Seed size and dormancy in Rumex obtusifolius

We tested the hypothesis, suggested by literature data, that in Rumex obtusifolius L. the germination of matured seeds harvested from dry standing shoots and achene morphology are correlated. In these seed materials the level of germination is determined by the incidence of primary seed dormancy. The regression of the percentage of germinating seeds on achene, perianth and seed size and mass were calculated for seed materials of 30 plants. The materials in which achene morphology was investigated were selected ex post from a set of seed materials of 241 plants to cover the range of variation of germinability of individual plants which was between 0-66%. There was no relationship between any characteristic of achene quality and germination except for a positive correlation between germination percentage and achene mass calculated only for seed materials of plants which pro duced germinable seeds (i.e. when plants with 0% germination were excluded from the analysis). The second part of the study investigated the effects of size variation on germinability among seeds harvested from one plant and after removal from the perianth. This variation was tested using sets of 20 size-assorted groups of 50 seeds, each originating from a particular plant; materials from six plants were tested. There were significant differences in the average germination between plants. However, in the material from the same plant there was no consistent relationship between seed mass and percentage of germination. We conclude that there exists no direct relationship between achene, perianth or seed size or mass and incidence of primary seed dormancy.

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Effects of light availability and seed size on germination and initial growth of two congeneric species of Fabaceae

Acta Botanica Mexicana ◽

10.21829/abm127.2020.1638 ◽

2020 ◽

Author(s):

Marcilio Fagundes ◽

Pablo Cuevas-Reyes ◽

Walter S. Araujo ◽

Mauricio L. Faria ◽

Henrique M. Valerio ◽

...

Keyword(s):

Light Intensity ◽

Seed Size ◽

Tree Species ◽

Seed Mass ◽

Germination Percentage ◽

High Light Intensity ◽

High Light ◽

Congeneric Species ◽

Low Light ◽

Copaifera Langsdorffii

Background and Aims: Environmental factors can interact with plant life history to determinate the reproductive strategies of adult plants and seedling recruitment. We expect that widely distributed tree species produce heavier seed and with greater variation in seed size than shrubs of restricted geographic distribution. We also predict that widely distributed tree species should be capable to germinate and develop under variable range of light conditions, while sun-adapted shrubs should germinate and develop better under high light intensity. We used as models two congeneric species of Fabaceae. Copaifera langsdorffii is a widely distributed arboreal species and C oblongifolia is a shrub with restricted distribution. Methods: Seeds were collected from two plant species in a Cerrado vegetation area, northern Minas Gerais, Brazil. The effects of light available on seed germination and seedling development was conducted in a germination chamber with controlled photoperiod, temperature and light intensity.Key results: The widely distributed tree (C. langsdorffii) had greater seed mass than the shrub (C. oblongifolia). Seeds of C. langsdorffii germinated faster under available high light, while the shrub C. oblongifolia seeds required less time to germinate under available low light and darkness. Under high light intensity, germination percentage of C. langsdorffii and C. oblongifolia seeds did not vary. However, seeds of the shrub showed a higher germination percentage under low light intensity and darkness. In general, seed mass showed a negative relationship with germination percentage, but this relationship varied in function of species and the availability of light. Copaifera langsdorffii seedlings had larger shoots and roots than C. oblongifolia. In contrast, the root:shoot ratio was higher in shrub than in tree species.Conclusions: Our results have important implications for understanding the patterns of distribution of two Copaifera species and explain the ability of C. oblongifolia to colonize disturbed areas.

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Germination and seedling establishment in cashew (Anacardium occidentale L.): An interaction between seed size, relative growth rate and seedling biomass

Journal of Plantation Crops ◽

10.19071/jpc.2017.v45.i2.3305 ◽

2017 ◽

Vol 45 (2) ◽

pp. 110

Author(s):

Babli Mog, J.D. Adiga M.G. Nayak and G.S. Mohana

Keyword(s):

Leaf Area ◽

Seed Size ◽

Seedling Establishment ◽

Seedling Survival ◽

Seedling Emergence ◽

Seed Mass ◽

Germination Percentage ◽

Mass Ratio ◽

Unit Leaf ◽

Seedling Biomass

Seeds of cashew were used to determine the effect of seed mass (5.2 to 7.8 g) on germination, seedling emergence and growth under nursery conditions. Germination percentage and germination time showed significant correlation with seed mass. Large sized seeds had higher germination percentage (81.6%) and produced more vigorous seedlings. Per cent seedling emergence was related to seed mass with large sized seeds exhibited faster emergence. Seed mass significantly affected seedling survival and survival rate was high in seedlings arising from large sized seeds (62.9%). Seedling vigor expressed in terms of shoot and root length, leaf number, leaf area and total dry matter was significantly affected by seed mass. Seedlings that emerged from large sized seeds showed better growth and produced heavier seedlings as compared to medium sized seeds. RGR showed significant variation (0.152 to 0.240 g g-1day-1) among two seed size classes positively correlated with seed mass, leaf area (LA), unit leaf rate per unit leaf area (ULRM), root to shoot ratio (R/S) and root mass ratio (RMR) and negatively with stem mass ratio (SMR). The study concluded that the seed mass and RGR have influence on seedling growth and success of seedling establishment in cashew.

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Spatial variation in seed size and seed set on spikes of some Canadian spring wheat cultivars

Canadian Journal of Plant Science ◽

10.4141/cjps91-011 ◽

1991 ◽

Vol 71 (1) ◽

pp. 95-103 ◽

Cited By ~ 3

Author(s):

Keith G. Briggs

Keyword(s):

Seed Size ◽

Seed Mass ◽

Size Variation ◽

Triticum Aestivum L ◽

Quadratic Functions ◽

Pure Stand ◽

Wheat Cultivars ◽

Frequency Distributions ◽

Significant Variance ◽

The Mean

The seed size (mass) distribution of grain on individual spikes of four Canadian wheat cultivars (Glenlea, HY320, Pitic 62 and Neepawa, Triticum aestivum L.) was determined on plant samples from two replicates of the 1984 High Yielding Wheat Cooperative trial grown at Ellerslie, Alberta. Specific grain mass was determined for individual floret locations on all spikes of each plant, and sterile floret locations were also determined. For all four cultivars the maximum amount of seed size variation from the samples was attributable to variation at the floret level, accounting for 92% of the seed size variance of Pitic 62, down to 74% for Neepawa. Neepawa differed from the other three cultivars in demonstrating a high (20%) and significant variance in seed size attributable to spikelet position. Pitic 62 was the only cultivar of the four that demonstrated significant variance (12%) due to plant differences within replicates. Consistent with previous literature, approximately 50% of total plant yield was accounted for by the mainstem spike, decreasing to 8 to 15% on the third spike. The mean number of seeds spike−1 on the mainstem was 26.8 (Neepawa), 35.9 (Glenlea), 46.8 (HY320) and 48.6 (Pitic 62), but this number decreased in response to tiller order, as did seed mass and floret fertility. Quadratic functions were calculated fitting seed mass to floret position (1 proximal to 4 distal), and were significant in all cases, with R2 values of 63% for Neepawa, 56% for Glenlea, 82% for Pitic 62 and 89% for HY320. The fitted quadratics suggest an optimization of seed size at floret site 2 for some cultivars, with a rapid decrease in seed size at floret sites 3 and 4, especially for the high-yielding cultivars Glenlea and Pitic 62. Fourth florets of the latter cultivars were shown in frequency distributions to produce seeds smaller than the mean seed size of the Neepawa seed size expected at Florets 1, 2 and 3. Large negative skewnesses for seed size for Glenlea, HY320 and Pitic 62 also underscored the tendency for the high-yielding cultivars to produce relatively large numbers of small seeds. Although determined in only one site-year, these differences in seed size distribution pattern amongst cultivars are of major significance to visual identification systems. Large-seeded, high-yielding wheats in pure stand can be expected to produce a significant number of small-seeded kernels that might be confused by visual inspection with CWRS seed type. Key words: Grain, grading, cultivar registration, seed identification, high-yielding wheats

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Seed Dispersal and Germination Traits of 70 Plant Species Inhabiting the Gurbantunggut Desert in Northwest China

The Scientific World JOURNAL ◽

10.1155/2014/346405 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 7

Author(s):

Huiliang Liu ◽

Daoyuan Zhang ◽

Xuejun Yang ◽

Zhenying Huang ◽

Shimin Duan ◽

...

Keyword(s):

Seed Dispersal ◽

Seed Size ◽

Seed Mass ◽

Northwest China ◽

Germination Percentage ◽

Gurbantunggut Desert ◽

Seed Shape ◽

Dispersal Syndromes ◽

Gurbantünggüt Desert ◽

Germination Traits

Seed dispersal and germination were examined for 70 species from the cold Gurbantunggut Desert in northwest China. Mean and range (3 orders of magnitude) of seed mass were smaller and narrower than those in other floras (5–8 orders of magnitude), which implies that selection favors relatively smaller seeds in this desert. We identified five dispersal syndromes (anemochory, zoochory, autochory, barochory, and ombrohydrochory), and anemochorous species were most abundant. Seed mass (F=3.50,P=0.01), seed size (F=8.31,P<0.01), and seed shape (F=2.62,P=0.04) differed significantly among the five dispersal syndromes and barochorous species were significantly smaller and rounder than the others. There were no significant correlations between seed mass (seed weight) (P=0.15), seed size (P=0.38), or seed shape (variance) (P=0.95) and germination percentage. However, germination percentages differed significantly among the dispersal syndromes (F=3.64,P=0.01) and seeds of ombrohydrochorous species had higher germination percentages than those of the other species. In the Gurbantunggut Desert, the percentage of species with seed dormancy was about 80%. In general, our studies suggest that adaptive strategies in seed dispersal and germination of plants in this area are closely related to the environment in which they live and that they are influenced by natural selection forces.

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Fruit size variation and its effects on germination and seedling growth in Xanthium strumarium

Canadian Journal of Botany ◽

10.1139/b83-253 ◽

1983 ◽

Vol 61 (9) ◽

pp. 2309-2315 ◽

Cited By ~ 38

Author(s):

Jesse K. Zimmerman ◽

I. Michael Weis

Keyword(s):

Seed Size ◽

Seedling Growth ◽

Root Length ◽

Germination Rate ◽

Primary Root ◽

Fruit Size ◽

Size Variation ◽

Germination Percentage ◽

Xanthium Strumarium ◽

Primary Root Length

Fruits of Xanthium strumarium L. from a population in southwestern Ontario exhibited an eightfold range in size. The effects of fruit size on seed size, germination, and seedling growth were investigated. Correlations between fruit size and seed size were strongly positive. In general, germination percentage and germination rate were both correlated positively with fruit size, although germination rate appeared to level off for the largest fruits. Cotyledon area and primary root length of newly emerged seedlings also were positively correlated with fruit size, although both variables and especially primary root length showed smaller increases over larger fruit sizes. The weights of newly emerged seedlings were highly positively correlated with fruit size. However, this relationship was not maintained for older seedlings. Weights of 15- and 30-day-old seedlings were constant over the majority of fruit sizes. This trend resulted from a negative correlation between seedling growth rate and fruit size which could, in part, be explained by a decline in the ratio of cotyledon area to the weight of newly emerged seedlings with fruit size.

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ABA Metabolism and Homeostasis in Seed Dormancy and Germination

International Journal of Molecular Sciences ◽

10.3390/ijms22105069 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5069

Author(s):

Naoto Sano ◽

Annie Marion-Poll

Keyword(s):

Seed Dormancy ◽

Current Knowledge ◽

Fine Tuning ◽

Environmental Signals ◽

Hormone Synthesis ◽

Control Seed ◽

Functional Relationships ◽

Aba Metabolism ◽

Natural Variations ◽

Germinating Seeds

Abscisic acid (ABA) is a key hormone that promotes dormancy during seed development on the mother plant and after seed dispersal participates in the control of dormancy release and germination in response to environmental signals. The modulation of ABA endogenous levels is largely achieved by fine-tuning, in the different seed tissues, hormone synthesis by cleavage of carotenoid precursors and inactivation by 8′-hydroxylation. In this review, we provide an overview of the current knowledge on ABA metabolism in developing and germinating seeds; notably, how environmental signals such as light, temperature and nitrate control seed dormancy through the adjustment of hormone levels. A number of regulatory factors have been recently identified which functional relationships with major transcription factors, such as ABA INSENSITIVE3 (ABI3), ABI4 and ABI5, have an essential role in the control of seed ABA levels. The increasing importance of epigenetic mechanisms in the regulation of ABA metabolism gene expression is also described. In the last section, we give an overview of natural variations of ABA metabolism genes and their effects on seed germination, which could be useful both in future studies to better understand the regulation of ABA metabolism and to identify candidates as breeding materials for improving germination properties.

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Morphophysiological dormancy and germination ecology in diaspores of the subtropical palm Phoenix canariensis Chabaud

Botany ◽

10.1139/cjb-2021-0126 ◽

2021 ◽

Author(s):

Lanlan He ◽

Ganesh K. Jaganathan ◽

Baolin Liu

Keyword(s):

Seed Dormancy ◽

Seedling Emergence ◽

Primary Root ◽

Germination Percentage ◽

Early Summer ◽

Germination Ecology ◽

Phoenix Canariensis ◽

Morphophysiological Dormancy ◽

Cotyledonary Petiole ◽

Seed Dormancy And Germination

The timing of germination is a crucial event in a plant’s life cycle. Seed dormancy and germination mechanisms are important factors regulating seedling emergence. Since detailed experimental evidence for germination pattern of Phoenix canariensis colonizing sub-tropical climate is scarce, we investigated seed dormancy and germination ecology of P. canariensis. We found that the embryo is underdeveloped at the time of dispersal and doubles in size before the cotyledonary petiole (CP) protrudes through the operculum. The primary root and plumule emerge from the elongated CP outside the seed. In light/dark at 30/25°C, the CP emerged from 8% of the diaspores within 30 days and from 76% within 14 weeks. Thus, 8% of the diaspores have MD and the others MPD. Removal of the pericarp and operculum resulted in 100% germination within 5 days in light/dark at 30/25°C. Cold and warm stratification as well as treatment with GA3 significantly increased the germination speed, but the final germination percentage was not significantly increased. Seed germination was synchronized in early summer when seed dormancy was released by cold stratification in the soil over winter. A remote-tubular germination type and intricate root system provide an ecological advantage to the seedling establishment.

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A model for seed size variation among plants

Evolutionary Ecology ◽

10.1007/bf01237831 ◽

1995 ◽

Vol 9 (5) ◽

pp. 495-507 ◽

Cited By ~ 16

Author(s):

Satoki Sakai

Keyword(s):

Seed Size ◽

Size Variation ◽

Seed Size Variation

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On the frost resistance of red clover with special attention to seed production

Agricultural and Food Science ◽

10.23986/afsci.71650 ◽

1966 ◽

Vol 38 (1) ◽

pp. 27-48

Author(s):

Arvi Valmari ◽

Irja Valmari

Keyword(s):

Seed Size ◽

Frost Resistance ◽

Intermediate Phase ◽

Red Clover ◽

Germination Percentage ◽

Complete Loss ◽

Stage Of Development ◽

Frost Injury ◽

Spring Cereals ◽

Clover Seed

The frost-resistance of Finnish red clover has been studied by means of experiments in a cold cabinet and on the basis of samples taken from the field. In the cold cabinet experiments the frost injury of the clover plant’s vegetative parts has reached considerable magnitude when the temperature was about 4° C. Also the unripe heads which did not die immediately could suffer so that the development of the seed stopped. Definitive death of the plants began to occur in the treatment at 5° C, though only when the soil was frozen. The plants recovered after treatment at 10° C if the soil was not frozen. In the field little frost injury of the vegetative parts occurred even with a frost of 6 to 7° C, but the unripe seeds suffered injury in that case. The germination percentage is distinctly dependent on the seed size in absence of frost. The stage of development at which more than 70 % of the corollae are light brown constituted an intermediate phase where the variation in germinative ability was great and covered, when the samples subjected to slight natural frost (–6.6° C) were taken into account, practically the entire per cent range (0—99 %). After the corollae of the heads had turned dark brown, at which time the seed had reached full weight, the seed suffered no injury from –6 to –7° C frost, and even more severe frosts could at the most cause a very slight lowering of germination percentage. Frost seems to injure the seed mainly by stopping the development of the unripe seeds. No lowering of germination from the level corresponding to the seed size has been observed in all cases nor was there any complete loss of germinative ability such as occurs with cereals. The commercial value of frost-injured red clover seed can be considerably increased by sorting. The number of hard seeds is highest in large, early harvested seed. Frost evidently causes »softening» of germinative seeds. The risk implied by frost is less in clover seed cultivation than in the cultivation of spring cereals and potatoes.

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