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Journal articles on the topic 'Seedling Elongation'
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1
Tripathi, R. S. "Genetics of Seedling Elongation in Rice." International Rice Research Newsletter 13, no. 2 (1988): 4. https://doi.org/10.5281/zenodo.7128504.
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This article 'Genetics of Seedling Elongation in Rice' appeared in the International Rice Research Newsletter series, created by the International Rice Research Institute (IRRI). The primary objective of this publication was to expedite communication among scientists concerned with the development of improved technology for rice and for rice based cropping systems. This publication will report what scientists are doing to increase the production of rice in as much as this crop feeds the most densely populated and land scarce nations in the world.
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Liptay, Albert, John L. Barron, Tom Jewett, and Ian van Wesenbeeck. "Oscillations in Corn Seedling Growth as Measured by Optical Flow." Journal of the American Society for Horticultural Science 120, no. 3 (1995): 379–85. http://dx.doi.org/10.21273/jashs.120.3.379.
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Growth of corn seedlings during the coleoptile stage was measured using optical flow. The measurement system was comprised of a digital camera, computer, and related software and measured growth in a continuous, noncontact manner. The use of optical flow to measure shoot elongation, i.e., image motion of the elongating seedling, was most easily computed when there were large spatiotemporal variations of the motion of the corn seedling against the background. The sensitivity of the measurement technique was in the micron per second range. Seedling growth did not occur in a smooth even manner, rather, growth was a series of varying bursts or waves of expansion that appeared to be affected by the physical growth or development of the leaves. Spectral analysis techniques were applied to extract the underlying signal from the observed time series of seedling growth rate and angle.
3
Adams, A. S., and L. K. Rieske. "Herbivory and Fire Influence White Oak (Quercus alba L.) Seedling Vigor." Forest Science 47, no. 3 (2001): 331–37. http://dx.doi.org/10.1093/forestscience/47.3.331.
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Abstract We manipulated arthropod and mammalian herbivory levels on white oak seedlings using a combination of insecticide applications and fencing and employed a split-split-plot design to assess the impact of single- and multiple-year burns on seedling growth over a 2 yr period. Herbivory levels increased over time on all sites, but there was no significant difference in herbivore pressure on seedlings in single-year burned, multiple-year burned, and nonburned plots. Insecticide-treated seedlings suffered less herbivore pressure than did noninsecticide treated seedlings, and mammalian herbivory was significantly reduced by the presence of a fence. Seedling height growth, shoot elongation, diameter growth, and specific leaf mass were greatest on once-burned sites, intermediate on twice-burned sites, and least on nonburned sites. Bud expansion was the only seedling performance parameter unaffected by burn treatment. Arthropod feeding was the greater component of overall herbivory, but this herbivory did not impede seedling growth. Seedling height growth and shoot elongation were more closely linked to mammalian herbivory. These results suggest that the observed herbivory may play a negligible role, and prescribed fire may be a beneficial component of a management program designed to enhance oak regeneration. FOR. SCI. 47(3):331–337.
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Li, Shuhao, Jun Tian, Shengxiang Ran, Yuqi Zhou, Hongdou Gao, and Fenglin Zhong. "Hormone Signals Involved in the Regulation of Cucumber Seedling Lateral Branch Elongation by Far-Red Light." Agronomy 14, no. 2 (2024): 366. http://dx.doi.org/10.3390/agronomy14020366.
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Cucumber (Cucumis sativus L.) lateral branch elongation is influenced by a variety of environmental signals, including light [e.g., far-red (FR) light] and hormones. In this experiment, the effect of FR light on the lateral branch elongation of cucumber (‘Zhongnong No. 26’) seedlings was investigated. The results showed that FR light significantly inhibited the lateral branch elongation of cucumber seedlings. In addition, FR light significantly increased the auxin (indole-3-acetic acid, IAA) content, decreased the cytokinin (CTK; Zeatin) content, and suppressed the expression of most CTK synthetic-related genes, such as IPTs, in cucumber seedlings. The lateral branch elongation of cucumber seedlings was assessed in response to decapitation and exogenous 6-BA treatment to further investigate the relationship between IAA and CTK on the lateral branch elongation of cucumber seedlings under FR light. Both decapitation and exogenous 6-BA treatment eliminated the inhibitory effect of FR light on the lateral branch elongation of cucumber seedlings. In conclusion, these results indicated that IAA and CTK were involved in the regulatory effects of FR light on cucumber seedling lateral branch elongation.
5
Edelman, Nichole F., Bethany A. Kaufman, and Michelle L. Jones. "Comparative Evaluation of Seedling Hypocotyl Elongation and Mature Plant Assays for Determining Ethylene Sensitivity in Bedding Plants." HortScience 49, no. 4 (2014): 472–80. http://dx.doi.org/10.21273/hortsci.49.4.472.
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Ethylene gas can cause extensive damage to bedding plants during production, shipping, and retailing. Seedlings exposed to ethylene exhibit the triple response, which includes an exaggerated apical hook, thickened hypocotyl, and reduced hypocotyl elongation. Our objective was to determine if the hypocotyl elongation component of the seedling triple response could be used to predict the sensitivity of mature plants at the marketable stage. Eighteen common bedding plants were evaluated. For the seedling hypocotyl elongation screen, seeds were germinated and grown in the dark on filter paper saturated with various concentrations of 1-aminocyclopropane-1-carboxylic acid (ACC; the immediate precursor to ethylene). The relative hypocotyl length at each ACC concentration was compared with untreated control (0 μM) seedlings. Mature plants, with at least four open flowers, were treated with ethylene (0, 0.01, 0.1, 1, or 10 μL·L−1) in the dark for 24 hours. Phenotypic responses to ethylene, including flower abscission, flower senescence, leaf abscission, leaf chlorosis, and epinasty, were rated on a scale of 0 to 5. Five species exhibited very little reduction in hypocotyl elongation when grown on ACC (low sensitivity). The remaining species were classified as medium or high ethylene sensitivity at the seedling stage. The most common symptoms of ethylene damage observed in mature plants were leaf epinasty, flower abscission, and flower senescence. The severity of these responses was used to identify plants with high, medium, or low sensitivity to ethylene. For six of the bedding plant species that were equally responsive at both developmental stages, the seedling hypocotyl elongation screen would provide a reliable means of predicting the ethylene sensitivity of mature plants.
6
Li, Bailian, S. E. McKeand, and H. L. Allen. "Seedling shoot growth of loblolly pine families under two nitrogen levels as related to 12-year height." Canadian Journal of Forest Research 21, no. 6 (1991): 842–47. http://dx.doi.org/10.1139/x91-118.
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Seedling shoot elongation and biomass were examined for 23 open-pollinated loblolly pine (Pinustaeda L.) families grown in a greenhouse under two nitrogen regimes. Significant genetic variation was detected among families for the number of growth cycles, total seedling height, cyclic-growth elongation, the number of stem units, and biomass of stem free growth, cyclic growth, total stem, needles, and total shoot. Heritability estimates were generally high for shoot characteristics except for mean stem-unit length. Shoot biomass measures were weakly or negatively correlated with 12-year-height performance. Elongation of cyclic growth, number of growth cycles, and number of stem units showed stronger correlations with field performance than did seedling height. Juvenile–mature correlations were higher for the low nitrogen treatment, suggesting that 12-year height of loblolly pine families can be more accurately predicted when the seedlings are grown under greenhouse conditions that mimic field nitrogen levels.
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Jeong, Hyeon Woo, Hye Ri Lee, Hyeon Min Kim, Hye Min Kim, Hee Sung Hwang, and Seung Jae Hwang. "Using Light Quality for Growth Control of Cucumber Seedlings in Closed-Type Plant Production System." Plants 9, no. 5 (2020): 639. http://dx.doi.org/10.3390/plants9050639.
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During seedling production, growth control of seedlings is an important problem because the overgrowth of seedlings causes a decrease of seedling quality and has disadvantages after transplanting. In this study, we aim to evaluate the possibility of replacing chemical plant growth regulators using light quality in a closed-type plant production system (CPPS) for cucumber seedling production. We used various light treatments, such as monochromatic or combined red (R) and blue (B), and combined R and B with UV-A or Far-red (Fr) light, to compare with a chemical plant growth regulator conventionally using in nursery farms. The combined R and B treatment decreased stem elongation and increased dry matter and compactness. UV-A treatment increased compactness but did not significantly affect the stem elongation or dry matter. Fr increased stem elongation and stem diameter and decreased compactness and dry matter. In leaf growth, combined R and B treatments and UV-A treatments increased leaf area, specific leaf weight, and SPAD value, and decreased leaf shape index. Fr treatments increased leaf area and leaf shape index and decreased specific leaf weight (SLW) and SPAD values. Cucumber seedlings have many different morphological changes, and R5B5 light quality was more effective in growth control due to higher compactness than chemical plant growth regulators. Also, R5B5 light quality has increased seedling quality, such as dry matter and SLW compared with fluorescent lamps. Thus, the use of light quality is a possible alternative to a chemical plant growth regulator.
8
Madela, Kazimierz, and Jan Kopcewicz. "Photoreceptive sites in the photocontrol of oat seedling growth." Acta Societatis Botanicorum Poloniae 58, no. 2 (2014): 229–36. http://dx.doi.org/10.5586/asbp.1989.018.
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The influence of red light on the growth of coleoptiles and mesocotyles of etiolated and pre-irradiated oat seedlings was investigated. Red light (15 min.) applied on whole seedlings stimulated the elongation of coleoptiles and inhibited the growth of mesocotyles both in etiolated and in pre-irradiated plants. Irradiation with red light (2 min) of various 2-mm-long regions of etiolated and pre-irradiated oat seedlings was carried out in order to locate their light reception regions. On the basis of growth reactions after such treatment it was found that in completely etiolated seedlings the light reception sites involved in the stimulation of coleoptile elongation and inhibition of mesocotyle growth lie directly above and below the seedling node, whereas in pre-irradiated seedlings, in the top of the seedling. These results point to the existence of different growth photoregulation systems in etiolated and pre-irradiated oat seedlings. The role of phytochrome in these phenomena is discussed.
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SAKPERE, Ayobola A. Moninuola, Matthew OZIEGBE, and Idowu Arinola BILESANMI. "Allelopathic Effects of Ludwigia decurrens and L. adscendens subsp. diffusa on Germination, Seedling Growth and Yield of Corchorus olitorious L." Notulae Scientia Biologicae 2, no. 2 (2010): 75–80. http://dx.doi.org/10.15835/nsb224629.
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This study examined the allelopathic effect of Ludwigia decurrens and L. adscendens exudates on germination, seedling growth (hypocotyl and radicle elongation), seedling mortality, vegetative growth and reproductive yield of Corchorus olitorious. Ludwigia decurrens, L. adscedens exudates and tap water (control) were applied to seeds of Corchorus olitorious over a period of 15 days and to 3 weeks old seedling for a period of 4 weeks. Ludwigia exudates had no inhibitory effect on the germination percentage of C. olitorious, but the exudates from the two Ludwigia spp. induced mortality rate of the 15 day old seedlings (control: 5.00%, L. decurrens: 17.50%, L. adscendens: 26.88%) and a significant decrease in seedling elongation (hypocotyl and radicle length) of C. olitorious. For the vegetative growth experiment, results showed that the stem length, stem fresh weight and leaf area of C. olitorious were significantly inhibited during week 6 (P
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Shi, Sujuan, Lulu An, Jingjing Mao, et al. "The CBL-Interacting Protein Kinase NtCIPK23 Positively Regulates Seed Germination and Early Seedling Development in Tobacco (Nicotiana tabacum L.)." Plants 10, no. 2 (2021): 323. http://dx.doi.org/10.3390/plants10020323.
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CBL-interacting protein kinase (CIPK) family is a unique group of serine/threonine protein kinase family identified in plants. Among this family, AtCIPK23 and its homologs in some plants are taken as a notable group for their importance in ions transport and stress responses. However, there are limited reports on their roles in seedling growth and development, especially in Solanaceae plants. In this study, NtCIPK23, a homolog of AtCIPK23 was cloned from Nicotiana tabacum. Expression analysis showed that NtCIPK23 is mainly expressed in the radicle, hypocotyl, and cotyledons of young tobacco seedlings. The transcriptional level of NtCIPK23 changes rapidly and spatiotemporally during seed germination and early seedling growth. To study the biological function of NtCIPK23 at these stages, the overexpressing and CRISPR/Cas9-mediated knock-out (ntcipk23) tobacco lines were generated. Phenotype analysis indicated that knock-out of NtCIPK23 significantly delays seed germination and the appearance of green cotyledon of young tobacco seedling. Overexpression of NtCIPK23 promotes cotyledon expansion and hypocotyl elongation of young tobacco seedlings. The expression of NtCIPK23 in hypocotyl is strongly upregulated by darkness and inhibited under light, suggesting that a regulatory mechanism of light might underlie. Consistently, a more obvious difference in hypocotyl length among different tobacco materials was observed in the dark, compared to that under the light, indicating that the upregulation of NtCIPK23 contributes greatly to the hypocotyl elongation. Taken together, NtCIPK23 not only enhances tobacco seed germination, but also accelerate early seedling growth by promoting cotyledon greening rate, cotyledon expansion and hypocotyl elongation of young tobacco seedlings.
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Brigard, Juan P., Richard L. Harkess, and Brian S. Baldwin. "Tomato Early Seedling Height Control Using a Paclobutrazol Seed Soak." HortScience 41, no. 3 (2006): 768–72. http://dx.doi.org/10.21273/hortsci.41.3.768.
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Tomato seedling hypocotyls elongate rapidly after germination resulting in weak seedlings. The effects of 0, 250, 500, 750, or 1000 mg paclobutrazol (PB)/L seed soak and soaking times from 1 to 12 hours on tomato (Solanum lycopersicum L.) seed germination, seedling growth, and plant growth were tested. Adequate height control was obtained with 250 mg PB/L while soaking time did not affect seedling growth. In a second experiment, PB was tested at 0, 50, 100, 150, 200, or 250 mg PB/L soaking the seed for 1 hour. A concentration of PB at 100 mg·L–1 provided optimum control of hypocotyl elongation with minimal residual effect on subsequent plant growth. In a third experiment, seed soaked at the different PB concentrations were germinated and grown under light intensities of 0.09, 50, 70, or 120 μmol·m–2·s–1. Seedlings grown under 0.09 μmol·m–2·s–1 were not affected by PB treatment and did not develop an epicotyl. PB seed soak treatment gave greater growth suppression under 50 μmol·m-2·s-1 than under the two higher light levels. Soaking tomato seeds in 100 mg PB/L for 1 hour prevented early hypocotyl stretch of tomato seedlings with no long term effects on plant growth. This treatment effectively prevented excessive hypocotyl elongation when seeds were germinated under low PAR while not over controlling elongation under high PAR conditions.
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Wang, Li, Zhuo Huang, Handong Gao, and Chao Ni. "A method for continuously monitoring the quality of Masson pine seedlings." PLOS ONE 16, no. 3 (2021): e0234592. http://dx.doi.org/10.1371/journal.pone.0234592.
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Root growth potential (RGP) is a popular physiological indicator used to evaluate seedling vigor. However, the time scale used in the RGP test is the order of days, which leads to poor performance of the RGP method. We propose an optical interference method, called statistical interferometry, to measure minute root elongation at a sub-nanometer scale, which can decrease the time used in measuring RGP. The time scale of this method is also 104 times less than that of the RGP method. Because we can measure the length of root elongation continuously, we can compute the root elongation rate (RER), which is the variety of the length of root elongation per second. Continuous monitoring can help determine the quality of Masson pine seedling as soon as possible. To show the effectiveness of our proposed method, we designed an experiment, in which we applied different water stresses to our collected Masson pine seedlings and acquired two groups of pines, representing two different qualities: one stressed by water and one not. After measuring the RER of the groups in our experiments, we found that RER is interrelated with the quality of seedlings.
13
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.
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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.
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Meeks, Martin, H. Brent Pemberton, Lurline Marsh, and Garry V. McDonald. "The Effect of UV-B Lamp Light on the Growth of Three Bedding Plant Species." HortScience 32, no. 4 (1997): 589A—589. http://dx.doi.org/10.21273/hortsci.32.4.589a.
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The effect of UV-B fluorescent lamp light on seedling elongation was investigated using three species: marigold (Tagetes sp.), cucumber (Cucumis sativa), and tomato (Lycopersicon esculentum). Seedlings were exposed to light supplied from two unshielded and unfiltered 40-watt UV-B fluorescent lamps. In two experiments, seedlings were placed a distance of 45 cm below the light for varying lengths of time, while seedlings were placed 60 cm below the light in a third experiment. For marigold, seedlings were shorter when germinated under the UV-B lamp than when germinated under natural light in a glasshouse. Two hours of exposure just after glasshouse germination (cotyledons unfolded) was effective in reducing height of cucumber seedlings, whereas 6 hours was required to significantly reduce the height of tomato seedlings. Treatments were still effective when the last measurements were taken 12 to 14 days after germination. Exposure of seedlings to UV-B lamp light provides a possible alternative means of preventing excessive seedling elongation instead of relying on chemical plant growth regulators.
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Pflugfelder, Daniel, Johannes Kochs, Robert Koller, et al. "The root system architecture of wheat establishing in soil is associated with varying elongation rates of seminal roots: quantification using 4D magnetic resonance imaging." Journal of Experimental Botany 73, no. 7 (2021): 2050–60. http://dx.doi.org/10.1093/jxb/erab551.
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Abstract Seedling establishment is the first stage of crop productivity, and root phenotypes at seed emergence are critical to a successful start of shoot growth as well as for water and nutrient uptake. In this study, we investigate seedling establishment in winter wheat utilizing a newly developed workflow based on magnetic resonance imaging (MRI). Using the eight parents of the MAGIC (multi-parent advanced generation inter-cross) population we analysed the 4D root architecture of 288 individual seedlings grown in natural soils with plant neighbors over 3 d of development. Time of root and shoot emergence, total length, angle, and depth of the axile roots varied significantly among these genotypes. The temporal data resolved rates of elongation of primary roots and first and second seminal root pairs. Genotypes with slowly elongating primary roots had rapidly elongating first and second seminal root pairs and vice versa, resulting in variation in root system architecture mediated not only by root angle but also by initiation and relative elongation of axile roots. We demonstrated that our novel MRI workflow with a unique planting design and automated measurements allowed medium throughput phenotyping of wheat roots in 4D and could give new insights into regulation of root system architecture.
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CORDAZZO, C. V. "Effect of seed mass on germination and growth in three dominant species in southern Brazilian coastal dunes." Brazilian Journal of Biology 62, no. 3 (2002): 427–35. http://dx.doi.org/10.1590/s1519-69842002000300005.
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The effect of seed mass on germination and growth was tested in fresh-seeds of Blutaparon portulacoides, Panicum racemosum, and Spartina ciliata, selected at random in southern Brazilian populations. The seed mass varied within a population of the three species. Both B. portulacoides and P. racemosum showed normal frequency distribution of seed mass, while S. ciliata did not. Significant differences were observed in seed germination between large and small seeds of all species. In all species the capacity of seedling elongation was greater in seedlings of large seeds than those of small ones. Relative growth rate of seedlings of P. racemosum and S. ciliata decreased with time in all seed mass size-classes. On the other hand, the relative growth rate of B. portulacoides seedlings increased during the first 40 days. Seed mass is an important biological factor, affecting seed germination, seedling elongation, and growth of these species, and favoring large seeds, specially in areas of active sand accretion like coastal dunes.
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Bigras, Francine J., and Carole Hébert. "Freezing temperatures and exposure times during bud break and shoot elongation influence survival and growth of containerized black spruce (Piceamariana) seedlings." Canadian Journal of Forest Research 26, no. 8 (1996): 1481–89. http://dx.doi.org/10.1139/x26-165.
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Spring frosts frequently cause significant damage to conifer seedlings during bud flushing and shoot elongation in forestry nurseries. To insure adequate protection, levels of frost sensitivity must be known during these stages of development. Eight- or 9-month-old containerized black spruce seedlings (Piceamariana (Mill.) BSP) were submitted to freezing temperatures of 0° to −10 °C for 1–6 h at the following stages: (1) nonswollen terminal buds, (2) swollen terminal buds, (3) terminal bud scales bursting, needle tips emerging, and (4) shoots elongating, 1−5 cm. After freezing, seedlings were grown for 130 days in a greenhouse. Seedling survival was estimated; dead seedlings discarded; and damage to buds, needles, and roots as well as diameter and shoot increment were measured on the remaining seedlings. Frost sensitivity increased as buds flushed and new shoots elongated. Decreased seedling and bud survival was noted with increasing time of freezing exposure and decreasing temperature in stages 2, 3, and 4. Damage to needles and roots increases, while diameter decreases, with decreasing temperatures at all stages; however, shoot increment was influenced by decreasing temperatures only at stages 2 and 3.
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Gardarin, Antoine, Françoise Coste, Marie-Hélène Wagner, and Carolyne Dürr. "How do seed and seedling traits influence germination and emergence parameters in crop species? A comparative analysis." Seed Science Research 26, no. 4 (2016): 317–31. http://dx.doi.org/10.1017/s0960258516000210.
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AbstractEarly plant establishment through seed germination and seedling emergence is a crucial process that determines seedling number, emergence time distribution and the early growth of seedlings, all of which are affected by soil climate and soil structure. In the current context of climate change, in which increasing the diversity of cultivated species is considered desirable, and new tillage practices are considerably modifying top-soil surface characteristics, we need to improve our ability to model the effects of the environment on plant establishment. Using a trait-based and model-based framework, we aimed to identify general relationships between seed and seedling traits (e.g. seed mass and lipid content, seedling diameter, base temperature) and germination and emergence model parameters (e.g. time to mid-germination, shoot elongation rate) measured for 18 genotypes belonging to 14 species. Relationships were also investigated among model parameters or traits. Germination rates were faster for species with a high base temperature and for species with seed reserves located principally in the embryo (rather than the endosperm or perisperm). During heterotrophic growth, maximal shoot length and elongation rate increased with seed dry mass. The sensitivity of seedlings to soil obstacles was negatively related to shoot diameter. Thus apart from the known effects of seed mass on seedling establishment, we found that seed reserve location, seedling shoot diameter and shape affected germination rate and emergence success. Such generic rules linking plant traits to germination and emergence parameters enhance our understanding of the determinants of environmental effects on plant establishment success.
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Clark, David G., Christopher Dervinis, James E. Barrett, and Terril A. Nell. "Using a Seedling Hypocotyl Elongation Assay as a Genetic Screen for Ethylene Sensitivity of Seedling Geranium Cultivars." HortTechnology 11, no. 2 (2001): 297–302. http://dx.doi.org/10.21273/horttech.11.2.297.
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Experiments were conducted to determine if the seedling hypocotyl elongation and petal abscission assays could be used to identify differences in ethylene sensitivity among seedling geranium (Pelargonium ×hortorum) cultivars. When seedlings of six geranium cultivars were germinated and grown in the dark in the presence of the ethylene biosynthetic precursor 1-aminocyclopropane-1-carboxylic acid (ACC) at various concentrations, they exhibited the triple response (measured as reduced hypocotyl length). While seedlings from all six cultivars were sensitive to ACC, `Scarlet Elite' seedlings were most sensitive, and `Multibloom Lavender', `Elite White' and `Ringo 2000 Salmon' seedlings were the least sensitive when germinated and grown on 20 mm [2022 mg·L-1 (ppm)] ACC. Florets representing three developmental stages of each of the six cultivars were exposed to 1 μL·L-1 of exogenous ethylene for 0, 30, or 60 min to determine if differences in cultivar sensitivity could be determined for petal abscission. Of the six cultivars tested, `Ringo 2000 Salmon', `Multibloom Lavender' and `Elite White' were the least ethylene sensitive. Florets were also self-pollinated to test for cultivar differences in ethylene synthesis and subsequent petal abscission. Ethylene production and petal abscission were both promoted in self-pollinated florets compared to nonpollinated florets. `Ringo 2000 Salmon', `Multibloom Lavender' and `Elite White' florets produced similar amounts of ethylene as all other cultivars, but abscised fewer petals after pollination. Our results indicate that the seedling hypocotyls elongation assay may be used to identify geranium cultivars with reduced sensitivity to ethylene. The data also suggest that genetic variability exists among geraniums for both ethylene sensitivity and biosynthesis.
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Dwivedi, J. L., D. Senadhira, and D. Hillerislambers. "Plant Elongation At Three Seedling Ages in Some Rice Varieties." International Rice Research Notes 18, no. 1 (1993): 30. https://doi.org/10.5281/zenodo.6822718.
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This article 'Plant Elongation At Three Seedling Ages in Some Rice Varieties' appeared in the International Rice Research Notes series, created by the International Rice Research Institute (IRRI) to expedite communication among scientists concerned with the development of improved technology for rice and rice-based systems. The series is a mechanism to help scientists keep each other informed of current rice research findings. The concise scientific notes are meant to encourage rice scientists to communicate with one another to obtain details on the research reported.
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Waddington, John, and Marvin C. Snoop. "Using small tubes to measure root elongation of newly germinated alfalfa seedlings in relation to moisture." Canadian Journal of Plant Science 74, no. 2 (1994): 215–19. http://dx.doi.org/10.4141/cjps94-045.
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A method of growing newly germinated seedlings in small tubes was developed to enable the study of early root elongation. Three newly germinated alfalfa (Medicago sativa L.) seeds were placed in tubes of various diameters and volumes filled with sand at several moisture tensions, and the tubes were sealed to prevent moisture loss. For the first 4 d, roots elongated at approximately 8 mm d−1 in polyvinyl chloride plastic tubes holding 60 mL of sand with a moisture tension of 100 kPa or less. After the initial 4 d, root elongation continued at a slower rate, and branch roots developed before termination of the experiments at 12 d after germination. At a moisture tension of 300 kPa, root elongation was markedly less than at 100 kPa, and was zero at moisture tensions of 500 kPa or greater. In round-bottom glass tubes, root elongation rate was significantly slower in a sand volume of 23 mL than in 65 mL, and there was evidence of slower seedling development as the diameter of the tubes was reduced from 20 to 15 mm. Wax plus masking tape or nylon tape were equally effective in sealing the sides of tubes formed from the two halves of a plastic pipe previously cut lengthwise. A plastic cap plus wax was significantly better than plastic film for sealing the bottom ends of plastic tubes. Neither aeration nor replacement of water with a dilute nutrient solution had an effect on root elongation of young seedlings. Key words: Alfalfa, seedling, root elongation, moisture stress, Medicago sativa
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Mukherji, S., and A. K. Biswas. "Penicillin action stimulating growth and metabolism in seedlings of rice (Oryza sativa)." Canadian Journal of Botany 63, no. 6 (1985): 1150–56. http://dx.doi.org/10.1139/b85-158.
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Penicillin promoted elongation of rice (Oryza sativa L.) seedlings; the relative promotion of shoot elongation was stronger than that of root elongation. Nucleic acids and protein were maintained at much higher levels in seedlings treated with penicillin, the increment of these metabolites being more pronounced in the embryo than in the endosperm. α-Amylase, RNase, and ATPase of endosperm and indoleacetic acid (IAA) oxidase activities of the entire seedlings were enhanced in penicillin treatments. Penicillin caused small increments in respiration rates of seedlings. IAA-induced growth inhibition of intact seedlings could be reversed completely to a growth promotion by joint application of penicillin with IAA. The length of the second leaf sheath of a dwarf rice cultivar was increased by penicillin which further enhanced the gibberellin-induced response. The levels of gibberellinlike substances were increased by penicillin treatments, whereas the IAA level remained unchanged. In penicillin-treated seedlings, more IAA was transported from endosperm to embryo. The stimulating effect of penicillin on rice seedling elongation was partially reversed by abscisic acid and the interaction appeared to be of a noncompetitive nature.
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Redmann, R. E., and M. Q. Qi. "Impacts of seeding depth on emergence and seedling structure in eight perennial grasses." Canadian Journal of Botany 70, no. 1 (1992): 133–39. http://dx.doi.org/10.1139/b92-018.
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The effects of seeding depth (1.5, 3, or 6 cm) on seedling emergence, morphology, and anatomy were examined in cool-season (Agropyron dasystachyum, Agropyron desertorwn, Agropyron smithii, Elymus angustus, and Elymus junceus) and warm-season (Andropogon scoparius, Bouteloua curtipendula, and Bouteloua gracilis) perennial grasses. Caryopsis weights ranged from 0.5 mg in Bouteloua spp. to 4.7 mg in E. angustus. Prominent elongation of the subcoleoptile internode at greater seeding depths and short coleoptiles were observed in And. scoparius, B. curtipendula, and B. gracilis (type A seedlings). The remaining species had relatively long coleoptiles and no subcoleoptile internode elongation (type B seedlings). Up to 40% of the seedlings in the Agropyron species had intracoleoptile internode elongation when seeded at 3- and 6-cm depths. Relative emergence from 6 cm compared with 1.5 cm was best in Agr. dasystachyum and Agr. smithii and poorest in the type A species and in E. junceus. Diameters of xylem vessels in the subcoleoptile and intracoleoptile internodes remained relatively constant, but numbers of vesels decreased with depth of seeding, especially in the type A species. Decreases in hydraulic conductance with depth of seeding were greater in type A than in type B seedlings, mainly because of longer subcoleoptile internodes and smaller effective vessel radii in the former. Key words: grass seedling emergence, hydraulic conductance, morphology, seeding depth, seed weight, xylem dimensions.
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Roman, Erivelton S., A. Gordon Thomas, Stephen D. Murphy, and Clarence J. Swanton. "Modeling germination and seedling elongation of common lambsquarters (Chenopodium album)." Weed Science 47, no. 2 (1999): 149–55. http://dx.doi.org/10.1017/s0043174500091554.
Full textAbstract:
The ability to predict time of weed seedling emergence relative to the crop is an important component of a mechanistic model describing weed and crop competition. In this paper, we hypothesized that the process of germination could be described by the interaction of temperature and water potential and that the rate of seedling shoot and radicle elongation vary as a function of temperature. To test these hypotheses, incubator studies were conducted using seeds and seedlings of common lambsquarters. Probit analysis was used to account for variation in cardinal temperatures and base water potentials and to develop parameters for a new mathematical model that describes seed germination and shoot and radicle elongation in terms of hydrothermal time and temperature, respectively. This hydrothermal time model describes the phenology of seed germination using a single curve, generated from the relationship of temperature and water potential.
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Montgomery, Jill A., Ray A. Bressan, and Cary A. Mitchell. "Optimizing Environmental Conditions for Mass Application of Mechano-dwarfing Stimuli to Arabidopsis." Journal of the American Society for Horticultural Science 129, no. 3 (2004): 339–43. http://dx.doi.org/10.21273/jashs.129.3.0339.
Full textAbstract:
Obtaining uniform mechano-dwarfing of Arabidopsis thaliana (L.) Heynh. seedlings within dense plantings is problematic. Alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls in both greenhouse and controlled growth environments. Arabidopsis grown under low photosynthetic photon flux (PPF) artificial light grew upright with limited leaf expansion, which enhanced mechano-responsiveness compared to that of rosette-growing plants under filtered sunlight or high PPF artificial light. Hypocotyls of seedlings grown at PPFs >60 μmol·m-2·s-1 elongated less and had 6% less sensitivity to mechanical stress than seedlings grown at PPFs <60 μmol·m-2·s-1. Fluorescent lamps alone (F) or fluorescent plus incandescent (F+I) lamps were compared for seedling responses to mechanical stress. Under F lighting, hypocotyl elongation was reduced 25% to 40% by twice-daily brush or plate treatments, and brushed seedlings exhibited more growth reduction than did plate treatments. Seedlings grown under F+I lamps exhibited similar stress-induced growth reduction compared to seedlings grown under F only, but stressed F+I seedlings lodged to a greater extent due to excessive hypocotyl elongation. Temperature-response studies using standardized F-only lighting indicated increased hypocotyl elongation but decreased leaf expansion, and decreased mechano-responsivity to brushing over the temperature range from 20 to 28 °C. Daylength studies indicated similar degrees of mechano-inhibition of hypocotyl elongation over the daylength range of 12, 16, 20, and 24 hours, whereas fresh weight of stressed seedling shoots declined compared to controls. A combination of environmental growth parameters that give repeatable, visual mechanical dwarfing of Arabidopsis include low-PPF fluorescent lighting from 55 to 60 μmol·m-2·s-1, ambient temperatures from 22 to 25 °C, and twice-daily brush treatments.
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Montgomery, Jill A., Ray A. Bressan, and Cary A. Mitchell. "Optimizing Environmental Conditions for Mass Application of Mechano-dwarfing Stimuli to Arabidopsis." Journal of the American Society for Horticultural Science 129, no. 3 (2004): 339–43. https://doi.org/10.21273/jashs.129.3.339.
Full textAbstract:
Obtaining uniform mechano-dwarfing of Arabidopsis thaliana (L.) Heynh. seedlings within dense plantings is problematic. Alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls in both greenhouse and controlled growth environments. Arabidopsis grown under low photosynthetic photon flux (PPF) artificial light grew upright with limited leaf expansion, which enhanced mechano-responsiveness compared to that of rosette-growing plants under filtered sunlight or high PPF artificial light. Hypocotyls of seedlings grown at PPFs >60 μmol·m-2·s-1 elongated less and had 6% less sensitivity to mechanical stress than seedlings grown at PPFs <60 μmol·m-2·s-1. Fluorescent lamps alone (F) or fluorescent plus incandescent (F+I) lamps were compared for seedling responses to mechanical stress. Under F lighting, hypocotyl elongation was reduced 25% to 40% by twice-daily brush or plate treatments, and brushed seedlings exhibited more growth reduction than did plate treatments. Seedlings grown under F+I lamps exhibited similar stress-induced growth reduction compared to seedlings grown under F only, but stressed F+I seedlings lodged to a greater extent due to excessive hypocotyl elongation. Temperature-response studies using standardized F-only lighting indicated increased hypocotyl elongation but decreased leaf expansion, and decreased mechano-responsivity to brushing over the temperature range from 20 to 28 °C. Daylength studies indicated similar degrees of mechano-inhibition of hypocotyl elongation over the daylength range of 12, 16, 20, and 24 hours, whereas fresh weight of stressed seedling shoots declined compared to controls. A combination of environmental growth parameters that give repeatable, visual mechanical dwarfing of Arabidopsis include low-PPF fluorescent lighting from 55 to 60 μmol·m-2·s-1, ambient temperatures from 22 to 25 °C, and twice-daily brush treatments.
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Bigras, Francine. "Frost Tolerance of Black Spruce Seedlings (Picea Mariana) during Budbreak." HortScience 30, no. 4 (1995): 849C—849. http://dx.doi.org/10.21273/hortsci.30.4.849c.
Full textAbstract:
Spring frosts frequently cause significant damage to conifer seedlings during bud flushing and shoot elongation in forestry nurseries. To ensure adequate protection, levels of frost sensitivity must be known during these stages of development. Eight-month-old, containerized, black spruce seedlings were submitted to freezing temperatures of 0, –4, –6, –8, and –10C for 1, 2, 3, 4, 5, and 6 h at the following stages: 1) nonswollen buds; 2) swollen buds; 3) bud scales bursting, needle tips emerging; and 4) shoot elongation, 1 to 5 cm. After the treatments, seedlings were grown for 90 days in a greenhouse. Seedling survival then was estimated; dead seedlings discarded; and damage to buds, needles, and roots and shoot increment and diameter were measured on the remaining seedlings. Results show that frost sensitivity increases with the developing bud and shoot. A decrease in seedling and bud survival was noted with an increase in time of exposure (stages 2, 3, 4); otherwise, time exposure has no effect. Damage to needles and roots increases and diameter decreases with decreasing temperatures at all stages. Shoot increment was influenced by decreasing temperatures at stages 2 and 3 only.
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DeWald, Laura E., and Peter P. Feret. "Changes in loblolly pine root growth potential from September to April." Canadian Journal of Forest Research 17, no. 7 (1987): 635–43. http://dx.doi.org/10.1139/x87-104.
Full textAbstract:
Loblolly pine (Pinustaeda L.) 1 + 0 seedlings were periodically hand lifted from a Virginia nursery to determine how root growth potential (RGP) varied between September and April. Several seedling characteristics, RGP, and shoot phenology were recorded for each lift date in 1983–1984 and 1984–1985. An attempt was made to relate RGP variation to changes in the nursery environment and to shoot phenology. Root growth potential variation was consistent between years and was more closely related to shoot phenological changes than to short-term environmental changes. During the development of dormancy, RGP was low, RGP increased when shoot activity resumed during the RGP tests (late winter, early spring), and declined as active shoot elongation began in the nursery. When RGP was low, elongation of existing lateral roots primarily contributed to the new root systems, but as seedling metabolism increased in the late winter, new root initiation also contributed to new root systems. Absolute differences in RGP between years may be related to the fibrosity of seedling root systems.
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Mohapatra, P. M., A. R. Panda, and S. N. Ratho. "Inheritance study of seedling elongation in rice." International Rice Research Notes 23, no. 3 (1998): 9. https://doi.org/10.5281/zenodo.6947725.
Full textAbstract:
This article 'Inheritance study of seedling elongation in rice' appeared in the International Rice Research Notes series, created by the International Rice Research Institute (IRRI) to expedite communication among scientists concerned with the development of improved technology for rice and rice-based systems. The series is a mechanism to help scientists keep each other informed of current rice research findings. The concise scientific notes are meant to encourage rice scientists to communicate with one another to obtain details on the research reported.
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Van Gaal, Tami, and John E. Erwin. "Diurnal Variation in Thigmotropic Inhibition of Stem Elongation." HortTechnology 15, no. 2 (2005): 291–94. http://dx.doi.org/10.21273/horttech.15.2.0291.
Full textAbstract:
Wind, touching, and/or mechanical stress can restrict stem elongation. Removal of the registration of the growth retardant daminozide for use on edible crops increased interest in thigmotropic inhibition of stem elongation to control plant height in greenhouse crops, as well as a general desire by growers to decrease chemical inputs for floriculture crops. Since stem elongation varies diurnally, the question arises as to whether wind inhibition of stem elongation varies over a 24-hour period. Tomato (Lycopersicon esculentum) `MoneyMaker' and cosmos (Cosmos bipinnatus) `Imperial Pink' seedlings were placed under each of 10 wind perturbation treatments [applied for different durations and at different times during a 24-hour period; wind speed (perpendicular to the media) at seedling level was 30 km·h–1 (18.6 mph)] for 30 days. Data were collected on plant height and leaf number on days 1 and 30. The effect of wind on stem elongation differed with species; wind treatments restricted stem elongation more on cosmos than tomato (53% and 20%, respectively, across treatments). Tomato elongation was most restricted when seedlings received wind all day, all night, or all day and night. Within short-term treatments, internode length was least when tomato seedlings received a mid-day wind treatment. Cosmos elongation was most restricted when seedlings received a wind treatment all day or all night. Within short-term treatments, cosmos internode elongation was most restricted with early- and mid-day wind treatments. Data here suggest wind effects on elongation vary diurnally. In addition, the magnitude of wind effects on elongation varied with species and was greatest during the beginning of the day on cosmos, which mirrors when stem elongation is most sensitive to temperature fluctuations.
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Qin, Hua, Bipin K. Pandey, Yuxiang Li, et al. "Orchestration of ethylene and gibberellin signals determines primary root elongation in rice." Plant Cell 34, no. 4 (2022): 1273–88. http://dx.doi.org/10.1093/plcell/koac008.
Full textAbstract:
Abstract Primary root growth in cereal crops is fundamental for early establishment of the seedling and grain yield. In young rice (Oryza sativa) seedlings, the primary root grows rapidly for 7–10 days after germination and then stops; however, the underlying mechanism determining primary root growth is unclear. Here, we report that the interplay of ethylene and gibberellin (GA) controls the orchestrated development of the primary root in young rice seedlings. Our analyses advance the knowledge that primary root growth is maintained by higher ethylene production, which lowers bioactive GA contents. Further investigations unraveled that ethylene signaling transcription factor ETHYLENE INSENSITIVE3-LIKE 1 (OsEIL1) activates the expression of the GA metabolism genes GIBBERELLIN 2-OXIDASE 1 (OsGA2ox1), OsGA2ox2, OsGA2ox3, and OsGA2ox5, thereby deactivating GA activity, inhibiting cell proliferation in the root meristem, and ultimately gradually inhibiting primary root growth. Mutation in OsGA2ox3 weakened ethylene-induced GA inactivation and reduced the ethylene sensitivity of the root. Genetic analysis revealed that OsGA2ox3 functions downstream of OsEIL1. Taken together, we identify a molecular pathway impacted by ethylene during primary root elongation in rice and provide insight into the coordination of ethylene and GA signals during root development and seedling establishment.
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Pereira-Netto, Adaucto B., and Carmen L. O. Petkowicz. "A xyloglucan-induced increase in lettuce germination and seedling elongation is not related to the degradation of the exogenous xyloglucan." Botany 91, no. 12 (2013): 822–29. http://dx.doi.org/10.1139/cjb-2013-0099.
Full textAbstract:
Xyloglucans are the main hemicellulosic polysaccharides found in the primary cell walls of dicots and nongraminaceous monocots. Although xyloglucans are building blocks used in plant cell wall assembly, the function of these molecules in the structure and growth of the primary cell wall remains poorly understood. In this study, we demonstrate that treatment of lettuce seeds with a xyloglucan extracted from cotyledons of Hymenaea courbaril L. (Leguminosae (Fabaceae) – Caesalpinioideae) in the 0.1 to 10 nmol·L−1 range resulted in significantly increased germination percentage. In addition, lettuce seedlings grown in the presence of 500 nmol·L−1 xyloglucan presented a significantly larger length compared with seedlings grown in the absence of xyloglucan. Furthermore, the H. courbaril xyloglucan was not able to reverse a 2,4-dichlorophenoxy acetic acid induced inhibition of seedling elongation. High performance size exclusion chromatography (HPSEC) and high-performance liquid chromatography (HPLC) analyses indicated that the xyloglucan-induced enhancement of germination percentage and seedling elongation in lettuce does not rely on the release of monomers, i.e., glucose, xylose, and galactose from the exogenous xyloglucan.
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Liu, Qingqing, Zhijun Huang, Xiangqing Ma, et al. "Phenotypic Plasticity of Cunninghamialanceolata (Lamb.) Hook. Seedlings in Response to Varied Light Quality Treatments." Forests 13, no. 2 (2022): 201. http://dx.doi.org/10.3390/f13020201.
Full textAbstract:
Effects of light quality on phenotypic plasticity in Cunninghamialanceolata (Lamb.) Hook. seedlings during growth and development, and the underlying mechanisms, were investigated. The seedlings showed distinct morphological adjustments when exposed to an equal photosynthetic photon flux density (400 μmol·m−2·s−1) of different light qualities: monochromatic blue (BL), monochromatic red (RL), monochromatic far-red (FrL), mixed RL and FrL at 1:1 (RFr1:1L), mixed RL and FrL at 1:2 (RFr1:2L), and multi-wavelength white (WL, control). Compared with WL, FrL and BL significantly promoted height increment. However, BL was unfavorable for root growth. The seedling biomass was lower and the root-to-shoot ratio was smaller under BL. RL promoted leaf area enlargement, root growth, axillary bud number, and increased the root-to-shoot ratio, but inhibited stem elongation. Low R/Fr ratios or increased FrL proportion increased seedling stem elongation. The seedling growth under RFr1:1L treatment was poorer than that under other treatments; however, the number of axillary buds was the highest. The plasticity of leaf morphology traits was lower in different treatments, and that of axillary bud traits was crucial in the adaptation of C. lanceolata to light quality. Precise management of light quality and wavelength in controlled environments may maximize the economic efficiency of forest production and enhance its quality.
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Kemka, Ugochi, Etienne Chinakwe, and Emmanuel Egbadon. "Enhancement Potential of Plant Growth-Promoting Rhizobacteria on White Beans (Phaseolus vulgaris) Seedlings." International Letters of Natural Sciences 57 (August 2016): 11–17. http://dx.doi.org/10.18052/www.scipress.com/ilns.57.11.
Full textAbstract:
The effect of inoculating single cultures of plant growth-promoting rhizobacteria (PGPR) on development of white beans seedling (Phaseolus vulgaris) was analyzed. Five PGPR were isolated from the rhizosphere of Okra plants and were assessed for abilities to solubilise phosphate and produce indole acetic acid (IAA). The phosphate solubilising index ranged from 6-10 while the concentration of IAA ranged from 17.48mg/l to 27.43mg/l. Serratia sp. produced the highest concentration of IAA (27.43mg/l) and had the highest solubilisation index (10mm). Bacillus sp. produced the least amount of IAA (17.48mg/l) while Staphylococcus sp. had the least solubilisation index (6mm). The highest percentage germination of 83.3% was observed in the seedling inoculated with Bacillus sp. The influence of microbial inoculation on root and shoot elongation was studied hydroponically for 7 days. Significant increases (P< 0.05) in root elongation were observed. The highest seedling root length (18.47cm) and shoot length (19.17cm) were observed with inoculation of Staphylococcus sp. and Bacillus sp. respectively. The use of these bacteria as bio-inoculants could be a sustainable practice to facilitate nutrient supply to white beans seedlings.
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Kemka, Ugochi, Etienne C. Chinakwe, and Emmanuel Egbadon. "Enhancement Potential of Plant Growth-Promoting Rhizobacteria on White Beans (<i>Phaseolus vulgaris</i>) Seedlings." International Letters of Natural Sciences 57 (August 3, 2016): 11–17. http://dx.doi.org/10.56431/p-n4201z.
Full textAbstract:
The effect of inoculating single cultures of plant growth-promoting rhizobacteria (PGPR) on development of white beans seedling (Phaseolus vulgaris) was analyzed. Five PGPR were isolated from the rhizosphere of Okra plants and were assessed for abilities to solubilise phosphate and produce indole acetic acid (IAA). The phosphate solubilising index ranged from 6-10 while the concentration of IAA ranged from 17.48mg/l to 27.43mg/l. Serratia sp. produced the highest concentration of IAA (27.43mg/l) and had the highest solubilisation index (10mm). Bacillus sp. produced the least amount of IAA (17.48mg/l) while Staphylococcus sp. had the least solubilisation index (6mm). The highest percentage germination of 83.3% was observed in the seedling inoculated with Bacillus sp. The influence of microbial inoculation on root and shoot elongation was studied hydroponically for 7 days. Significant increases (P< 0.05) in root elongation were observed. The highest seedling root length (18.47cm) and shoot length (19.17cm) were observed with inoculation of Staphylococcus sp. and Bacillus sp. respectively. The use of these bacteria as bio-inoculants could be a sustainable practice to facilitate nutrient supply to white beans seedlings.
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Vergara, Georgina, and Abdelbagi Ismael. "Development and Characterization of Rice Lines Carrying both Sub1 and Anaerobic Germination Tolerance: SUB1A does not Inhibit AG [RESEARCH NOTE]." Philippine Agricultural Scientist 106, no. 3 (2023): 330–37. http://dx.doi.org/10.62550/dcd038023.
Full textAbstract:
Accelerated coleoptile elongation in flooded soils allowed seedling shoots to reach the water surface to maintain gas exchange and CO2 fixation. Rice genotypes with tolerance of flooding during germination (anaerobic germination, AG) exhibited fast coleoptile elongation as an escape mechanism. On the other hand, tolerance of complete submergence during the vegetative stage, conferred by SUB1A, involved growth retardation to conserve energy for maintenance metabolism, with resumption of growth upon de-submergence. Combining genes controlling flood tolerance at these two stages with contrasting mechanisms was necessary in flood-prone areas for protection during germination under direct seeding and during vegetative stage. Breeding lines combining AG + Sub1 were used to determine the timing of the expression of SUB1A and elucidate its impact when combined with tolerance of flooding during seed germination and to evaluate seedling performance under complete submergence. Time-points for SUB1A expression in IR64-Sub1 and AG + Sub1 lines germinated under hypoxia or submerged for 30 h at vegetative stage showed that during flooding treatment, SUB1A and SUB1C expression was inhibited in young seedlings (< 6 d old) in IR64-Sub1 and at 2 and 4 d of seedling growth under hypoxia in AG + Sub1 materials. SUB1A was weakly expressed in AG + Sub1 starting at seedling age of 6 d following 1 d of complete submergence, indicating that expression of SUB1A may be stage-specific. Physiological tests showed higher percentage of survival of AG + Sub1 lines under hypoxia, comparable to that of AG tolerant check and significantly different from intolerant check IR42, indicating that the presence of SUB1A does not affect tolerance of flooding during germination. When seedlings were completely submerged, Sub1 expression was not inhibited by the presence of AG and tolerant genotypes showed suppressed elongation that was significantly different from intolerant check IR42. Despite their contrasting mechanisms of tolerance, combining AG with Sub1 provides multiple flooding tolerance from early crop establishment using direct seeding through to the vegetative stages.
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Williamson, Jeffrey G., Karen E. Koch, and William S. Castle. "CITRUS ROOTSTOCK SHOOTS ENHANCE SCION GROWTH AFTER BUD FORCING." HortScience 25, no. 9 (1990): 1152d—1152. http://dx.doi.org/10.21273/hortsci.25.9.1152d.
Full textAbstract:
Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.] seedlings were budded with `Hamlin' orange [Citrus sinensis (L.) Osb.] and subjected to 3 bud forcing treatments: (1) topping [T] by removing the seedling above the bud union; (2) lopping [L] by cutting half way through the seedling above the bud union and breaking the rootstock over; or, (3) bending [B] the seedling top over and tying it to the base of the plant. As scion buds emerged and grew, plants were sacrificed for dry weight measurements; also, the portion of the rootstock seedling above the bud union was exposed to 14CO2 at 3 stages of scion development. Plants with seedling tops attached (B,L) gained more dry weight and fibrous roots than T seedlings. Scion elongation was greater for B plants than for T plants. Plants usually flushed twice regardless of bud forcing treatment. No treatment differences were noted for time of flushing or scion bud emergence. Labeled photosynthate from attached rootstock leaves was translocated to scions during both flushes suggesting that recently fixed C enhanced scion growth for B and L plants.
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Zhao, Xiaoqiang, Jiayao Li, Yining Niu, et al. "Exogenous Serotonin (5-HT) Promotes Mesocotyl and Coleoptile Elongation in Maize Seedlings under Deep-Seeding Stress through Enhancing Auxin Accumulation and Inhibiting Lignin Formation." International Journal of Molecular Sciences 24, no. 23 (2023): 17061. http://dx.doi.org/10.3390/ijms242317061.
Full textAbstract:
Serotonin (5-HT), an indoleamine compound, has been known to mediate many physiological responses of plants under environmental stress. The deep-seeding (≥20 cm) of maize seeds is an important cultivation strategy to ensure seedling emergence and survival under drought stress. However, the role of 5-HT in maize deep-seeding tolerance remains unexplored. Understanding the mechanisms and evaluating the optimal concentration of 5-HT in alleviating deep-seeding stress could benefit maize production. In this study, two maize inbred lines were treated with or without 5-HT at both sowing depths of 20 cm and 3 cm, respectively. The effects of different concentrations of 5-HT on the growth phenotypes, physiological metabolism, and gene expression of two maize inbred lines were examined at the sowing depths of 20 cm and 3 cm. Compared to the normal seedling depth of 3 cm, the elongation of the mesocotyl (average elongation 3.70 cm) and coleoptile (average elongation 0.58 cm), secretion of indole-3-acetic acid (IAA; average increased 3.73 and 0.63 ng g−1 FW), and hydrogen peroxide (H2O2; average increased 1.95 and 0.63 μM g−1 FW) in the mesocotyl and coleoptile were increased under 20 cm stress, with a concomitant decrease in lignin synthesis (average decreased 0.48 and 0.53 A280 g−1). Under 20 cm deep-seeding stress, the addition of 5-HT activated the expression of multiple genes of IAA biosynthesis and signal transduction, including Zm00001d049601, Zm00001d039346, Zm00001d026530, and Zm00001d049659, and it also stimulated IAA production in both the mesocotyl and coleoptile of maize seedlings. On the contrary, 5-HT suppressed the expression of genes for lignin biosynthesis (Zm00001d016471, Zm00001d005998, Zm00001d032152, and Zm00001d053554) and retarded the accumulation of H2O2 and lignin, resulting in the elongation of the mesocotyl and coleoptile of maize seedlings. A comprehensive evaluation analysis showed that the optimum concentration of 5-HT in relieving deep-seeding stress was 2.5 mg/L for both inbred lines, and 5-HT therefore could improve the seedling emergence rate and alleviate deep-seeding stress in maize seedlings. These findings could provide a novel strategy for improving maize deep-seeding tolerance, thus enhancing yield potential under drought and water stress.
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Radford, BJ, and RG Henzell. "Temperature affects the mesocotyl and coleoptile length of grain sorghum genotypes." Australian Journal of Agricultural Research 41, no. 1 (1990): 79. http://dx.doi.org/10.1071/ar9900079.
Full textAbstract:
The effect of seven temperatures ranging from 15 to 45�C on the germination and seedling length (mesocotyl +coleoptile) of eight grain sorghum genotypes (QL10, QL27, B35, R9247, BTx2761, BKS4, RTx7078 and 1790E) was determined. There was significant variation in germination (25-100%) and seedling length (6-182 mm) across temperatures and among genotypes, and significant temperature X genotype interactions occurred. Emergence problems due to poor germination and inadequate seedling length are likely in certain genotypes at high (>30�C) and low (<20�C) seedbed temperatures, particularly when deep sowing is necessary to reach moist soil. The optimum temperature for coleoptile elongation was 15-20�C, while the optimum for mesocotyl elongation varied from 15-30�C. Generally, the coleoptile comprised only a small proportion of the total seedling length, but the proportion increased at high and low temperatures (range: 6-53% of seedling length). The mesocotyl lengths of five genotypes selected at ICRISAT for their long mesocotyls were not outstanding compared with a locally derived hybrid B35 X R9247, which had not been selected for long mesocotyls. It is recommended that commercial hybrids be screened for germination and seedling elongation at the temperatures that occur in the seedbed at sowing.
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Jones, R. W., L. M. Pike, and L. F. Yourman. "Salinity Influences Cucumber Growth and Yield." Journal of the American Society for Horticultural Science 114, no. 4 (1989): 547–51. http://dx.doi.org/10.21273/jashs.114.4.547.
Full textAbstract:
Abstract Germination and radicle elongation experiments were performed with six cultivars of cucumber (Cucumis sativus L.) at seven salinity concentrations (0, 0.8, 4.0, 6.0, 9.0, 12, and 15 dS·m−1). Increasing salinity has no effect on final germination percentage after 5 days, but did decrease radicle elongation. In seedling growth studies with salinity levels ranging from 0.8 to 12 dS·m−1, increasing salt levels decreased shoot length and shoot dry weight. Analysis of shoot tissue from these seedlings indicated that higher salinity levels increased concentrations of Ca and Na, while Mg and K concentrations decreased. Yield and fruit quality were measured in a greenhouse study at two salinity levels (1.6 and 4.0 dS· m−1). Salinity significantly decreased fruit yield in five of six cultivars, but had no effect on fruit quality. Seedling shoot length of a cultivar grown at 9.0 dS· m−1 was correlated with relative yield at 4.0 dS· m−1. A salinity screening technique based on this relationship is proposed.
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Jurišić-Knežev, Dejana, Mária Čudejková, David Zalabák, et al. "Maize AUXIN-BINDING PROTEIN 1 and AUXIN-BINDING PROTEIN 4 impact on leaf growth, elongation, and seedling responsiveness to auxin and light." Botany 90, no. 10 (2012): 990–1006. http://dx.doi.org/10.1139/b2012-071.
Full textAbstract:
In maize, at least five auxin-binding proteins (ABPs) have been identified, yet their functions remain unclear. The present study reports the use of maize abp1, abp4, and abp1abp4 mutants to investigate the role of ABPs during maize growth and development. Single and double abp mutant plants grown in a greenhouse differ from the wild type (WT) in their leaf declination and leaf blade growth. The effect of the dark (D), blue light (BL), red light (RL), and exogenous auxin on the development of mutant seedlings was also studied. Relative to WT, etiolated mutant seedlings were shorter and showed a reduced responsiveness to exogenous auxin. In BL or RL, the responsiveness of maize seedlings to auxin was distinctly less than in D. The reducing effect of light on seedling responsiveness to auxin is mediated at least by phytochromes. The suppression of ABP1 and (or) ABP4 led to a distinct accumulation of free indole-3-acetic acid (IAA) in etiolated and light-grown seedling organs. We concluded that ABP1 and ABP4 participate in the growth of maize seedlings, mediate seedling responses to auxin, and interact with light signaling pathway(s). We also deduce a functional interaction between ABP1 and ABP4, which is that the relationship between them is light-, organ- and response-dependent.
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Yun, Kyeong W., and M. A. Maun. "Allelopathic potential of Artemisia campestris ssp. caudata on Lake Huron sand dunes." Canadian Journal of Botany 75, no. 11 (1997): 1903–12. http://dx.doi.org/10.1139/b97-902.
Full textAbstract:
Greenhouse studies were conducted to test allelopathic effects of Artemisia campestris ssp. caudata on seed germination and seedling growth of several sand-dune species and colonization by mycorrhizal fungi. The aqueous extracts of A. campestris showed no inhibitory effect on seed germination, seedling elongation, or dry-weight growth of plants at lower concentrations (10 and 50%), but 100% concentration of the extracts caused varying degrees of inhibition depending on the test species. The mixing of dry leaves of seedlings of A. campestris to the sand showed severe inhibition of Elymus canadensis seedlings. The percent germination of test species in soil from the rhizosphere of A. campestris was significantly lower than that of the control. The leaf area and dry weight were also lower but the differences were not significant. The aqueous extract inhibited mycorrhizal fungal colonization in roots of three sand-dune grasses. Key words: allelopathy, Artemisia campestris ssp. caudata, seed germination, seedling growth, mycorrhizal fungi.
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Burnett, Stephanie, Paul Thomas, and Marc van Iersel. "Postgermination Drenches with PEG-8000 Reduce Growth of Salvia and Marigolds." HortScience 40, no. 3 (2005): 675–79. http://dx.doi.org/10.21273/hortsci.40.3.675.
Full textAbstract:
We previously found that incorporation of PEG-8000 into the growing medium delayed germination and resulted in shorter seedlings. However, in that study, we were unable to determine whether the reduced height was merely the effect of delayed germination or of reduced elongation after germination. To answer this question, we studied whether postgermination drenches with PEG-8000 can reduce seedling height. Annual salvia (Salvia splendens F. Sellow. ex Roem. & Shult. `Bonfire') and French marigold (Tagetes patula L. `Boy Orange') seedlings were treated with drenches of PEG-8000: 0, 15, 20, 30, 42, 50, 62, 72, or 83 g·L–1. At least 20% of seedlings treated with 62 to 83 g·L–1 of PEG-8000 were dead 14 d after treatment. Salvia and marigolds treated with the remaining PEG-8000 concentrations were up to 34% and 14% shorter than untreated seedlings, respectively. Leaf water (Ψw) and turgor potential (Ψp) also decreased for salvia which were grown with greater concentrations of PEG-8000, one probable cause of the observed reduction in elongation. Since the PEG-8000 in this study was applied after germination, it is clear that PEG-8000 does not reduce elongation merely by delaying germination, but also by reducing the elongation rate. Thus, postgermination drenches with PEG-8000 can be used to produce shorter seedlings.
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Mas, M. T., and A. M. C. Verdú. "Mesocotyl elongation in Digitaria sanguinalis during seedling development." Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology 150, no. 6 (2015): 1175–81. http://dx.doi.org/10.1080/11263504.2015.1009189.
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Seiwa, Kenji, and Kihachiro Kikuzawa. "Phenology of tree seedlings in relation to seed size." Canadian Journal of Botany 69, no. 3 (1991): 532–38. http://dx.doi.org/10.1139/b91-072.
Full textAbstract:
Vertical growth patterns and leaf dynamics of seedlings of 31 deciduous broad-leaved tree species with different seed sizes were examined under either open or shaded conditions. Seed size positively affected initial seedling height and leaf longevity, and negatively affected duration of leaf emergence and leaf-turnover rate. Large-seeded species completed shoot elongation and almost all of their annual leaf production in a short period, irrespective of shading. Small-seeded species attained maximum heights similar to those of large-seeded species under open conditions by having a longer duration of leaf emergence, higher resource allocation to leaf production, and rapid leaf turnover. However, leaf-production and leaf-turnover rates were reduced by shading for small-seeded species, a trait that resulted in lower final seedling heights for small- versus large-seeded species. In small-seeded species, maximum seedling growth was attained only under open conditions through changes in the phenology of leaf dynamics. In contrast, growth of large-seeded species was independent of the effect of light limitation. The importance of seed size in determining seedling establishment success depends on the relationships between seasonal change of environmental light conditions and characteristics of seedling phenology, which are related to seed size. Key words: seed size, tree seedlings, leaf dynamics, phenology, establishment strategies.
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Magnitskiy, Stanislav V., Claudio C. Pasian, Mark A. Bennett, and James D. Metzger. "Controlling Plug Height of Verbena, Celosia, and Pansy by Treating Seeds with Paclobutrazol." HortScience 41, no. 1 (2006): 158–61. http://dx.doi.org/10.21273/hortsci.41.1.158.
Full textAbstract:
Shoot stretching in plug production reduces quality and makes mechanized transplanting difficult. The objectives of this study were to measure seedling emergence and shoot height of plugs as affected by paclobutrazol application during seed soaking, priming, or coating on seedling emergence and height. Verbena (Verbena ×hybrida Voss. `Quartz White'), pansy (Viola wittrockiana L. `Bingo Yellow Blotch'), and celosia (Celosia cristata L. `New Look') seeds were soaked in water solutions of paclobutrazol and subsequently dried on filter paper at 20 °C for 24 h. Soaking seeds in paclobutrazol solutions before sowing reduced growth and percentage seedling emergence of verbena and pansy but had little effect on those of celosia. Verbena seeds soaked in 50, 200, or 500 mg paclobutrazol/L for 5, 45, or 180 min produced fewer and shorter seedlings than controls. Osmopriming verbena seeds with 10 to 500 mg paclobutrazol/L reduced seedling emergence. Seedling height and emergence percentage of pansy decreased with increasing paclobutrazol concentrations from 2 to 30 mg·L–1 and with soaking time from 1 to 5 min. The elongation of celosia seedlings was reduced by soaking seeds in 10, 50, 200, or 500 mg paclobutrazol/L solutions for 5, 180, or 360 min. However, these reductions were negligible and without any practical application.
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Radford, BJ, and AJ Key. "Temperature affects germination, mesocotyl length and coleoptile length of oats genotypes." Australian Journal of Agricultural Research 44, no. 4 (1993): 677. http://dx.doi.org/10.1071/ar9930677.
Full textAbstract:
Seedlings of 16 oats genotypes (Algerian, Amby, Bulban, Cluan, Culgoa, Echidna, MA5030, Minhafer, Moore, Mortlock, Panorama 5, Riel, Saia, Stout, West and 81Ab1063) were allowed to elongate in darkness at six constant temperatures (10, 15, 20, 25, 30 and 35�C) to determine the effect of temperature on final mesocotyl and coleoptile length. The optimum temperature for maximum mesocotyl+coleoptile length (potential maximum sowing depth) was 15�C. Potential sowing depth at 10 to 25�C was always large (113 to 252 mm) but there was a decline with increase in temperature above 20�C. The decline was due to reduced coleoptile length rather than reduced mesocotyl length. Temperaturexgenotype interactions were significant (P < 0.01) but all cultivars showed a similar general trend in response to temperature. Shoots, but not necessarily the primary roots, failed to emerge from the seeds of any genotype at a constant temperature of 35�C. When the temperature was subsequently reduced to 20�C, however, shoot emergence took place. Poor field emergence of early sowings may be related to such temporary cessation of the germination process at high temperatures. Reduced seedling elongation at high temperature may also be involved. The wide variation at 30�C in germination percentage (8 to 100%) and seedling elongation (55 to 126 mm) suggested a genetic solution to the problem of poor emergence at moderately high soil temperatures. Germination and seedling elongation at 30�C were postively correlated. There were no significant (P > 0.05) correlations between mature plant height or seed weight with mesocotyl length, coleoptile length or potential maximum sowing depth.
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Addae, PC, and CJ Pearson. "Thermal requirement for germination and seedling growth of wheat." Australian Journal of Agricultural Research 43, no. 3 (1992): 585. http://dx.doi.org/10.1071/ar9920585.
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Two cultivars of wheat, Hartog (a spring type) and Rosella (winter) were sown at 2, 5, 8, 10, 15, 20 and 25�C on porous sand medium held at constant soil matric potential. The thermal times required for germination, onset of coleoptile elongation and emergence were similar, 27, 35 and 130�C days respectively, for the two cultivars over the temperature range of 2-25�C. By extrapolation, the base temperature for germination and coleoptile elongation was 1�C and for emergence 0.4�C. The rate of seedling elongation and emergence of both cultivars increased linearly with temperature between 5 and 25�C. Final percentage germination, final coleoptile length and total emergence of both cultivars were independent of temperature between 8 and 25�C but were smaller at 2�C. Differences between the two cultivars were confined to response to low temperature (2OC) during germination and to high temperature (25�C) during coleoptile elongation.
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Bridgwater, Floyd E. "Shoot Elongation Patterns of Loblolly Pine Families Selected for Contrasting Growth Potential." Forest Science 36, no. 3 (1990): 641–56. http://dx.doi.org/10.1093/forestscience/36.3.641.
Full textAbstract:
Abstract Ten half-sib families of loblolly pine chosen to represent a wide range of size in 8-year-old field trials, exhibited different shoot elongation patterns during their second year in retrospective seedling trials. In all but two families, the different patterns of annual shoot elongation were consistent in irrigated and nonirrigated treatments. Two families that ranked high for growth rate in the 8-year-old field trials also had greater annual shoot growth in the seedling trial without irrigation, but performed poorer than expected when well watered. The different patterns in annual height increment arose as a consequence of changes in the relative contributions of numbers of stem units, the average shoot length per stem unit, and the percentage of trees elongating. However, total annual height increment produced during the second year was a better predictor of the size of half-siblings after 8 years in field trials than any of the components of shoot growth. Families with greater size after 8 years in field trials had longer annual leaders in the seedling trial, but for varying reasons. Some were longer primarily because they had more stem units, while others had average numbers of stem units but greater-than-average stem unit lengths. The percentage of trees elongating near the end of the season was of little or no importance in determining the relative ranks of families within each of two geographic populations studied, but contributed to the differences between the two populations. For. Sci. 36(3):641-656.
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Akter, Nousin Akter, and Md Hasanur Rahman Rahman. "Assessment of Aqueous Leaf Extracts of Parthenium Hysterophorus L. On Seedlings Growth of Wheat." Journal of Bio-Science 31, no. 1 (2023): 61–70. http://dx.doi.org/10.3329/jbs.v31i1.69535.
Full textAbstract:
An investigation was conducted to assess the effect of Parthenium hysterophorus L. leaf extracts on seedling growth of three wheat (Triticum aestivum L.) varieties viz. Sourav, BARI Gom 22 and BARI Gom 33. It was observed that the growth of wheat seedlings was significantly influenced by the Parthenium extract treatments. BARI Gom 22 showed more tolerance to Parthenium treatments than BARI Gom 33 and Sourav. Generally, wheat seedlings growth was inhibited by Parthenium extract treatments at all periods. The percent inhibition of shoot and root elongation were more visible at 5% treatment concentration at all periods than other extract treatments. On the other hand the number of root of wheat seedlings was not found to be affected by Parthenium at 7 and 10-day periods. It was also noted that the effect of Parthenium extracts on wheat seedling growth is concentrations dependent manner. J. Bio-Sci. 31(1): 61-70, 2023