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Journal articles on the topic 'Seedling stages'
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1
Pedroza Carneiro, José Walter. "Stevia rebaudiana (Bert.) Bertoni: Stages of plant development." Canadian Journal of Plant Science 87, no. 4 (2007): 861–65. http://dx.doi.org/10.4141/p06-040.
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Vegetative and reproductive codes were developed to describe seeds under germination, normal seedlings, seedling growth, plant growth and branching, plant regrowth, flower buds, crop flowering (anthesis), developing seeds, seed dispersion, and senescent plants as V0, V1.i, V2.i, V3.i.k, V4.i.k, R1.i, R2.i, R3.i, R4.i and R5.i, respectively. The numerical code attached to both capital letters indicates the stage, and the lower case letters i or k indicate a number or a percentage. Key words: Natural sweetener, plant regrowth, anthesis, seed, seedling, transplant
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Ratnayake, Sunil, and David R. Shaw. "Effects of Harvest-Aid Herbicides on Sicklepod (Cassia obtusifolia) Seed Yield and Quality." Weed Technology 6, no. 4 (1992): 985–89. http://dx.doi.org/10.1017/s0890037x00036587.
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Experiments were conducted in 1989 and 1990 to study the effects of 220 g ai ha-1AC 263,222, 840 g ai ha-1glufosinate, 560 g ai ha-1glyphosate, and 840 g ai ha-1paraquat on sicklepod seed production and quality when applied at R5, R6, R7, and R8 growth stages of sicklepod. No seed were produced on plants treated at R5 with paraquat and glufosinate; glyphosate was the least effective herbicide at this growth stage. Although sicklepod seed germinated after AC 263,222 application at R5, no seedling emergence occurred. Normal seedlings, seedling emergence, and seedling radicle length were reduced by all herbicides applied to parent plants at R5, R6, and R7 growth stages. AC 263,222 applied at R7 reduced normal seedlings and seedling emergence more than any other herbicide. No effects were observed on any of the variables investigated when herbicides were applied at R8.
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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.
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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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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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Moe, Roar, John E. Erwin, and Will Carlson. "Factors Affecting Gerebera jamesonii Early Seedling Branching and Mortality." HortTechnology 6, no. 1 (1996): 59–61. http://dx.doi.org/10.21273/horttech.6.1.59.
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The role of irradiance and/or ethylene in inducing mortality and self-branching disorders in Gerbera jamesonii Bolus. seedlings was studied. Seedling mortality increased from 8% to 57% when seed was covered with vermiculite than left uncovered during germination. Supplemental lighting for 30 days after germination decreased seedling mortality and decreased the time to visible bud compared to seed germinated under natural light only. In subsequent experiments, seeds were germinated and then seedlings were water logged or sprayed with ethephon (0.69, 3.45, or 17.25 mM) at four different stages of seedling development. Half of the ethephon-treated seedlings were sprayed with silver thiosulfate (STS). Seedling mortality was greatest after cotyledon expansion but before expansion of the first tree leaf. The highest ethephon concentration caused reduced seedling dry weight after 42 days. Applying STS did not overcome self-branching or meristem necrosis.
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Edelman, Nichole F., and Michelle L. Jones. "Evaluating Ethylene Sensitivity within the Family Solanaceae at Different Developmental Stages." HortScience 49, no. 5 (2014): 628–36. http://dx.doi.org/10.21273/hortsci.49.5.628.
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The family Solanaceae, which includes both important crop and ornamental species, is generally considered to have high sensitivity to ethylene. Our objectives were to evaluate ethylene sensitivity between accessions with the family Solanaceae and to determine whether similar sensitivity was observed in seedlings and mature plants. For the seedling evaluations, seeds were germinated and grown in the dark on filter paper saturated with 0 or 100 μM 1-aminocyclopropane-1-carboxylic acid (ACC; the immediate precursor to ethylene). The relative hypocotyl length at 100 μM ACC was compared with untreated control (0 μM) seedlings. Mature plants were treated with 0 or 10 μL·L−1 ethylene in the dark for 24 hours. Ethylene responses including flower abscission, flower senescence, and epinasty were observed and quantified. Seedlings and mature plants were classified as having no response, low, medium, or high ethylene sensitivity based on the severity of the ethylene responses observed. Sensitivity differences were observed among seedling, juvenile, and mature plants, and a range of ethylene responses and symptom severity was observed between accessions within a species. The majority of the accessions were classified as medium or high ethylene sensitivity at both the seedling and mature plant stages. Solanum melongena ‘Black Beauty’ (eggplant) had a low response to ethylene at the seedling stage and a high response at the mature plant stage, whereas Petunia ×hybrida ‘Daddy Orchid’ had a high response at the seedling stage and a low response at the mature plant stage. Peppers (Capsicum annum), tomatoes (Solanum lycopersicum), and tomatillos (Physalis ixocarpa) exhibited both floral and vegetative symptoms of ethylene damage, whereas calibrachoas (Calibrachoa ×hybrida), eggplants, nicotianas, and petunias exhibited only floral symptoms. The most common floral response to ethylene treatment was flower abscission, which was observed in almost all of the Solanum, Capsicum, and Nicotiana accessions. We consistently observed ethylene-induced epinasty in the genus Capsicum and in all of the Solanum except eggplant. Our results indicated that developmental stage influenced ethylene sensitivity, and there was not a consistent correlation between seedling and mature plant responses within the Solanaceae accessions that we evaluated.
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Pannwitt, Heike, Paula R. Westerman, Friederike De Mol, and Bärbel Gerowitt. "Demographic Processes Allow Echinochloa crus-galli to Compensate Seed Losses by Seed Predation." Agronomy 11, no. 3 (2021): 565. http://dx.doi.org/10.3390/agronomy11030565.
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The effect of weed management that targets the seed stage on subsequent life stages is largely unknown. Post-dispersal seed predation reduces the number of seeds from the soil surface before the seeds contribute to the seedbank. Density-dependent processes can mitigate the effect of seed predation in subsequent life stages. In this study, we tested if (i) targeting the seed stage affects the subsequent seedling stage; (ii) if density-dependent mortality in subsequent life stages partly compensates seedling abundance; and (iii) if the magnitude of final seed production depends on seed predation. We fully parameterized a model for the summer-annual weed Echinochloa crus-galli (L.) P. Beauv. Field data from three maize fields in north-eastern Germany were obtained, in the presence or absence of seed predation and different population levels of the weed species. Seeds of E. crus-galli were applied in autumn and the number of seedlings, adult plants, and seed production per m2 was determined the following season. Seed predation reduced the number of seedlings. Density-dependent mortality during the seedling stage increased fecundity with decreasing seedling density, and, thus, compensated for lower numbers of seedlings. The final level of seed production per m2 did not depend on seed predation and initial population densities, but differed among fields. We conclude, solely targeting the seed stage can scarcely limit the population growth of E. crus-galli.
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Erniwati, Erniwati. "PENGARUH UKURAN BIJI TERHADAP KEMAMPUAN TANAMAN TUMBUH KEMBALI SETELAH RUSAK AKIBAT HERBIVORI." Jurnal Ilmu-Ilmu Pertanian Indonesia 9, no. 2 (2017): 156–64. http://dx.doi.org/10.31186/jipi.9.2.156-164.
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The objective of the study is to investigate the effect of seed size in the resprouting ability of seedling after being damaged and whether it correlates with the reserve effect. We grew the seedlings of two species of oak, namely Quercus robur and Quercus petraea from different seed size, in a greenhouse. The seedlings were harvested at different stages; after emergence, at the first shoot fully developed, and after the seedling had re- grown after the initial shoot was clipped. The result showed that: firstly, at the time of full seedling development, large seeds translocated less percentage of reserve from the seed to seedling. After clipping, the seedlings from large seeds translocated additional resources to the seedling. Secondly, although the larger seed has the larger biomass to re-sprout, the total mass invested in re-sprouting proportional with seedling size. We concluded that the seedlings of larger seeds re-sprout better than those of the smaller seeds. However, we did not find the improved performances correlating with the Reserve Effect Theory
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Li, Qiang, Pujia Yu, Xiaoying Chen, Guangdi Li, Daowei Zhou, and Wei Zheng. "Facilitative and Inhibitory Effect of Litter on Seedling Emergence and Early Growth of Six Herbaceous Species in an Early Successional Old Field Ecosystem." Scientific World Journal 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/101860.
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In the current study, a field experiment was conducted to examine effects of litter on seedling emergence and early growth of four dominant weed species from the early successional stages of old field ecosystem and two perennial grassland species in late successional stages. Our results showed that increased litter cover decreased soil temperature and temperature variability over time and improved soil moisture status. Surface soil electrical conductivity increased as litter increased. The increased litter delayed seedling emergence time and rate. The emergence percentage of seedlings and establishment success rate firstly increased then decreased as litter cover increased. When litter biomass was below 600 g m−2, litter increased seedlings emergence and establishment success in all species. With litter increasing, the basal diameter of seedling decreased, but seedling height increased. Increasing amounts of litter tended to increase seedling dry weight and stem leaf ratio. Different species responded differently to the increase of litter.Puccinellia tenuifloraandChloris virgatawill acquire more emergence benefits under high litter amount. It is predicted thatChloris virgatawill dominate further in this natural succession old field ecosystem with litter accumulation. ArtificialP. tenuifloraseeds addition may be required to accelerate old field succession toward matured grassland.
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Khalid S. Alshallash, Khalid S. Alshallash. "Biological Control of the Weedy Plant (Rumex crispus) at the Seedling Growth Stage by the Green Dock Beetle (Gastrophysa viridula)." journal of King Abdulaziz University - Meteorology, Environment and Arid Land Agriculture Sciences 28, no. 1 (2019): 21–31. http://dx.doi.org/10.4197/met.28-1.3.
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In four glasshouse experiments, the effectiveness of the adult green dock beetle Gastrophysa viridula (Coleoptera: Chrysomelidae), at the effective number of applied individuals, for use as a biological control agent of curled dock, Rumex crispus (Polygonaceae) were studied. The feeding of the beetle was investigated at four different numbers of beetle (0, 1, 2, 3) and at four seedling growth stages of the plant, defined by the average of leaf area per plant (1-1.22 , 2-4.45, 3-11.56, and 4-71.52 cm2/plant). Grazing by one, two or three dock beetles did not result in a significant reduction in dock dry weight or shoot numbers at the youngest growth stage. However, both at later seedling growth stages were significantly affected (P ? 0.0001), at any beetles number. The increase of beetle numbers caused nonsignificant increased effect, in some trials, confirming the impact of a single beetle. Three months after beetle grazing, dock seedlings of first, second and third growth stages were not able to regrow, however, some plants at the 4th growth stage, re-emerged. This suggested that the highest effect of beetle's feeding occurs on the early seedling stages. Statistical analysis showed a positive correlation (0.77) between dry weight and shoot number at all the four seedling growth stages, thus confirming the impact of the beetle on both the dry weight and shoot numbers. Combining beetle grazing with other control methods at older dock seedling stages could, therefore, provide better suppression
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Lorca, E. Agostina, Ana E. Ferreras, and Guillermo Funes. "Seed size and seedling ontogenetic stage as modulators of damage tolerance after simulated herbivory in a woody exotic species." Australian Journal of Botany 67, no. 2 (2019): 159. http://dx.doi.org/10.1071/bt18093.
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Herbivory is one of the most important threats that plants face during early stages of development. Previous studies have indicated that seed size and seedling ontogeny strongly influence the response to herbivory at the seedling stage. However, little is known about their interactive effect. We simulated herbivory on seedlings of the exotic Gleditsia triacanthos L. and evaluated the combined effects of seed size and ontogenetic stage at which herbivory occurred on tolerance to herbivory. A greenhouse experiment was performed, with three non-overlapping levels of seed size. Seedlings from each seed size were clipped at two ontogenetic stages (two and five leaves). After three weeks, seedling survival, height, leaf number and dry biomass were measured. Damaged seedlings were not able to reach the size of the undamaged ones. Seedlings from small seeds showed the lowest values in most of the growth variables. Seedlings cut at two-leaf stage showed a higher compensation capacity than those cut at five-leaf stage. Seedlings from large seeds cut at ontogenetic stage I showed the highest compensation capacity in most of the variables. Partly compensating herbivory at this stage may be an advantage for the expansion of this exotic species to new areas.
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Oka, Chihiro, Tomoyuki Itagaki, and Satoki Sakai. "Effects of the number of embryos in a seed and seed mass on seedling survival and growth in polyembryonic Ophiopogon japonicus var. umbrosus (Asparagaceae)." Botany 94, no. 4 (2016): 261–68. http://dx.doi.org/10.1139/cjb-2015-0214.
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Research on polyembryony suggests that the presence of multiple embryos in a seed confers an advantage for seedling survival. Because observations from embryo to seedling stages are lacking, however, the effect of the exact number of embryos on seedling survival is unclear. In this study, we evaluated the effect of seed embryo number on seedling survival and growth to determine the number of embryos in a seed that are advantageous for seedling survival in Ophiopogon japonicus (Thunb.) Ker Gawl. var. umbrosus Maxim., which is a taxon exhibiting cleavage polyembryony. We also investigated whether seed mass affects seed embryo number and seedling survival and growth. We found that the number of embryos in seeds of O. japonicus var. umbrosus was weakly dependent on seed mass. As the number of embryos increased, the number of seedlings surviving from seeds initially increased and then decreased; the greatest number of seedlings was produced from an intermediate number of embryos, with the number of embryos producing the greatest number of seedlings increasing with seed mass. The sum of individual seedling lengths increased with the number of seedlings. Our results indicate that an intermediate number of embryos may be advantageous in polyembryonic O. japonicus var. umbrosus.
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Cong Dien, Doan, and Takeo Yamakawa. "Phenotypic Variation and Selection for Cold-Tolerant Rice (Oryza sativa L.) at Germination and Seedling Stages." Agriculture 9, no. 8 (2019): 162. http://dx.doi.org/10.3390/agriculture9080162.
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Owing to its origin in tropical and subtropical areas, rice is susceptible to cold stress. Low temperatures at the germination and seedling stages can result in seed loss, a delayed transplanting period, and lower final yield. In this study, 181 rice varieties from around the world were investigated for cold tolerance at the germination and seedling stages. At the germination stage, the responses of different rice varieties were examined based on the germination index, coleoptile length, and radicle length at low (13 °C) and control temperatures (25 °C). Significant variations in the germination index, coleoptile length, and radicle length were observed among varieties. Low temperature significantly decreased germination ability, and coleoptile and radicle growth in the studied varieties. At the seedling stage, cold tolerance of the rice varieties was evaluated based on the leaf color score under natural low temperature. Similar to the germination stage, at the seedling stage, significant variation in root and shoot growth was observed in the response of rice varieties to low temperature conditions. Based on the results from both the germination and seedling stages, two varieties (Hei-Chiao-Chui-Li-Hsiang and Ta-Mao-Tao) were selected as the best cold-tolerant varieties. Our results also indicate the benefits of warming treatments to protect rice seedlings from low temperature conditions.
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Bryant, Tim B., Seth J. Dorman, Dominic D. Reisig, DeShae Dillard, Roger Schürch, and Sally V. Taylor. "Reevaluating the Economic Injury Level for Brown Stink Bug (Hemiptera: Pentatomidae) at Various Growth Stages of Maize." Journal of Economic Entomology 113, no. 5 (2020): 2250–58. http://dx.doi.org/10.1093/jee/toaa173.
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Abstract Economic yield loss and reduction in grain quality from brown stink bug, Euschistus servus (Say), feeding injury in early and late stages of maize, Zea mays (Poales: Poaceae, Linnaeus), development was assessed in Virginia and North Carolina in 2018 and 2019. Varying levels of stink bug infestations were introduced to seedling maize (V2—early stage), and a range of late-stages of maize, including 1) the last stage of vegetative development (V12/V14), 2) prior to tasseling, 3) at tasseling (VT), and 4) across all tested late growth stages. Euschistus servus infestation levels included 33, 67, and 100% of maize seedlings, and 25, 50, 100, and 200% of plants during later stages. Infestations were maintained on seedling maize for 7 d, and 8 or 16 d in reproductive stages. Infestation level in seedling maize had an impact on grain yield. Infestation level and growth stage both had an impact on grain yield in reproductive maize. The percentage of discolored kernels was also affected by infestation level, but not growth stage. Regression analysis between grain yield and infestation level indicated that the average economic injury level is 7% in seedling maize (7 bugs/100 plants) and 12% (12 bugs/100 plants) from the last vegetative stages (V12/V14) through pollination (VT). The economic injury level in the late vegetative stages is only applicable when infestations are present for an extended period of time (16 d), emphasizing the need for continued scouting of maize throughout the season to make informed management decisions.
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Bisognin, Dilson Antônio, Luis Velasquez, and Irvin Widders. "Cucumber seedling dependence on cotyledonary leaves for early growth." Pesquisa Agropecuária Brasileira 40, no. 6 (2005): 531–39. http://dx.doi.org/10.1590/s0100-204x2005000600002.
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The objective of this work was to evaluate the dependence of cucumber (Cucumis sativus L.) seedlings on cotyledonary leaves for early growth and establishment. Sets of two uniform emerging seedlings were used to quantify the initial growth and dry matter accumulation, as well as the intensity and stage of cotyledon damage in seedling establishment and to determine cotyledon protein, amino acid and carbohydrate contributions to the growing seedling. Cucumber seedling establishment was found to be highly dependent on cotyledonary leaves. Root system establishment was highly dependent on the health of the aerial part. One cotyledon was enough to maintain aerial growth of seedlings after unfolding the first true leaf. Cucumber seedlings depended on both cotyledons to keep root system growth at least until leaf area was equivalent to cotyledon area. Covering one or both cotyledons of seedlings with one unfolded leaf increased carbohydrate content of uncovered cotyledon and leaves compared with control seedlings. Cucumber seedlings are highly dependent on cotyledonary leaves and aerial parts are less dependent than root system. Cotyledon damage at early stages of plant establishment would adversely impact crop yield by reducing plant density, an important yield component, or slowing down seedling growth and establishment.
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Möhler, Henrike, Tim Diekötter, Geeltje Marie Bauer, and Tobias W. Donath. "Conspecific and heterospecific grass litter effects on seedling emergence and growth in ragwort (Jacobaea vulgaris)." PLOS ONE 16, no. 2 (2021): e0246459. http://dx.doi.org/10.1371/journal.pone.0246459.
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Jacobaea vulgaris Gaertn. or common ragwort is a widespread noxious grassland weed that is subject to different regulation measures worldwide. Seedling emergence and growth are the most crucial stages for most plants during their life cycle. Therefore, heterospecific grass or conspecific ragwort litter as well as soil-mediated effects may be of relevance for ragwort control. Our study examines the effects of conspecific and heterospecific litter as well as ragwort conditioned soil on seedling emergence and growth. We conducted pot experiments to estimate the influence of soil conditioning (with, without ragwort), litter type (grass, ragwort, grass-ragwort-mix) and amount (200 g/m², 400 g/m²) on J. vulgaris recruitment. As response parameters, we assessed seedling number, biomass, height and number of seedling leaves. We found that 200 g/m² grass litter led to higher seedling numbers, while litter composed of J. vulgaris reduced seedling emergence. Litter amounts of 400 g/m² had negative effects on the number of seedlings regardless of the litter type. Results for biomass, plant height and leaf number showed opposing patterns to seedling numbers. Seedlings in pots treated with high litter amounts and seedlings in ragwort litter became heavier, grew higher and had more leaves. Significant effects of the soil conditioned by ragwort on seedling emergence and growth were negligible. The study confirms that the amount and composition of litter strongly affect seedling emergence and growth of J. vulgaris. Moreover, while conspecific litter and high litter amounts negatively affected early seedling development in ragwort, those seedlings that survived accumulated more biomass and got taller than seedlings grown in heterospecific or less dense litter. Therefore, ragwort litter has negative effects in ragwort germination, but positive effects in ragwort growth. Thus, leaving ragwort litter on pastures will not reduce ragwort establishment and growth and cannot be used as management tool.
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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.
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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.
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Zacks, Georgina, Joe Greet, Christopher J. Walsh, and Elisa Raulings. "The flooding tolerance of two critical habitat-forming wetland shrubs, Leptospermum lanigerum and Melaleuca squarrosa, at different life history stages." Australian Journal of Botany 66, no. 7 (2018): 500. http://dx.doi.org/10.1071/bt18039.
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Understanding the effect of water regime on the different life history stages of woody wetland plants is essential to managing their persistence. The common and widespread myrtaceous shrub species, Melaleuca squarrosa Donn. ex Sm. and Leptospermum lanigerum (Aiton) Sm., provide habitat for two critically endangered fauna within the Yellingbo Nature Conservation Reserve (south-eastern Australia), but are in decline putatively because of the altered flooding regimes. We, thus, tested the effects of flooding depth and duration on their seed germination and seedling establishment, and seedling growth and survival in two separate glasshouse experiments. We also compared the condition of mature plants of both species at an intermittently flooded (reference) site, and two near permanently flooded (impact) sites. Seeds of both species were able to germinate underwater, but early flooding reduced seedling establishment. Seedling growth of both species was greater in waterlogged than in well drained or inundated conditions, whereas no seedlings of either species survived >8 weeks of submergence. Leptospermum lanigerum seedlings were generally more flood tolerant than were M. squarrosa seedlings. Correspondingly, crown condition of mature M. squarrosa, but not L. lanigerum, was poorer at impact than reference sites. Prolonged flooding in swamp forests is likely to (1) limit woody plant recruitment, because flooding reduces seedling establishment, growth and survival, and (2) be deleterious to the maintenance of less flood-tolerant species (e.g. M. squarrosa). Moist exposed substrate is likely to be best for promoting the recruitment of both study species, and intermittent flooding for maintaining adult M. squarrosa plants.
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Castro, Jorge, and Alexandro Leverkus. "Effect of Herbaceous Layer Interference on the Post-Fire Regeneration of a Serotinous Pine (Pinus pinaster Aiton) across Two Seedling Ages." Forests 10, no. 1 (2019): 74. http://dx.doi.org/10.3390/f10010074.
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Herbaceous vegetation is a major source of interference with the regeneration of woody species. This is particularly the case after forest fires, as a dense herbaceous layer usually regenerates naturally. Although the competitive effect of the herbaceous vegetation upon tree seedlings has been widely studied, there are still gaps in knowledge for management related to the effect of tree seedling age and size on the outcome of the interaction. In this study, we seek to determine the response of maritime pine (Pinus pinaster Aiton) seedlings to herbaceous competition at two different seedling ages. For that, two treatments of herbaceous competition were implemented, namely unweeded (no action around pine seedlings) and weeded (herbaceous cover removed around pine seedlings). Treatments were conducted twice (2 and 4 years after the fire), and we monitored seedling survival and growth at the end of each growing season. The treatments were implemented across three adjacent landscape units that differed in the management of burned wood and that are representative of common post-fire scenarios: no intervention, salvage logging, and an intermediate degree of intervention. Weeding increased seedling survival from 44.7% to 67.8% when seedlings were 2 years old, but had no effect for four-year-old seedlings, which showed 99% survival. Seedling growth also increased in the weeding treatment, but only slightly. Moreover, growth (and survival for two-year-old seedlings) was strongly correlated with initial seedling size, particularly in the case of two-year-old seedlings. Initial pine seedling height was strongly and positively correlated with the height of the herbaceous layer, supporting the existence of microsite features that promote plant growth above competitive effects. The results support that management actions conducive to foster post-fire pine forest restoration in this Mediterranean ecosystem should reduce herbaceous competition at early stages after fire (second or third year) and focus on larger seedlings.
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Ali, Murad, Zia Ullah, Muhammad Saeed, Ahmad Zubair, Ansaar Ahmed, and Bilal Ahmad. "Impact of Irrigation on Yield Attributes of Seven Wheat Genotypes." Bangladesh Journal of Botany 50, no. 2 (2021): 235–43. http://dx.doi.org/10.3329/bjb.v50i2.54078.
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Seven wheat genotypes i.e., PR-110, PR-112, PR-115, PR-118, PR-119, PR-120 and Pirsabak-13 were evaluated at: I0: Control, I1: irrigation at seedling stage, I2: irrigation at seedling and booting stages, I3: irrigation at seedling, tillering and booting stages and I4: irrigation at seedling, tillering, booting and grain formation stages. Among the genotypes, PR-115, PR-118 and PR-120 were found to be superior for grain yield and its related attributes under full and deficit water conditions. Irrigation at seedling + tillering + booting stages + grain formation stages (I4) produced statistically higher yield and related traits. It was also observed that in case of water shortage, irrigation at seedling and booting stages reduced the drastic losses in grain yield of wheat. The study suggested that identified promising wheat genotypes can be utilized in future breeding programs to develop drought tolerant varieties.
 Bangladesh J. Bot. 50(2): 235-243, 2021 (June)
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Sathya, S., S. Lakshmi, and S. Nakkeeran. "Combined effect of biopriming and polymer coating on chemical constituents of root exudation in chilli (Capsicum annuum L.) cv. K 2 seedlings." Journal of Applied and Natural Science 8, no. 4 (2016): 2141–54. http://dx.doi.org/10.31018/jans.v8i4.1104.
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A study was carried out to analyze the different volatile compounds in bioprimed chilli (Capsicum annuum L.) seedlings of 15 and 30 day old. A common compound found in two stages of chilli seedlings was hydroxylamine, dimethoxydimethyl silane, hexadecanoic acid, 15-methyl- methyl ester. Majority of the compounds in bacterized seedlings had antimicrobial activity. The results on GCMS analysis revealed that, root exudates collected from 15 and 30 days old bacterized seedlings with B. amyloliquefaciens VB7 and polymer coating released more number of volatile compounds (65 and 20 compounds respectively) than control (5 and 15 compounds respectively). The root exudates of 15 day old seedling released more volatile compounds (65 nos) than 30 days (20 nos) old seedling.
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Bessa, Layara Alexandre, Luciana Cristina Vitorino, and Fabiano Guimarães Silva. "Micronutrient deficiency affects the development of the seedlings of the cagaita, a Myrtaceae typical of the Brazilian Cerrado." Research, Society and Development 9, no. 11 (2020): e65391110209. http://dx.doi.org/10.33448/rsd-v9i11.10209.
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Cagaita (Eugenia dysenterica DC.) plants are highly dependent on the micronutrient iron during their early development stages. Given this, we tested the hypothesis that initial seedling development is affected by a lack of specific micronutrients. We planted seedlings of this species in standard hydroponic solution, and in individual treatments, in which B, Cu, Fe, Mn, Zn or Mo were omitted. The development of symptoms of micronutrient deficiency in response to the different treatment solutions was monitored visually for 120 days after transplantation, and growth parameters and the content of different nutrients in the plant tissue were determined. The deficiency of the micronutrient Mo was the treatment with the greatest effect on seedling growth. The most commonly observed symptoms of nutrient deficiency were chlorosis and necrosis (Cu and Zn deprivation) and impaired root hair development (Fe and Cu deprivation). Overall, Fe was the micronutrient that accumulated most in the stems and roots of the seedlings exposed to the standard nutrient solution, which confirms the importance of the availability of this nutrient in the initial stages of seedling development for the production of healthy cagaita plants, with greater viability.
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Song, Yong Xian, Juan Li Ma, and Xian Jin Zhang. "Design of Water and Fertilizer Measurement and Control System for Seedlings Soil Based on Wireless Sensor Networks." Applied Mechanics and Materials 241-244 (December 2012): 86–91. http://dx.doi.org/10.4028/www.scientific.net/amm.241-244.86.
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Water and fertilizer are two important factors in seedlings growth and development, the reasonable management of water and fertilizer can play a greater growth potential for seedling, and blind management of water and Fertilizer not only is harmful for seedling growth, but also will lead to the water resource waste and environmental pollution. In order to precisely determine the seedlings fertilizer demand, this paper presents a method seedlings fertilizer and water measurement and control system based on wireless sensor network, the system can realize automatic deployment of information acquisition node, data self-organization transfer, namely, wireless communication, and can accurately detect information of soil water and fertilizer and identify water and Fertilizer on the best demand of seedlings growth stages for different seedlings, different regions, different period of climate and seedling growth status, so the best water and fertilizer control is achieved in seedling cultivation. This system were introduced and analyzed from the hardware structure, software structure and so on in this paper, and it has the advantages of low power consumption, low cost, good robustness, flexibility and so on. The experiment results shown that the system is practical and efficient, which can be applied in farmland, and nursery area.
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Vytisková, Marie, Radim Cerkal, and Ivan Malý. "Influence of seedlings quality on consumer parts of selected species of cabbages." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 54, no. 2 (2006): 147–58. http://dx.doi.org/10.11118/actaun200654020147.
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The aim of this work was to evaluate the influence of seedling preparation technology (seedling flats with cell size of 20 ml, 40 ml and seedlings pulled from patches) and of seedling age at the time of planting (development stages of 3–4 true leaves and 5–6 true leaves) to the qualitative characteristics of seedling of selected cabbage species: white cabbage (Brassica oleraceaL. convar.capitata(L.) Alef. var.albaDC.) –Aros, Avak,Midor; cauliflower (Brassica oleraceaL. convar.botrytis(L.) Alef. var.botrytisL.) –Beta, Delta, Roberand savoy cabbage (Brassica oleraceaL. convar.capitata(L.) Alef. var.sabaudaL.) –Vega, Versus. The diameter and weight of rosaces, resp. heads, was evaluated in the harvested production. After splitting the harvested crop into several groups, the percentage of non-standard portion of the yield was determined. The use of older seedlings (5–6 true leaves) for the white and savoy cabbage planting had a positive influence to both average yield and the harvest earliness. On the other hand, for the cauliflower conclusively better average crop of rosaces and earlier harvests were achieved with younger seedling transplanting (3–4 true leaves). Seedling flats proved to be the most suitable way of seedling preplantation; no differences were found between the characteristics of products cultivated from the seedling flats with 20 ml and 40 ml cell volumes. In average, smaller amount of non-standard harvest plant parts was, gained with the transplanting from larger seedling flats (40 ml cell volume).
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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.
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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.
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Cuyckens, Griet An Erica, Flavia Mazzini, Rocío F. Julián, David E. Medina, and Gustavo F. Guzmán. "Effect of livestock on regeneration of queñoa (Polylepis australis Bitt.) forest in the Southern Andean Yungas of northwestern Argentina." Revista Chapingo Serie Ciencias Forestales y del Ambiente 27, no. 2 (2020): 215–28. http://dx.doi.org/10.5154/r.rchscfa.2020.05.035.
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Introduction: Polylepis forest is an ecosystem stated with conservation priority and threatened by anthropogenic effects; extensive livestock is one of the most frequent disturbances. Objective: To study the effect of livestock on the early stages of regeneration of a queñoa (Polylepis australis Bitt.) forest. Materials and methods: Within a pure forest of P. australis at Parque Provincial Potrero de Yala, Jujuy, Argentina, densities of seedlings (˂1 year) and saplings (˃1 year and ˂30 cm) were measured in the presence (0.23 heads∙ha-1) and absence of livestock, for a year. Linear mixed models(normal distribution) were adjusted for density of seedlings and saplings. Data was analyzed with a Chi-square test (X2). Results and discussion: Presence of livestock had no impact on seedling density, but significantly decreased density of saplings (P < 0.001); in areas without livestock (10.58 ± 6.64 individuals∙m-2) was three times higher than with presence of livestock (3.17 ± 3.86 individuals∙m-2). Difference in density of seedlings and saplings was significantly (P < 0.001) over time. This indicates that there is potential for natural regeneration, but livestock would affect stages after seedling emergence, representing a threat to the forest. Conclusion: This study provides important information on livestock management in mountain forests of P. australis. A long-term study of the effect of livestock on seedling and sapling density, and over the entire distribution range, is needed.
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Wisudayati, Tri Astuti, Dian Charity Hidayat, and Dede J. Sudrajat. "The Development of Non-Tax State Revenue Potency by Applying the Logical Framework Approach: A Case Study of Nagrak Research Station in Bogor District, West Java." Jurnal Penelitian Kehutanan Wallacea 8, no. 2 (2019): 93. http://dx.doi.org/10.18330/jwallacea.2019.vol8iss2pp93-103.
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The Indonesian government strives to increase non-tax state revenues (PNBP). One of the potentials PNBP is using the state assets, such as research stations, for the public interest. This paper was aimed to formulate a strategy for the PNBP potential development using the Logical Framework Approach (LFA), with a case study at the Nagrak Research Station, Bogor. In order to avoid the failure when the PNBP potential development’s stages are implemented, policy makers need to build a hierarchy based on logical thinking of input, activity, output, impact, objectives and summarized them in a work plans matrix. The process of LFA development starts with the analysis of problems, goals, and strategies. Data and information were obtained through participant observation and documentation studies. The results showed that the commercialization of the operational units of research quality’ s seeds and seedlings at the Nagrak Research Station must be supported by the government policy, including: (1) planning of seed and seedling production with the consideration of price competitiveness (2) seeds and seedling production with the financial management flexibilities, and (3) seeds and seedling distribution with stakeholders protection from the non-quality seeds and seedling’s utilization.
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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.
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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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Li, Jia-Rui, J. T. A. Proctor, and D. P. Murr. "Effects of cotyledon removal on apple seedling growth and distribution of 14C-labelled photosynthates." Canadian Journal of Botany 63, no. 10 (1985): 1736–39. http://dx.doi.org/10.1139/b85-243.
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In very young apple (Malus domestica Borkh.) seedlings, cotyledon dry weight decreased during the 14-day period following cotyledon separation and development. Removal of both cotyledons at the time of cotyledon separation significantly reduced subsequent seedling development as measured by leaf area and leaf fresh and dry weights, but it did not alter established 14C-labelled photosynthate transport patterns. Cotyledon removal from seedlings with fully expanded cotyledons and four unfolded expanding true leaves did not affect subsequent seedling growth. Removal of one cotyledon in very young seedlings reduced retention and export and increased apparent metabolism of 14C-labelled photosynthate. Removal of one cotyledon in older seedlings to which 14CO2 was fed to the first true leaf did not influence retention, export, or metabolism of the 14C-labelled photosynthate in the fed leaf. In the early stages of seedling growth, assimilates were directed mainly to the lower stem and root system, then to the shoot apex and immature leaves, and finally again to the root system as the first true leaf assumed the function of supplying assimilates during cotyledonary senescence.
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Almeida, Hisaias de Souza, Anne Priscila Dias Gonzaga, Helaine de Sousa, Yule Roberta Ferreira Nunes, and Henrique Nery Cipriani. "Cotyledon integrity on Anadenanthera colubrina (vell.) brenan (fabaceae - mimosoideae) germination and early establishment." CERNE 16, no. 2 (2010): 227–64. http://dx.doi.org/10.1590/s0104-77602010000200015.
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Despite the major ecological and economical relevance of forest species, little is known about their seedling establishment and seed germination, as well as the damage effects to seeds at these stages. This work aimed to assess the effects of partial cotyledon loss on the seed germination and early seedling establishment of Anadenanthera colubrina. Therefore, whole (control) and split seeds (with ¹/8, ¹/4, and ½ of their size cut) were evaluated. The seeds were then germinated and the early growth of seedlings was assessed. The treatments had no effect on seed germination, however, they influenced seedling survival and establishment. The highest mortality and growth reduction values were obtained with the most severe cotyledon removal. This indicates that the tegument and the partial cotyledon loss do not represent a barrier against seed germination. However, considerable damages may be detrimental to establishment and survival of A. colubrina seedlings.
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Krishnan, Lalitha, Deepak Barua, and Mahesh Sankaran. "Dry-forest tree species with large seeds and low stem specific density show greater survival under drought." Journal of Tropical Ecology 35, no. 1 (2019): 26–33. http://dx.doi.org/10.1017/s0266467418000421.
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AbstractTree establishment in tropical dry forests is constrained by drought-related seedling mortality during early stages of recruitment. Predicted increases in the duration of growing-season droughts in the future pose a significant threat to these ecosystems that could significantly alter their vegetation structure and composition. Here, we examined drought tolerance in seedlings of seven common dry-forest tree species from the Indian subcontinent. We conducted a dry-down experiment on 3-wk-old seedlings, and asked whether the key plant functional traits, specific leaf area (SLA), leaf dry matter content (LDMC), seed size and stem specific density (SSD) were good predictors of seedling growth under well-watered conditions, and survival during drought. Seedlings displayed substantial drought tolerance with most seedlings surviving for more than 2 wk under protracted drought. Seed size in combination with SLA predicted seedling growth under well-watered conditions and seed size predicted survival under drought. In contrast to our expectations, seedlings with lower SSD survived for longer without water. Our results suggest that dry-forest species will be differentially affected by the predicted increases in the duration of growing-season droughts, and detrimental effects will be more severe for species with smaller seeds.
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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.
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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.
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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.
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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.
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Li, Jingang, Jing Chen, Zhongyi Qu, Shaoli Wang, Pingru He, and Na Zhang. "Effects of Alternating Irrigation with Fresh and Saline Water on the Soil Salt, Soil Nutrients, and Yield of Tomatoes." Water 11, no. 8 (2019): 1693. http://dx.doi.org/10.3390/w11081693.
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Saline water irrigation has become extremely important in arid and semi-arid areas in northwestern China. To study the effect of alternating irrigation models on the soil nutrients, soil salts, and yield of tomatoes with fresh water (total dissolved solids of 0.50 g·L−1) and saline water (total dissolved solids of 3.01 g·L−1), a two-year field experiment was carried out for tomatoes in the Hetao Irrigation District (HID), containing six drip irrigation models: T1 (all freshwater irrigation), T2 (saline water used in the seedling and flowering stages; fresh water in the fruit-set and breaker stages), T3 (saline water in the flowering and fruit-set stages; fresh water in the seedling and breaker stages), T4 (saline water in the fruit-set and breaker stages; fresh water in the seedling and flowering stages), T5 (saline water in the flowering and breaker stages; fresh water in the seedling and fruit-set stages), T6 (saline water in the seedling and fruit-set stages; fresh water in the flowering and breaker stages). The study found that saline water irrigation tends to have a positive effect on soil total nitrogen and a negative influence on soil total phosphorus at each growth stage of the tomato. Soil Na+, Mg2+, Ca2+, K+, and Cl− increased over the growth period, soil HCO3− decreased gradually by growth stage, and the salt ions increased with the amount of saline water applied in alternating irrigation. Though the soil salt accumulated in all experimentally designed alternating irrigation models, soil alkalization did not occur in the tomato root zone under the soil matric potential threshold of −25 kPa. The utilization of saline water resulted in about a 1.9–18.2% decline in fruit yield, but the total soluble solids, lycopene, and sugar in the tomato fruits increased. Ultimately, drip irrigation with fresh water at the seedling to flowering stages and saline water at the fruit-set to breaker stages was suggested for tomato cultivation in HID.
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FISCH, Simey Thury Vieira, Isolde Dorothea Kossmann FERRAZ, and William Antonio RODRIGUES. "DISTINGUISHING Campa guianensis Aubl. FROM Campa procera D.C. (MELIACEAE) BY MORPHOLOGY OF YOUNG SEEDLINGS." Acta Amazonica 25, no. 3-4 (1995): 193–200. http://dx.doi.org/10.1590/1809-43921995253200.
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Seedling morphology was studied in Campa guianensisAubl. and Carapa proceraD. C. from germination to 90 days age. In both species germination is hypogeal and cryptocotylar. Both have rare albino seedlings. Though both species have compound leaves when adult, C, proceraputs out an average total of six simple leaves at germination, while leaves of C. guianensisare compound at all stages. This is the best diagnostic character for separation of the two species at the young seedling stage. Not diagnostic, but none the less useful, is the fact, that polyembryonic seeds are often found in C. procera,but not observed in C guianensis.
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Johnson, Daniel J., Richard Condit, Stephen P. Hubbell, and Liza S. Comita. "Abiotic niche partitioning and negative density dependence drive tree seedling survival in a tropical forest." Proceedings of the Royal Society B: Biological Sciences 284, no. 1869 (2017): 20172210. http://dx.doi.org/10.1098/rspb.2017.2210.
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In tropical tree communities, processes occurring during early life stages play a critical role in shaping forest composition and diversity through differences in species' performance. Predicting the future of tropical forests depends on a solid understanding of the drivers of seedling survival. At the same time, factors determining spatial and temporal patterns of seedling survival can play a large role in permitting species coexistence in diverse communities. Using long-term data on the survival of more than 45 000 seedlings of 238 species in a Neotropical forest, we assessed the relative importance of key abiotic and biotic neighbourhood variables thought to influence individual seedling survival and tested whether species vary significantly in their responses to these variables, consistent with niche differences. At the community level, seedling survival was significantly correlated with plant size, topographic habitat, neighbourhood densities of conspecific seedlings, conspecific and heterospecific trees and annual variation in water availability, in descending order of effect size. Additionally, we found significant variation among species in their sensitivity to light and water availability, as well as in their survival within different topographic habitats, indicating the potential for niche differentiation among species that could allow for species coexistence.
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Sane, Noor Us, Dhiman Bhusan, Papon Kumar Deb Nath, Yoshiyuki Murata, and Md Anamul Hoque. "Improving salinity tolerance in transplanted aman rice (Oryza sativa L.) by exogenous application of proline." Journal of the Bangladesh Agricultural University 17, no. 2 (2019): 194–99. http://dx.doi.org/10.3329/jbau.v17i2.41943.
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Salinity is the major factor reducing crop yield in coastal areas of Bangladesh. Proline (Pro) application with suitable crop varieties having higher yield potential could contribute to the improvement of crop production in saline areas. The main objective of this study was to investigate the mitigation of adverse effects of salinity in aman rice by exogenously applied Pro. The experiment was carried out at the farmer’s field of Batiaghata, Khulna. Characteristically, the soil was silty clay loam having pH 6.7, EC 4.6 dS m–1, CEC 23 meq/100 g soil, organic matter 0.71%. Rice (Oryza sativa L.) variety BR23 was used as plant material. The experiment was laid out in a randomized complete block design with three replications. There were different treatment combinations namely control (no Pro), 25 mM Pro at seedling stage, 25 mM Pro at vegetative stage, 25 mM Pro at seedling and vegetative stages, 50 mM Pro at seedling stage, 50 mM Pro at vegetative stage, 50 mM Pro at seedling and vegetative stages, 100 mM Pro at seedling stage, 100 mM Pro at vegetative stages, and 100 mM Pro at seedling and vegetative stages. Recommended doses of N, P, K, S and Zn fertilizers were applied to the all experimental plots. Thirty-day-old seedlings were transplanted in the experimental plots. Proline solutions were sprayed over plant leaves with the help of sprayer as per treatments. Salinity caused significant reductions in growth and yield of BR23 by decreasing plant height, number of effective tillers, panicle length, filled grains panicle-1 and 1000-grain weight. On the other hand, exogenous application of Pro showed a significant increase in growth and yield of BR23 under saline conditions. Results also revealed that growth and yield of rice did not increase proportionally with the increasing doses of Pro. Proline application resulted in significant increases in K+/Na+ and nutrient uptake by rice under salinity. The present study suggests that exogenous application of Pro confers tolerance to salinity in aman rice by increasing K+/Na+ ratio and nutrient uptake.
 J. Bangladesh Agril. Univ. 17(2): 194–199, June 2019
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Rosales-Robles, Enrique, James M. Chandler, Scott A. Senseman, and Eric P. Prostko. "Influence of Growth Stage and Herbicide Rate on Postemergence Johnsongrass (Sorghum halepense) Control." Weed Technology 13, no. 3 (1999): 525–29. http://dx.doi.org/10.1017/s0890037x00046145.
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Studies were conducted to observe the effect of full and reduced rates of postemergence (POST) herbicides on seedling and rhizome johnsongrass (Sorghum halepense) at different growth stages. Herbicides and labeled rates included primisulfuron at 40 g/ha, nicosulfuron at 35 g/ha, fluazifop-P at 210 g/ha, and clethodim at 140 g/ha. Contour graphs to predict johnsongrass control at different growth stages and herbicide rates were developed. Excellent seedling and rhizome johnsongrass control was obtained with reduced rates of herbicides applied at the three- to five-leaf stages. Primisulfuron at 20 g/ha resulted in 90% or greater control of seedling johnsongrass in the three- to four-leaf stage. Rhizome johnsongrass at this growth stage required 30 g/ha of primisulfuron for the same level of control. Nicosulfuron at 17.5 and 26.3 g/ha provided 90% or greater control up to the four-leaf stage of seedling and rhizome johnsongrass, respectively. Fluazifop-P and clethodim were more effective than primisulfuron and nicosulfuron. Fluazifop-P at 105 g/ha resulted in 90% or greater control of seedling and rhizome johnsongrass up to the seven- and five-leaf stages, respectively. Clethodim at 35 g/ha controlled seedling johnsongrass at least 90% up to the eight-leaf stage. Clethodim at 70 g/ha provided 90% or greater control of rhizome johnsongrass if applied at the three- to four-leaf stages.
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Xiao, Zhang, Yu Tan, Xingxing Liu, and Shenghui Yang. "Classification Method of Plug Seedlings Based on Transfer Learning." Applied Sciences 9, no. 13 (2019): 2725. http://dx.doi.org/10.3390/app9132725.
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The classification of plug seedlings is important work in the replanting process. This paper proposed a classification method for plug seedlings based on transfer learning. Firstly, by extracting and graying the interest region of the original image acquired, a regional grayscale cumulative distribution curve is obtained. Calculating the number of peak points of the curve to identify the plug tray specification is then done. Secondly, the transfer learning method based on convolutional neural network is used to construct the classification model of plug seedlings. According to the growth characteristics of the seedlings, 2286 seedlings samples were collected to train the model at the two-leaf and one-heart stages. Finally, the image of the interest region is divided into cell images according to the specification of the plug tray, and the cell images are put into the classification model, thereby classifying the qualified seedling, the unqualified seedling and the lack of seedling. After testing, the identification method of the tray specification has an average accuracy of 100% for the three specifications (50 cells, 72 cells, 105 cells) of the 20-day and 25-day pepper seedlings. Seedling classification models based on the transfer learning method of four different convolutional neural networks (Alexnet, Inception-v3, Resnet-18, VGG16) are constructed and tested. The classification accuracy of the VGG16-based classification model is the best, which is 95.50%, the Alexnet-based classification model has the shortest training time, which is 6 min and 8 s. This research has certain theoretical reference significance for intelligent replanting classification work.
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Mwando, Edward, Tefera Tolera Angessa, Yong Han, Gaofeng Zhou, and Chengdao Li. "Quantitative Trait Loci Mapping for Vigour and Survival Traits of Barley Seedlings after Germinating under Salinity Stress." Agronomy 11, no. 1 (2021): 103. http://dx.doi.org/10.3390/agronomy11010103.
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Seed germination and seedling establishment are the most critical stages in the barley (Hordeum vulgare ssp. vulgare L.) life cycle that contribute substantially to grain yield. These two phases are exposed to several forms of environmental stresses such as salinity due to high level of salt accumulation in the soil rhizosphere where seed germination takes place and seedlings emerge from. Previously, we have reported genotypic variability and independent QTLs associated with salinity tolerance at seedling and germination stages. However, genotypic studies on revival of a seedling germinating under salinity stress are yet to close the lack of information between germination and seedling stages. Here, we attempt to close the genetic gap by targeting early seedling survival traits in barley after germination under salinity (NaCl) stress and the various seedling vigour indices. Seedling vigour parameters formed the basis for Quantitative trait locus (QTL) linkage mapping in 103 Doubled Haploid (DH) lines of CM72/Gairdner population, and validated the phenotypic response using a selected diverse panel of 85 barley germplasm. The results indicate that 150 mM NaCl stress significantly reduced all the recorded phenotypic traits compared to 75, 90 and 120 mM NaCl. In both DH population and diversity panel barley germplasm, the highest percentage reduction was recorded in shoot length (65.6% and 50.3%) followed by seedling vigour index length (56.5% and 41.0%), while root length (28.6% and 15.8%) and root dry weight (29.3% and 28.0%) were least reduced when control was compared to150 mM NaCl stress treatment. Six QTLs containing 13 significant markers were detected in the DH population, 3 on chromosomes 1H, 8 on 3H and 2 on 4H with LOD values ranging from 3 to 8 associated with seedling survival traits under salinity stress. Three QTLs one on 1H and two on 3H with closely linked significant markers (Bmac0032, bPb-9418 and bPb-4741), (bPb-4576 and bPb-9624) and (bPb-3623, bPb-5666 and bPb-6383) for 1H and two on 3H respectively formed the regions with high possibility of candidate genes. A QTL on 3H flanked with markers bPb-4576 and bPb-9624 that were detected in more than one salinity survival trait and were closely linked to each other will form a basis for detailed studies leading to gene functional analysis, genetic transformation and marker assisted selection (MAS).
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Mwando, Edward, Tefera Tolera Angessa, Yong Han, Gaofeng Zhou, and Chengdao Li. "Quantitative Trait Loci Mapping for Vigour and Survival Traits of Barley Seedlings after Germinating under Salinity Stress." Agronomy 11, no. 1 (2021): 103. http://dx.doi.org/10.3390/agronomy11010103.
Full textAbstract:
Seed germination and seedling establishment are the most critical stages in the barley (Hordeum vulgare ssp. vulgare L.) life cycle that contribute substantially to grain yield. These two phases are exposed to several forms of environmental stresses such as salinity due to high level of salt accumulation in the soil rhizosphere where seed germination takes place and seedlings emerge from. Previously, we have reported genotypic variability and independent QTLs associated with salinity tolerance at seedling and germination stages. However, genotypic studies on revival of a seedling germinating under salinity stress are yet to close the lack of information between germination and seedling stages. Here, we attempt to close the genetic gap by targeting early seedling survival traits in barley after germination under salinity (NaCl) stress and the various seedling vigour indices. Seedling vigour parameters formed the basis for Quantitative trait locus (QTL) linkage mapping in 103 Doubled Haploid (DH) lines of CM72/Gairdner population, and validated the phenotypic response using a selected diverse panel of 85 barley germplasm. The results indicate that 150 mM NaCl stress significantly reduced all the recorded phenotypic traits compared to 75, 90 and 120 mM NaCl. In both DH population and diversity panel barley germplasm, the highest percentage reduction was recorded in shoot length (65.6% and 50.3%) followed by seedling vigour index length (56.5% and 41.0%), while root length (28.6% and 15.8%) and root dry weight (29.3% and 28.0%) were least reduced when control was compared to150 mM NaCl stress treatment. Six QTLs containing 13 significant markers were detected in the DH population, 3 on chromosomes 1H, 8 on 3H and 2 on 4H with LOD values ranging from 3 to 8 associated with seedling survival traits under salinity stress. Three QTLs one on 1H and two on 3H with closely linked significant markers (Bmac0032, bPb-9418 and bPb-4741), (bPb-4576 and bPb-9624) and (bPb-3623, bPb-5666 and bPb-6383) for 1H and two on 3H respectively formed the regions with high possibility of candidate genes. A QTL on 3H flanked with markers bPb-4576 and bPb-9624 that were detected in more than one salinity survival trait and were closely linked to each other will form a basis for detailed studies leading to gene functional analysis, genetic transformation and marker assisted selection (MAS).
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Diniz, Fábio Oliveira, Múcio Silva Reis, Eduardo Fontes Araújo, Luiz Antônio dos Santos Dias, Tuneo Sediyama, and Camilla Atsumi Zanuncio Sediyama-Bhering. "Incidence of pathogens and field emergence of soybean seeds subjected to harvest delay." Journal of Seed Science 35, no. 4 (2013): 478–84. http://dx.doi.org/10.1590/s2317-15372013000400009.
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This study aimed at evaluating seed health quality, as well as seedling emergence in the field, of eight soybean cultivars (UFV-16, Splendor, Vencedora, Confiança, UFV-18, UFV-TN 105, Garantia, and Celeste) subjected to different harvest periods. To this, seeds were harvested at the growth stages R8, R8+15 days, and R8+30 days, and then submitted to health test and to the test of seedling emergence in field. Results showed that although seeds harvested at 15 and 30 days after the stage R8 had shown a significant increase of fungi infection, especially by Fusarium spp., Phomopsis spp., and Epicoccum spp., the percent seedling emergence in the field was reduced only to seeds harvested 30 days after the reproductive stage R8. Cultivars have shown differentiated behavior between each other in relation to the percent incidence rate of fungi and seedling emergence in the field; and the seeds least infected by fungi were those allowing the highest percent emergence of seedlings in the field.
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Ramsay, Carol A., and Garrell E. Long. "SURVIVAL OF LARCH CASEBEARERS, COLEOPHORA LARICELLA (HUBNER), ON FOLIAGE OF EIGHT SEEDLING CONIFERS." Canadian Entomologist 120, no. 11 (1988): 993–96. http://dx.doi.org/10.4039/ent120993-11.
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AbstractA no-choice feeding study was used to evaluate larch casebearer development and survival on eight species of conifer seedlings and two foliar stages of larch from molting to the fourth-instar larvae through adult eclosion. Percentage survival through adult eclosion varied on foliage of western larch (spring—flush stage, 44%; fall—bud set stage, 23%), Douglas-fir (40%), grand fir (26%), Englemann spruce (26%), western white pine (10%), and lodgepole pine (6%). No survival occurred on ponderosa pine or western hemlock. The rate of development differed among conifer seedling species, and between foliar stages of larch.
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Urbieta, Itziar R., Ignacio M. Pérez-Ramos, Miguel A. Zavala, Teodoro Marañón, and Richard K. Kobe. "Soil water content and emergence time control seedling establishment in three co-occurring Mediterranean oak species." Canadian Journal of Forest Research 38, no. 9 (2008): 2382–93. http://dx.doi.org/10.1139/x08-089.
Full textAbstract:
Tree species can differ in their responses to resource availability during the critical phase of establishment, which could influence forest dynamics. In Mediterranean forests, most of the attention has focused on the effects of shade and summer drought on seedling survival, but little is known about the effect of autumn to spring rains on earlier stages of recruitment. A sowing experiment was set up along natural light and water gradients with three co-occurring oak species ( Quercus suber L. (cork oak), Quercus canariensis Willd. (Algerian oak), and Quercus pyrenaica Willd. (Pyrenean oak)) that show limited natural regeneration in southern Spain. Recruitment stages were monitored for 1 year. Models of seed germination, seedling emergence, and seedling survival as well as of overall recruitment patterns were developed as functions of light, soil moisture, and soil compaction. The influence of intraspecific variation in seed mass and emergence time were also tested. Excess soil water levels during the winter reduced germination and emergence and lengthened time to emergence (in waterlogged open areas), which in turn decreased seedling survival during the dry season. Seedlings from larger seeds were more likely to germinate and emerge. The results suggest that temporal and spatial variability of soil water content, mediated by emergence time and seed size, play a crucial role in the regeneration dynamics of Mediterranean oak forests.
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Herrera-Foessel, S. A., R. P. Singh, C. X. Lan, et al. "Yr60, a Gene Conferring Moderate Resistance to Stripe Rust in Wheat." Plant Disease 99, no. 4 (2015): 508–11. http://dx.doi.org/10.1094/pdis-08-14-0796-re.
Full textAbstract:
Stripe rust, caused by Puccinia striiformis f. sp. tritici W., is a devastating disease of wheat worldwide. A new stripe rust resistance gene with moderate seedling and adult plant resistance was mapped using an F5 recombinant inbred line (RIL) population developed from the cross of the resistant parent ‘Almop’ with the susceptible parent ‘Avocet’. The parents and RILs were phenotyped for seedling stripe rust response variation in a greenhouse and in field trials at Toluca, Mexico for 2 years. Almop showed moderate levels of resistance at both seedling and adult plant stages compared with the highly susceptible response of Avocet. The distribution of homozygous resistant, homozygous susceptible, and segregating RILs conformed to segregation at a single locus. Seedlings and adult plant responses were correlated, indicating that the same gene conferred resistance at both stages. A bulk segregant analysis approach with widely distributed simple sequence repeat (SSR) markers mapped the resistance gene to the distal region of the long arm of chromosome 4A. The SSR marker wmc776 cosegregated with this gene, whereas markers wmc219 and wmc313 were tightly linked and both located at 0.6 centimorgans. The resistance locus was designated Yr60.
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Löf, M., and N. T. Welander. "Carry-over effects on growth and transpiration in Fagus sylvatica seedlings after drought at various stages of development." Canadian Journal of Forest Research 30, no. 3 (2000): 468–75. http://dx.doi.org/10.1139/x99-232.
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In the two experiments carried out, newly emerged F. sylvatica seedlings were grown in pots with sand for 2 years in a controlled environmental chamber. Seedling dry mass, leaf area, and number of leaves decreased because of drought in the previous and in the current year. The decrease in area per leaf was due only to the current-year drought. Drought in both the previous and the current year reduced the number of shoots in the current year. Shoot length was mainly affected by previous-year drought. Current-year seedling transpiration decreased because of drought both in the previous and in the current year. The transpiration rate per unit leaf area was not affected by previous-year drought, whereas an after-effect was found within the growing season. The recovery of transpiration following a drought was up to 20 days. Water-use efficiency was influenced by drought during shoot development. The correlation between integrated transpiration and dry mass increase was high. This study shows that both previous as well as current environmental conditions must be taken into consideration when explaining seedling growth.
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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.
Full textAbstract:
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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Santos, Maurício Reginaldo Alves dos, Renato Abreu Lima, Maria das Graças Rodrigues Ferreira, Josilene Felix Rocha, Marcelo Curitiba Espíndola, and Enrique Anastácio Alves. "Acclimatization of micropropagated plantlets of Coffea canephora." Journal of Biotechnology and Biodiversity 5, no. 1 (2014): 12–19. http://dx.doi.org/10.20873/jbb.uft.cemaf.v5n1.santos.
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Coffea canephora is the predominant species in the state of Rondônia, due to its adaptation to soil and climatic conditions in the region. The acclimatization comprises a set of techniques and procedures that are designed to adapt plantlets to field conditions, heterotrophic to autotrophic condition. This work aimed to evaluate conditions of acclimatization of plantlets of C. canephora in relation to the initial stages of seedling development, levels of shading and acclimatization period. In the first experiment, we used three stages of micropropagated plants: "torpedoes", "sprouted" and "seedling" and two levels of shading, 30 and 50% in 3 x 2 factorial. The plants were weighed and placed individually in cells containing the trays Plantmax®. After 30 days, there was survival, plant length, leaf number and fresh weight. The second experiment evaluated three periods of acclimatization at 30, 45 and 60 days, after the seedlings were transferred to field conditions in plastic bags. After 90 days of the deployment of the experiment, there was survival, plant length, leaf number and the ratio between initial and final weight of the seedlings. The developmental stage "seedlings" resulted in increased survival and plant development stages in relation to "torpedo" and "sprouted." The shading of 50% resulted in increased survival and plant growth than 30%. The acclimatization period of 30 days did not differ significantly from the periods of 45 and 60 days, the most suited for this application.
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Campagna, Michel A., and Hank A. Margolis. "Influence of short-term atmospheric CO2 enrichment on growth, allocation patterns, and biochemistry of black spruce seedlings at different stages of development." Canadian Journal of Forest Research 19, no. 6 (1989): 773–82. http://dx.doi.org/10.1139/x89-118.
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Black spruce seedlings (Piceamariana Mill.) were exposed to either elevated (1000 ppm) or ambient (340 ppm) atmospheric CO2 levels at different stages of seedling development over a winter greenhouse production cycle. Seedlings germinated in early February and were placed in CO2 chambers for either 3 or 6 weeks during March, April, May, or August. Total seedling biomass increased under high CO2 conditions for the March, April, and May stages of development, but showed no significant response in August. The greater part of the CO2 response occurred during the second 3 weeks of exposure in March and April but during the first 3 weeks of exposure in May. In September, those seedlings exposed to CO2 in April and May had 30 and 14%, respectively, greater biomass than control seedlings, but seedlings from the other stages of development no longer had significant differences remaining from the CO2 treatment. This suggests that it could be very efficient to give a short well-timed CO2 pulse at the beginning of the production cycle in hopes of producing a size difference that is maintained throughout the remainder of the greenhouse production cycle under ambient levels of CO2. Short-term exposure to elevated CO2 also increased the ratio of shoot dry weight to total height for the March, April, and May stages of development. The ratio of total nonstructural carbohydrates to free amino acids was negatively correlated (r2 = 0.98) with the allocation of new growth between shoots and roots as measured by the allocation coefficient, k (milligrams shoot growth per milligrams root growth). As seedlings developed along their seasonal growth cycle, ratios of total nonstructural carbohydrates to free amino acids increased and the values for k decreased. The effect of CO2 enrichment on these two factors is discussed. Monitoring total nonstructural carbohydrate and free amino acid concentrations in foliage could have potential as a method to predict the percentage of carbon allocated to root systems of entire forest stands as well as of individual tree seedlings.
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Guimarães, Gabriel Castanheira, Sttela Dellyzette Veiga Franco da Rosa, Luis Filipe Serafim Coelho, Adriano Delly Veiga, and Aline da Consolação Sampaio Clemente. "Minimum period to assess the potential of germination of coffee seeds." Journal of Seed Science 35, no. 3 (2013): 347–52. http://dx.doi.org/10.1590/s2317-15372013000300011.
Full textAbstract:
In recent research, early stages of coffee seedling development were identified, after radicle protrusion, in which all the essential parts of the seedling can be assessed to demonstrate the potential of seed germination to generate normal plants. Thus, the objective of this research was to develop studies to reduce the time on the germination test. Ten seed lots of coffee were assessed through the germination test, every two days, from the tenth day of sowing, according to the morphological criteria of the seedlings. The data were compared to the standard germination test and analyzed by means of regression analysis and segmented nonlinear regression and planteau response model. It was concluded that the assessment of coffee seedlings at 16 days, in stage S1, provides the similar result of the pattern germination test, allowing a significant reduction of time in order to demonstrate the germination of the seed lots; the seedling assessment coffee in stage S2 does not have reduction of the time for assessing the coffee germination, in relation to the pattern.