sensitive plants and result in chilling injury and death of tropical and subtropical plants such as watermelon. In this study, the possibility of cold stress tolerance enhancing of watermelon seedling (Citrullus lanatus) by exogenous application of Salicylic acid (SA) was investigated. SA was applied through seed soaking or foliar spray at 0, 0.5, 1 and 1.5 mM concentration. After SA treatment, the seedlings were subjected to chilling 5 h/day at 4°C for 5 days. Statistical analysis showed significant effects of the application methods and SA concentrations on plant growth parameters, photosynthetic pigments, electrolyte leakage, proline and chilling injury index. SA application improved growth parameters and increased chlorophyll content of watermelon seedling subjected to chilling stress and provided significant protection against chilling stress compared to non-SA-treated seedlings. Although two SA application methods improved chilling stress tolerance, seed soaking method provided better protection compared to foliar spray method. SA ameliorated the injury caused by chilling stress via inhibiting proline accumulation and leaf electrolyte leakage. The highest cold tolerance was obtained with 0.5 mM SA application. Results indicate that SA could be used effectively to protect watermelon seedling from damaging effects of chilling stress at the early stages of growth.
22
MacDonald, Joanne E., and John N. Owens. "Morphology, Physiology, Survival, and Field Performance of Containerized Coastal Douglas Fir Seedlings Given Different Dormancy-induction Regimes." HortScience 41, no. 6 (2006): 1416–20. http://dx.doi.org/10.21273/hortsci.41.6.1416.
Full textAbstract:
The effects of different dormancy-induction regimes on first-year containerized coastal Douglas fir [Pseudotsuga menziesii (Mirb.) Franco var. menziesii] seedling morphology and physiology in the nursery, as well as seedling survival and performance after one growing season in a common garden, were investigated. In early July, three dormancy-induction regimes were applied: moderate moisture stress (MS), short day (SD), and short day with moderate moisture stress (SD+MS). In early October, seedling height, root collar diameter, and shoot dry weight were unaffected by regime, but root dry weight was reduced in seedlings from the MS and SD+MS regimes compared with the SD regime. At this time, morphogenesis was completed in all terminal buds of seedlings from both SD regimes, whereas it continued in all terminal buds of seedlings from the MS regime. Furthermore, 25% to 88% of terminal buds from the SD regimes were endodormant, but none from the MS regime were endodormant. In March, budbreak occurred at the same time in seedlings from the two SD regimes and was earlier than in seedlings from the MS regime; root growth capacity was unaffected by regime. After one growing season, there were no regime differences in seedling survival, root collar diameter, shoot dry weight, root dry weight, length of the current-year leader, or number of needles on the leader.
23
Groninger, J. W., J. R. Seiler, S. M. Zedaker, and P. C. Berrang. "Photosynthetic response of loblolly pine and sweetgum seedling stands to elevated carbon dioxide, water stress, and nitrogen level." Canadian Journal of Forest Research 26, no. 1 (1996): 95–102. http://dx.doi.org/10.1139/x26-010.
Full textAbstract:
Seedling stands of loblolly pine (Pinustaeda L.) and sweetgum (Liquidambarstyraciflua L.) were grown in monoculture or mixed stands for two growing cycles in controlled-environment chambers. Treatments consisted of ambient (408 ppm) and elevated (806 ppm) CO2, concentrations, water-stressed and well-watered conditions, and low (20 kg N/ha) and high (215 kg N/ha) nitrogen application rates. Photosynthesis rates were measured under ambient and elevated cuvette CO2 concentrations for both whole stands and individual seedlings from these stands. Significant interactions between CO2 and water suggested that elevated CO2 concentration compensated for low water availability in individually measured loblolly pine and in whole seedling stands regardless of stand type. Expressing photosynthesis on a soil area versus a leaf-mass basis influenced the photosynthetic rankings of the three stand types relative to one another. Net photosynthetic rates per unit leaf mass were 390 and 880% higher in individually measured seedlings than in whole monoculture stands for loblolly pine and sweetgum, respectively. Lower photosynthetic contributions from lower canopy leaves in whole seedling stands compared with the upper canopy leaves used in individual-seedling measurements were thought to be responsible for lower photosynthetic rates in seedling stands. These results suggest that photosynthetic response is influenced by canopy dynamics that are unaccounted for by individual-seedling measurements of photosynthesis. Differences in photosynthetic response between loblolly pine and sweetgum stands and individuals are thought to be largely due to species-specific differences in canopy light extinction characteristics.
24
Cao, Haobing, Zhenchang Zhu, Rebecca James, et al. "Wave effects on seedling establishment of three pioneer marsh species: survival, morphology and biomechanics." Annals of Botany 125, no. 2 (2019): 345–52. http://dx.doi.org/10.1093/aob/mcz136.
Full textAbstract:
Abstract Background and Aims It is important to have an in-depth mechanistic understanding of tidal marsh establishment and dynamics to ensure the long-term persistence of these valuable ecosystems. As wave forcing may be expected to impact seedling establishment, we studied the effect of water-imposed drag forces on seedling survival, morphology and biomechanical properties of three marsh pioneer species that are dominant along the salinity gradient in many areas around the world: Spartina anglica (salt to brackish), Scirpus maritimus (brackish) and Phragmites australis (brackish to fresh). Methods Using a newly developed plant-shaking mesocosm (PSM) that mimicked water-imposed wave drag forces, the effect of wave stress on seedling survival was examined, together with impacts on morphology and biomechanical properties. Key Results After 7 weeks of exposure to wave stress, lowered seedling survival and growth for all species was revealed. Wave treatments increased the root/shoot biomass ratio to enhance anchorage and made seedlings more flexible (i.e. reduced flexural rigidity), which might be regarded as a mixed outcome between a stress avoidance and stress tolerance strategy. Conclusions The different biomechanical responses between the three dominant marsh pioneer species, overall, make them less resistant to external stress. Therefore, our results indicate that the likelihood of marshes becoming established is reduced if wave energy increases. Despite the different biomechanical response of these three pioneer species to waves, the seedlings of all species were found to have low resistance to external stresses.
25
Yuan, Zhiheng, Chuntian Wang, ShiPeng Li, Xiao Li, and Fuju Tai. "Effects of different plant hormones or PEG seed soaking on maize resistance to drought stress." Canadian Journal of Plant Science 94, no. 8 (2014): 1491–99. http://dx.doi.org/10.4141/cjps-2014-110.
Full textAbstract:
Yuan, Z., Wang, C., Li, S., Li, X. and Tai, F. 2014. Effects of different plant hormones or PEG seed soaking on maize resistance to drought stress. Can. J. Plant Sci. 94: 1491–1499. Drought stress has a major impact on plant growth and productivity, and seed soaking is an important way to increase seedling resistance to drought stress. This study investigated whether drought hardening chemicals, such as polyethylene glycol (PEG), or plant growth regulators enhance plant drought tolerance. The effects of PEG and several plant hormones, such as indoleacetic acid, gibberellic acid 3, 6-benzylaminopurine (6-BA), on seed germination and seedling growth under drought stress were analyzed. The results revealed that seed soaking with 5×10−3 mg L−1 6-BA or 10% PEG improved maize seed germination parameters under drought stress, including seedlings dry weight, seed vigor and germination rate. In addition, some physiological indices, such as superoxide dismutase and catalase activities, soluble protein contents and malondialdehyde etc. in seedlings under drought stress were improved compared with the control. Therefore, the application of 6-BA or PEG as a seed soak treatment had a significant and synergistic effect on seed germination and seedling growth under drought stress. However, the PEG seed soak treatment maybe slightly lead to plant damage and then improved plant ability to acquire some resistance to stress, the 6-BA were not so.
26
Liptay, A. "Air circulation in growth chambers stunts tomato seedling growth." Canadian Journal of Plant Science 72, no. 4 (1992): 1275–81. http://dx.doi.org/10.4141/cjps92-161.
Full textAbstract:
Air circulation, generally an integral part of environmentally controlled plant growth chambers, inhibited tomato (Lycopersicon esculentum Mill.) seedling growth seismomorphogenically. Tomato seedlings were grown either in a growth chamber having an air movement of 0.5–0.7 m s−1 or in a chamber with no air circulation. Growth inhibition was noticeable with as little as 15 min of daily exposure to air circulation, and a continuous exposure gave the greatest amount of growth inhibition. The air-movement effect on seedling growth was transient and required a continued daily exposure to air movement for growth inhibition. Continuous air circulation inhibited seedling growth to such an extent that in a two-factor experiment (i.e., air movement and water stress) the water-stress effects were completely hidden by the air-movement effect. The results have important implications for tomato plant growth experiments in chambers equipped with air circulation: seedling growth may be affected more by the inherent air circulation in the growth chamber than by an experimental treatment.Key words: Tomato growth inhibition, air movement, seismomorphogenic, short seedlings
27
NICOLAU, JOSEFA PATRÍCIA BALDUINO, FRANCISCO EUDES DA SILVA, FRANCIVAL CARDOSO FELIX, SALVADOR BARROS TORRES, MAURO VASCONCELOS PACHECO, and MÁRCIO DIAS PEREIRA. "DISCONTINUOUS HYDRATION ON THE GERMINATION OF Mimosa caesalpiniifolia AND Pityrocarpa moniliformis SEEDS UNDER WATER STRESS." Revista Caatinga 33, no. 2 (2020): 555–61. http://dx.doi.org/10.1590/1983-21252020v33n228rc.
Full textAbstract:
ABSTRACT The use of discontinuous hydration cycles can act in improving seed germination and seedling initial growth under water stress. In this context, the objective of this study was to evaluate the effect of discontinuous hydration on the germination of Mimosa caesalpiniifolia and Pityrocarpa moniliformis seeds under water stress. For this, seeds of these species were subjected to 0 (without hydration), 2 and 4 hydration cycles (18 h) and dehydration (12 and 18 h, respectively), with subsequent germination under water stress simulated for osmotic potentials of 0.0 (distilled water), -0.2, -0.4, -0.6 and -0.8 MPa. Seedlings were evaluated using tests of germination, germination speed index, mean germination time and seedling length. Discontinuous hydration in M. caesalpiniifolia and P. moniliformis seeds hampers germination and vigor of seedlings under water stress up to -0.6 MPa. However, the use of two cycles in P. moniliformis favors germination under more severe water stress (-0.8 MPa).
28
Nandhini, D. Udhaya, and E. Somasundaram. "Effects of rhizobial nod factors (Lipo chitooligosaccharide) on seedling growth of maize (Zea mays L.) under salt stress." Bangladesh Journal of Botany 47, no. 4 (2018): 831–37. http://dx.doi.org/10.3329/bjb.v47i4.47359.
Full textAbstract:
Effects of nod factors (lipo chitooligosaccharide) on seedling growth of maize under salt stress have been studied. The study was framed with seed priming using lipo chitooligosaccharide (LCO) a nod factor @ 4 ml/kg of seeds and without priming on maize seedling growth which was exposed to different levels of salinity (0, 2, 4, 6, 8 and 10 dS/m). Salinity negatively influenced the seedling growth of maize. However nod factor treated maize seedlings had relatively higher germination percentage, root length, shoot length, reducing sugars and amylase activity. Correlation analysis revealed positive relationships between seedling growth parameters. Thus, seed priming with nod factor (4 ml/kg) improved the resistance to salinity at seedling stage. NaCl concentrations restricted amylase enzyme activity and reducing sugar content in the germinating seeds. Priming of nod factor/LCO mitigated the restricted effects of salinity on amylase activity and reducing sugars.
29
Petrovic, Gordana, Dusica Jovicic, Zorica Nikolic, et al. "Comparative study of drought and salt stress effects on germination and seedling growth of pea." Genetika 48, no. 1 (2016): 373–81. http://dx.doi.org/10.2298/gensr1601373p.
Full textAbstract:
Seed germination is first critical and the most sensitive stage in the life cycle of plants compromise the seedlings establishment. Salt and drought tolerance testing in initial stages of plant development is of vital importance, because the seed with more rapid germination under salt or water deficit conditions may be expected to achieve a rapid seedling establishment, resulting in higher yields. The aim of this study was to determine whether the pea seed germination and seedling growth were inhibited by the salt toxicity and osmotic effect during the seedling development, and also identification of the sensitive seedling growth parameters in response to those stresses. Based on the obtained results, pea has been presented to be more tolerant to salt than water stress during germination and early embryo growth. Investigated cultivars showed greater susceptibility to both abiotic stresses when it comes growth parameters compared to seed germination.
30
Morgan, JW. "Ecological Studies of the Endangered Rutidosis leptorrhynchoides. II. Patterns of Seedling Emergence and Survival in a Native Grassland." Australian Journal of Botany 43, no. 1 (1995): 13. http://dx.doi.org/10.1071/bt9950013.
Full textAbstract:
The emergence, survival and growth of seedlings of the endangered Rutidosis leptorrhynchoides F.Muell. were followed in a Themeda triandra grassland during 1991 and 1992. The effect of summer irrigation on seedling survival was also investigated. Seedling emergence occurred in both years within 2 weeks of the 'autumn break' when soil moisture rose above 20%. Ninety percent of emergence was observed within 4 weeks of the onset of germination and 87% of seedlings were within 20 cm of an established plant. No emergence was observed after 8 weeks. Thirteen percent of the 1991 cohort survived for 14 months. Mortality of most seedlings (63%) was attributed to soil moisture stress in summer. Small seedlings (Ͱ4 3 leaves) were no more susceptible to drought than larger seedlings. Seventy two percent of the 1991 cohort produced four leaves before subsequently dying. In 1992, however, most early seedling mortality was amongst cotyledonary seedlings. No seedlings flowered in their first year. Above-ground growth was slow and by 14 months, 60% of surviving seedlings had seven or fewer live leaves. Irrigation in a year of below-average rainfall had no significant effect on the survival and growth of seedlings. This suggests that seedling recruitment is not restricted to climatically favourable years (i.e. is not episodic) but rather, is potentially on-going provided suitable microsites are available for seedling survival.
31
Margolis, Hank A., and David G. Brand. "An ecophysiological basis for understanding plantation establishment." Canadian Journal of Forest Research 20, no. 4 (1990): 375–90. http://dx.doi.org/10.1139/x90-056.
Full textAbstract:
Forest plantations in the early stages of establishment are considered as hierarchical biological systems, and some implications for the design of research projects and the education of regeneration foresters and scientists are discussed. Since less than optimum environmental conditions convey stress to seedlings, seedlings will in turn exhibit a strain response at either the biochemical, physiological, or morphological level. Environmental conditions in a clear-cut are contrasted with other regeneration niches, and implications for the performance of different plantation species are discussed. The important physiological and biochemical limitations on the absorption of water, nitrogen, and carbon by seedlings during their establishment phase are described. Methods of quantifying stress at the plantation site, including simple ways to separate seedling growth into its different physiological components, are shown. An example of an eastern white pine (Pinusstrobus L.) plantation grown under different levels of soil temperature, fertilization, and brush control is presented to illustrate the concepts. An approach to silvicultural research is proposed that determines the effects of silvicultural treatment on the seedling environment and then relates these environmental conditions to seedling biochemistry, physiology, and growth.
32
Cheng, C., L. M. Pei, T. T. Yin, and K. W. Zhang. "Seed treatment with glycine betaine enhances tolerance of cotton to chilling stress." Journal of Agricultural Science 156, no. 3 (2018): 323–32. http://dx.doi.org/10.1017/s0021859618000278.
Full textAbstract:
AbstractChilling injury is an important natural stress that can threaten cotton production, especially at the sowing and seedling stages in early spring. It is therefore important for cotton production to improve chilling tolerance at these stages. The current work examines the potential for glycine betaine (GB) treatment of seeds to increase the chilling tolerance of cotton at the seedling stage. Germination under cold stress was increased significantly by GB treatment. Under low temperature, the leaves of seedlings from treated seeds exhibited a higher net photosynthetic rate (PN), higher antioxidant enzyme activity including superoxide dismutase, ascorbate peroxidase and catalase, lower hydrogen peroxide (H2O2) content and less damage to the cell membrane. Enzyme activity was correlated negatively with H2O2 content and degree of damage to the cell membrane but correlated positively with GB content. The experimental results suggested that although GB was only used to treat cotton seed, the beneficial effect caused by the preliminary treatment of GB could play a significant role during germination that persisted to at least the four-leaf seedling stage. Therefore, it is crucial that this method is employed in agricultural production to improve chilling resistance in the seedling stage by soaking the seeds in GB.
33
TOUNEKTI, Taieb, Mosbah MAHDHI, Zarraq AL-FAIFI, and Habib KHEMIRA. "Priming improves germination and seed reserve utilization, growth, antioxidant responses and membrane stability at early seedling stage of Saudi sorghum varieties under drought stress." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 48, no. 2 (2020): 938–53. http://dx.doi.org/10.15835/nbha48211841.
Full textAbstract:
Seeds of three sorghum (Sorghum bicolor (L.) Moench.) varieties from Southwest Saudi Arabia were used to investigate the potential of osmopriming with polyethylene glycol (PEG 8000) to improve germination performance, seed reserve utilization and early seedling growth and drought stress tolerance. The primed (PS) and unprimed (UPS) seeds of the three sorghum varieties were germinated for 8 days under increasing PEG-induced osmotic stress. The treatments were arranged in a completely randomized design, in a factorial arrangement, with three sorghum cultivars (‘Zaydia’, ‘Shahbi’ and ‘Ahmar’) and four osmotic potentials (0.0; -0.4; -0.8 and -1.2 MPa) with four replicates of 50 seeds each. The results showed that drought stress affected seed germination and seedling emergence and establishment, but increased the activity of the antioxidant enzyme catalase (CAT). The strongest inhibition of germination and growth occurred at the highest PEG concentration and a significant difference was noticeable between the studied varieties. We confirmed also that seed osmopriming improved seed germination performance, seedling growth and enhanced the CAT activities while reduced malonyldialdehyde (MDA) accumulation and electrolyte leakage (EL) in the drought-stressed seedlings. Seed priming have enhanced also the α-amylase and total proteases activities in all varieties. The largest increase of these hydrolysing enzymes was shown in ‘Ahmar’. Furthermore, the PEG priming lead to improvement of the weight of utilized (mobilized) seed reserve (WUSR), seed reserve depletion percentage (SRDP) and total seedling dry weight (SLDW) of sorghum seedlings under water stress conditions. Still, the highest values or all three parameters were found in the ‘Ahmar’ variety. Under increasing drought stress conditions, ‘Ahmar’ showed the highest yield stability index (YSI) and the least EL and MDA contents in comparison to the other two varieties during the seedling establishment stage. Therefore, the former variety can tolerate better a rigorous water stress condition. ‘Zaydia’ appears to be the most vulnerable to drought stress. Thus, the use of species or varieties with eminent seed metabolic quality is an advantageous trait in drought-prone regions.
34
Geballe, Gordon T., William H. Smith, and Philip M. Wargo. "Red spruce seedling health: an assessment of acid fog deposition and heavy metal soil contamination as interactive stress factors." Canadian Journal of Forest Research 20, no. 10 (1990): 1680–83. http://dx.doi.org/10.1139/x90-222.
Full textAbstract:
Two-year-old spruce (Picearubens Sarg.) seedlings were exposed to 12 treatment regimes of acid fog deposition and heavy metal soil amendment over a 2-year period. Seedling health was assessed by measuring five health indices, including general vigor estimate, height, diameter, bud number, and biomass (leaf, stem, and twig, and total). Soil was amended with cadmium, copper, lead, manganese, nickel, and zinc added in amounts comparable to high-elevation forest soils in the northeastern United States. Seedlings were also treated with simulated fog, with ionic chemistry similar to high-elevation northeastern fog events, adjusted to pH 3 or 5. The seedlings were planted in metal-amended soil and subjected to fog treatments in greenhouse chambers from August 6, 1986, to October 29, 1987, in weekly regimes of 30-h exposures. Of all the seedling stress factors imposed, only the lead amendment at 2000 ppm concentration, which is approximately 10 times the current ambient forest floor high-elevation level, had a consistently adverse impact on the seedling health parameters measured. Vigor rating of experimental seedlings was adversely impacted by precipitaton acidity in the absence of lead and other heavy metal soil amendments. Height, diameter, and live bud count of the seedlings were quite insensitive to treatment conditions. Treatment interactions were also generally unimportant.
35
Pereira, Isabella C., Hugo C. R. M. Catão, and Franciele Caixeta. "Seed physiological quality and seedling growth of pea under water and salt stress." Revista Brasileira de Engenharia Agrícola e Ambiental 24, no. 2 (2020): 95–100. http://dx.doi.org/10.1590/1807-1929/agriambi.v24n2p95-100.
Full textAbstract:
ABSTRACT The aim of this study was to evaluate seed physiological quality and initial pea (Pisum sativum) seedling development at different water and salt potentials. Polyethylene glycol 6000, sodium chloride and potassium chloride solutions with different osmotic potentials (0; -0.2; -0.4; -0.6; -0.8; -1.0, and -1.2 MPa) were used, and the experiment had a 3 × 7 factorial arrangement. The physiological quality and initial seedling growth characteristics (first germination count, final germination count, strong normal seedlings, epicotyl and taproot lengths, epicotyl dry matter, and root dry matter) were evaluated in a completely randomized experimental design, with four repetitions. Decreases in the observed variables showed that the simulated stress conditions negatively affected physiological performance, germination and initial seedling growth. The water and salt stresses induced by the sodium chloride and potassium chloride solutions were greater than the stress induced by polyethylene glycol 6000.
36
Creus, Cecilia M., Rolando J. Sueldo, and Carlos A. Barassi. "Water relations in Azospirillum-inoculated wheat seedlings under osmotic stress." Canadian Journal of Botany 76, no. 2 (1998): 238–44. http://dx.doi.org/10.1139/b97-178.
Full textAbstract:
Azospirillum has been shown to improve coleoptile growth in seedlings growing in darkness under osmotic stress. However, the changes in water relations that may occur in this experimental system have not yet been studied. Two-centimetre long Triticum aestivum cv. Buck Pucará and Triticum durum cv. Balcarceño-INTA seedlings were inoculated with viable or autoclaved (control) Azospirillum brasilense Sp. 245 bacteria, at approximately 108 cells per seedling. Three days after inoculation, seedlings were exposed to osmotic stress by immersing their roots in 20% polyethylene glycol 6000 for up to 72 h. Germination and seedling growth were at 20°C in darkness. Shoots were excised after 72 h of stress, and water-status parameters were determined through pressure-volume analyses. While osmotic potential at full turgor remained constant, Azospirillum-stimulated growth in Buck Pucará seedlings was accompanied by significant decreases in osmotic potential and relative water content at zero turgor, in volumetric cell wall modulus of elasticity, and in absolute symplastic water volume and by a significant rise in apoplastic water fraction parameters. Except for a constant volumetric cell wall modulus of elasticity, similar results were obtained with Balcarceño-INTA seedlings. However, bacterial growth promotion was evident only in the less tolerant cv. Buck Pucará. Turgor at low water potential was higher in inoculated seedlings in both wheat cultivars under osmotic stress. These results are consistent with a better water status in Azospirillum-inoculated wheat seedlings under water stress, where both effects on cell wall elasticity and (or) apoplastic water are evident.Key words: Azospirillum, drought, seedlings, water status, wheat.
37
Anwar, Ali, Longqiang Bai, Li Miao, et al. "24-Epibrassinolide Ameliorates Endogenous Hormone Levels to Enhance Low-Temperature Stress Tolerance in Cucumber Seedlings." International Journal of Molecular Sciences 19, no. 9 (2018): 2497. http://dx.doi.org/10.3390/ijms19092497.
Full textAbstract:
Phytohormone biosynthesis and accumulation are essential for plant growth and development and stress responses. Here, we investigated the effects of 24-epibrassinolide (EBR) on physiological and biochemical mechanisms in cucumber leaves under low-temperature stress. The cucumber seedlings were exposed to treatments as follows: NT (normal temperature, 26 °C/18 °C day/night), and three low-temperature (12 °C/8 °C day/night) treatments: CK (low-temperature stress); EBR (low-temperature and 0.1 μM EBR); and BZR (low-temperature and 4 μM BZR, a specific EBR biosynthesis inhibitor). The results indicated that low-temperature stress proportionately decreased cucumber seedling growth and the strong seedling index, chlorophyll (Chl) content, photosynthetic capacity, and antioxidant enzyme activities, while increasing reactive oxygen species (ROS) and malondialdehyde (MDA) contents, hormone levels, and EBR biosynthesis gene expression level. However, EBR treatments significantly enhanced cucumber seedling growth and the strong seedling index, chlorophyll content, photosynthetic capacity, activities of antioxidant enzymes, the cell membrane stability, and endogenous hormones, and upregulated EBR biosynthesis gene expression level, while decreasing ROS and the MDA content. Based on these results, it can be concluded that exogenous EBR regulates endogenous hormones by activating at the transcript level EBR biosynthetic genes, which increases antioxidant enzyme capacity levels and reduces the overproduction of ROS and MDA, protecting chlorophyll and photosynthetic machinery, thus improving cucumber seedling growth.
38
Kumari, Archana, and Satish C. Bhatla. "Regulation of salt-stressed sunflower (Helianthus annuus) seedling's water status by the coordinated action of Na+/K+ accumulation, nitric oxide, and aquaporin expression." Functional Plant Biology 48, no. 6 (2021): 573. http://dx.doi.org/10.1071/fp20334.
Full textAbstract:
Among abiotic stresses, salt stress is a major threat to crop production all over the world. Present work demonstrates the profuse accumulation of Na+ in 2-day-old, dark-grown sunflower (Helianthus annuus L.) seedlings roots in response to salt stress (NaCl). The pattern of K+ accumulation in response to salt stress is similar to that of Na+ but on relatively lower scale. Application of nitric oxide (NO) donor (DETA) scales down Na+ accumulation in salt-stressed seedlings. The impact of NO donor on K+ accumulation is, however, different in control and salt-stressed seedling roots. In control seedlings, it enhances K+ accumulation, whereas, it gets reduced in salt-stressed seedlings. Specialised channels called ‘aquaporins’ (AQPs) play a major role maintaining the water status and transport across plant parts under salt-stress. Thus, accumulation of plasma-membrane intrinsic proteins (PIPs) and tonoplast-intrinsic proteins (TIPs), localised on plasma-membrane and vacuolar-membrane, respectively was undertaken in 2-day-old, dark-grown seedling roots. Salt stress increased the abundance of these isoforms, whereas, NO application resulted in decreased accumulation of PIP2 and TIP1. PIP1 and TIP2 isoforms remained undetectable. Present work thus, puts forward a correlation between AQP expression and ions (Na+ and K+) homeostasis in response to salt stress and NO.
39
Çavuşoğlu, Kürşat, and Hatice Güneş Ergin. "Effects of humic acid pretreatment on some physiological and anatomical parameters of barley (Hordeum vulgare L.) exposed to salt stress." Bangladesh Journal of Botany 44, no. 4 (2018): 591–98. http://dx.doi.org/10.3329/bjb.v44i4.38595.
Full textAbstract:
The effects of humic acid (HA) pretreatment on the seed germination, seedling growth and leaf anatomy of barley under both normal and saline conditions were studied. HA application partly reduced the final germination percentage, coleoptile percentage, radicle lenght, radicle number and fresh weight of barley germinated under normal conditions while it showed statistically the same effect as the control on the coleoptile length. In parallel with concentration rise, salt inhibited the seed germination and seedling growth of barley. The inhibitive effect of salt on the seed germination and seedling growth was alleviated in varying degrees by HA pretreatment. Moreover, salinity of the medium caused changes in the leaf anatomy of seedlings. HA affected in different degrees the various parameters of leaf anatomy of barley seedlings grown in both normal and saline conditions, and this difference was statistically important.
40
Fardus, Jannatul, Md Shahadat Hossain, and Masayuki Fujita. "Modulation of the Antioxidant Defense System by Exogenous l-Glutamic Acid Application Enhances Salt Tolerance in Lentil (Lens culinaris Medik.)." Biomolecules 11, no. 4 (2021): 587. http://dx.doi.org/10.3390/biom11040587.
Full textAbstract:
Salt stress greatly disturbs the growth, morpho-physiological, and biochemical performance of plants. However, different physiological processes and acclimation mechanisms can be induced under stress, while some of them can be modulated by the appropriate chemical stimulus. The objective of this study was to evaluate the impact of exogenous pretreatment with 10 mM l-glutamic acid (l-Glu) on the physiological and biochemical parameters of lentil (Lensculinaris Medik.) under 110 mM NaCl stress. Salt stress inhibited the growth and reduced the photosynthetic pigment (chlorophylls and carotenoids) level, water content, and survival of lentil seedlings during recovery from the stress. Salt stress also induced oxidative damage, as indicated by higher hydrogen peroxide and malonaldehyde contents and electrolyte leakage, by interrupting the antioxidant defense system and promoting the accumulation of toxic levels of Na+. However, l-Glu pretreatment mitigated the salt-induced damage in lentil seedlings by reducing the accumulation of Na+, maintaining ion homeostasis, and increasing the activities of antioxidant enzymes (catalase and ascorbate peroxidase). As a result, salt-induced oxidative damage was reduced, seedling growth and photosynthetic pigment contents were enhanced, and the survival rate of the lentil seedlings was improved in response to salt stress, indicating an ameliorative role for l-Glu in lentil seedling growth under salt stress.
41
Dranski, João Alexandre Lopes, Ubirajara Contro Malavasi, Marlene de Matos Malavasi, and Douglass Frederick Jacobs. "Effect of ethephon on hardening of Pachystroma longifolium seedlings." Revista Árvore 37, no. 3 (2013): 401–7. http://dx.doi.org/10.1590/s0100-67622013000300003.
Full textAbstract:
Immediately after planting, tree seedlings face adverse environmental and biotic stresses that must be overcome to ensure survival and to yield a desirable growth. Hardening practices in the nursery may help improve seedling stress resistance through reduction of aboveground plant tissues and increased root volume and biomass. We conducted an assay to quantify changes in the morphogenesis following application of ethephon on seedlings of Pachystroma longifolium (Ness) I. M. Johnst.during hardening. The results showed no effect of the ethephon treatments on the number of leaves but a reduction of up to 50% in seedling height increment, and an increase in stem diameter increment of up to 44% with the 600 mg L-1 ethephon treatment, which consequently altered seedling Dickson Quality Index. Our results indicate that ethephon may help to promote desired morphological changes that occur during seedling hardening in nurseries.
42
Harrison, Susan, and Marina LaForgia. "Seedling traits predict drought-induced mortality linked to diversity loss." Proceedings of the National Academy of Sciences 116, no. 12 (2019): 5576–81. http://dx.doi.org/10.1073/pnas.1818543116.
Full textAbstract:
Trait-based approaches are increasingly used to predict ecological consequences of climate change, yet seldom have solid links been established between plant traits and observed climate-driven community changes. Most analyses have focused on aboveground adult plant traits, but in warming and drying climates, root traits may be critical, and seedlings may be the vulnerable stage. Relationships of seedling and root traits to more commonly measured traits and ecological outcomes are poorly known. In an annual grassland where winter drought-induced seedling mortality is driving a long-term decline in native diversity, using a field experiment during the exceptionally dry winter of 2017–2018, we found that seedling mortality was higher and growth of seedlings and adults were lower in unwatered than watered sites. Mortality of unwatered seedlings was higher in species with shorter seedling roots, and also in species with the correlated traits of small seeds, high seedling specific leaf area (SLA), and tall seedlings. Adult traits varied along an axis from short-stature, high SLA and foliar N, and early flowering to the opposite values, and were only weakly correlated with seedling traits and seedling mortality. No evidence was found for adaptive plasticity, such as longer roots or lower SLA in unwatered plants. Among these species, constitutive variation in seedling root length explained most of the variation in survival of a highly vulnerable life stage under winter drought. Selective loss of species with high adult SLA, observed in this community and others under drought stress, may be the byproduct of other correlated traits.
43
Dufault, Robert J., and Regina R. Melton. "Cyclic Cold Stresses before Transplanting Influence Tomato Seedling Growth, but Not Fruit Earliness, Fresh-market Yield, or Quality." Journal of the American Society for Horticultural Science 115, no. 4 (1990): 559–63. http://dx.doi.org/10.21273/jashs.115.4.559.
Full textAbstract:
Tomato seedlings (Lycopersicon esculentum Mill. `Sunny') were exposed to cyclic cold stress at 2 ± 1C, then to 29 ± 6C in a greenhouse before being transplanted to the field. Cold-stressed seedlings were transplanted when the risk of ambient cold stress was negligible. In the first year of a 2-year study, transplants were exposed to 2C for 3, 6, or 12 hours for 1, 3, or 6 days before field planting. In the second year, transplants were exposed to 2C for 6, 12, or 18 hours for 4, 7, or 10 days before field planting. In the first year, cold stress generally stimulated increases in seedling height, leaf area, and shoot and root dry weights but decreased chlorophyll content. In the second year, all seedling growth characteristics except leaf area and plant height were diminished in response to longer cold-stress treatment. In both years, earliness, total productivity, and quality were unaffected by any stress treatment. Therefore, cold stress occurring before transplanting has a negligible effect on earliness, yield, or quality.
44
Fensham, R. J., R. J. Fairfax, and Y. M. Buckley. "An experimental study of fire and moisture stress on the survivorship of savanna eucalypt seedlings." Australian Journal of Botany 56, no. 8 (2008): 693. http://dx.doi.org/10.1071/bt08152.
Full textAbstract:
Eucalyptus melanophloia and E. populnea dominate large areas of savanna in eastern Australia. Under aboriginal management, fires probably occurred under a broad range of conditions, but under pastoral management, burning is avoided when soil moisture is low. This experiment subjected E. melanophloia and E. populnea seedlings to burning and moisture stress, to examine whether this change in burning regime could affect seedling survivorship. The findings suggest survivorship rates are 87–93% for unstressed seedlings with relatively large lignotubers (>12 mm2 plan area) and 56–66% for unstressed seedlings with small lignotubers. There was no substantial interactive effect between moisture stress and burning for E. melanophloia, but such an interaction was apparent for E. populnea, such that moisture stress multiplied the effect of burning. The timing of burning in relation to soil-moisture conditions may have an enduring effect on woodland structure where E. populnea is dominant. E. melanophloia seedlings are more resistant to burning, especially with moisture stress, and fire may not be limiting structural development in woodlands where this species dominates. However, a more detailed understanding of species demography is required, including the conditions required for germination, causes of seedling mortality and the time taken for seedlings to develop fire resistance in the field.
45
Liu, Xiaoming, Yao Meng, Shi Wei, and Wanrong Gu. "Exogenous Hemin Confers Cadmium Tolerance by Decreasing Cadmium Accumulation and Modulating Water Status and Matter Accumulation in Maize Seedlings." Agronomy 11, no. 4 (2021): 739. http://dx.doi.org/10.3390/agronomy11040739.
Full textAbstract:
Cadmium (Cd) contamination harms plant growth and human health. The application of hemin (ferroprotoporphyrin IX) can effectively relieve abiotic stresses in plants. This work investigates the effects of hemin on alleviating Cd toxicity and enhancing Cd tolerance in maize seedlings. In this study, maize seedlings were cultivated in nutrient solutions, with a combination of CdCl2 (464 μmol L−1) and hemin (100 μmol L−1). We measured plant growth status, water status, Cd concentration, and Cd distribution in maize seedlings. The results indicated that Cd stress increased Cd accumulation in plants and inhibited plant growth. However, hemin alleviated the growth inhibition and improved water balance, root morphology, and root vitality under Cd stress. Additionally, hemin increased 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), total phenolic content, and phenylalanine ammonia lyase (PAL) activity to enhance tolerance to Cd stress. Hemin reduced Cd concentration, the translocation factor (TF), and the bioconcentration factor (BCF) in maize seedlings under Cd stress. Furthermore, hemin increased Cd concentrations in the cell wall and the soluble fraction of seedling roots, which helped reduce Cd transport from root to shoot. In summary, exogenous hemin could be used for alleviating adverse impacts on maize seedling induced by Cd stress.
46
Leskovar, Daniel I., and Peter J. Stoffell. "SEEDLING ROOT AND SHOOT COMPONENTS IN RELATION TO STAND ESTABLISHMENT." HortScience 29, no. 5 (1994): 572f—572. http://dx.doi.org/10.21273/hortsci.29.5.572f.
Full textAbstract:
Initiation, development, and subsequent growth of seedling root and shoot components can have a direct influence on the quality, adaptation, and survival of seedlings, particularly under stress conditions. Taproot, basal, lateral, and adventitious root components (common indicot plants) each have their own development sequence, growth rate, and may have separate functions for subsequent seedling growth and development. Stresses originating in root components may be expressed in shoots affecting dry matter partitioning between roots and shoots. Partitioning and development of root morphological components and root/shoot growth adaptation to stress environments will be presented for various vegetable species. Implications of root developmental differences in relation to field planting methods will be discussed. Understanding seedling morphology, physiology and assimilate partitioning during early ontogeny would assist directing strategies to improve field establishment and ultimately crop production.
47
Sohrabikertabad, S., A. Ghanbari, H. R. Mohassel, Mohamad, M. N. Mahalati, and J. Gherekhloo. "Effect of desiccation and salinity stress on seed germination and initial plant growth of Cucumis melo." Planta Daninha 31, no. 4 (2013): 833–41. http://dx.doi.org/10.1590/s0100-83582013000400009.
Full textAbstract:
Smellmelon, an annual invasive weed of soybean production fields in the north of Iran, reproduces and spreads predominately through seed production. This makes seed bank survival and successful germination essential steps in the invasive process. To evaluate the potential of Smellmelon to invade water-stressed environments, laboratory studies were conducted to investigate the effect of desiccation and salinity at different temperatures on seed germination and seedling growth of Cucumis melo. Seeds were incubated at 25, 30, 35 and 40 ºC in the darkness in a solution (0, -0.2, -0.4, -0.6, -0.8, 1 and 1.2 MPa) of a salt (NaCl), and in a solution (0, -2, -4, -6, -8, -10, -12 bar) of PEG-6000 (Polyethylene glycol), in two separate experiments. The results showed that the highest percentage and rate of germination occurred at 35 ºC in salt concentrations of 0, -0.2, -0.4 MPa and PEG concentrations of 0, -2, -4 bar. Increasing the concentration of salt (NaCl) and PEG limited germination, seedling growth and water uptake but increased the sodium content in the seedlings. No significant difference was observed among 0, -0.2 and -0.4 MPa of NaCl and among 0, -2 and -4 bar of PEG concentration at 35 ºC. The negative effects of PEG were more than those of NaCl on germination percentage and germination rate. Increased stress levels lead to reduction of root and shoot length, and SVL of seedlings. Na+ content of seedling decreased with limited seedling growth of C. melo.
48
South, David, and Ryan Nadel. "Irrigation in pine nurseries." Reforesta, no. 10 (December 30, 2020): 40–83. http://dx.doi.org/10.21750/refor.10.05.88.
Full textAbstract:
This review provides information and opinions about irrigation practices in pine nurseries. Even when nurseries receive more than 15 mm of rainfall week-1, managers irrigate seedbeds to increase germination, increase seed efficiency, and increase root growth. In the southern United States, a 7-month old pine seedling in an outdoor nursery typically receives 2 to 6 kg of water supplied from either sprinklers (39 nurseries) or center-pivot irrigation (12 nurseries). Most nursery managers do not intentionally subject the crop to moisture stress, since most reforestation sites receive adequate rainfall, and many studies show that reducing root mass does not increase seedling performance. In fact, nursery profits can be reduced by more than $13,000 ha-1 when deficit irrigation reduces average seedling diameter by 1 mm. Although some researchers believe that failure to properly drought stress pine seedlings might increase outplanting mortality by up to 75%, research over the past 40 years does not support that myth. When pine seedlings average 5 mm (at the root-collar), water stress is not a reliable method of increasing tolerance to an October freeze event. In several greenhouse trials, researchers grew and tested seedlings that nursery managers would classify as culls (i.e., dry root mass < 0.5 g). Unfortunately, it is common for researchers to make irrigation recommendations without first developing a water-production function curve.
49
Jiang, Xu-Wen, Cheng-Ran Zhang, Wei-Hua Wang, Guang-Hai Xu, and Hai-Yan Zhang. "Seed Priming Improves Seed Germination and Seedling Growth of Isatis indigotica Fort. under Salt Stress." HortScience 55, no. 5 (2020): 647–50. http://dx.doi.org/10.21273/hortsci14854-20.
Full textAbstract:
The effects of CaCl2, GA3, and H2O2 priming on Isatis indigotica Fort. seed germination characteristics, seedling growth parameters, and antioxidant enzyme activities under salt stress were investigated. NaCl had an adverse effect on the germination and seedling performance of I. indigotica. However, these three priming agents alleviated salt stress by increasing the germination percentage, improving seed vigor, accelerating germination velocity, and establishing strong seedlings. The optimal concentrations were 15 g/L for CaCl2, 0.2 g/L for GA3, and 40 mm for H2O2. Seed priming treatments enhanced the activities of antioxidant enzymes in seedlings, such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), under a salt environment, which reduced the oxidative injury caused by salt. Seed priming is a promising technique that can enhance the ability of I. indigotica seed germination when salt is present.
50
Tome Yamamoto, Cláudia Jaqueline, Mariana Bassanezi Gasparim, Nelson Barbosa Machado-Neto, and Ceci Castilho Custodio. "Early Seedling Growth as a Tool to Assess the Tolerance of Urochloa brizantha Cultivars to Free Aluminium." Journal of Agricultural Science 10, no. 7 (2018): 67. http://dx.doi.org/10.5539/jas.v10n7p67.
Full textAbstract:
In this study we aimed to evaluate changes in germination, early seedling growth, and some biochemical parameters in Urochloa brizantha cultivars (Basilisk, Marandu, MG4, MG5, BRS Piatã, and Xaraés) subjected to five levels of free aluminium toxicity (0, 1, 2, 4, and 8 mmolc dm³ Al³+), and to verify the selection efficiency of aluminium tolerant cultivars. In the germination assay, lots were submitted to germination under simulated stress conditions in the laboratory, to quantify root protrusion, number of normal seedlings, shoot and root length, and dry mass. In the early seedling growth assay, evaluations were done on the seventh day after subjecting seedlings to aluminium stress conditions. Relative growth rate of length, and dry mass of shoots and roots, superoxide dismutase activity (SOD), and concentrations of proline, total antioxidants (TEAC), and malondialdehyde (MDA) were evaluated. During the seedling study period, up to 14 days after sowing, the most tolerant cultivar maintained root growth in aluminium stress conditions, while the most susceptible cultivar reduced root growth, and developed proportionally more shoots, as shoot growth depends on seed reserves. The germination assay indicated interference of the initial seed quality with increasing Al3+ concentrations. The results indicate that the early seedling growth assay, which excluded germination effects, and used the measurement of root attributes, is appropriate for the discrimination of Al3+ tolerant genotypes. The Marandu cultivar was the most similar to the Al3+ tolerance standard Basilisk cultivar.