scholarly journals The reproductive strategy in a Chloris virgata population in response to precipitation regimes

2018 ◽  
Vol 5 (8) ◽  
pp. 180607 ◽  
Author(s):  
Wang Ying ◽  
Wang Chunxia ◽  
Zhang Jukui ◽  
Wang Chunqing
Keyword(s):  
Seed Size ◽  
Reproductive Strategy ◽  
Seed Mass ◽  
Seed Traits ◽  
Seed Number ◽  
Water Addition ◽  
Precipitation Regimes ◽  
High Precipitation ◽  
Chloris Virgata ◽  
Low Precipitation

Resource availability influences plant growth and reproduction. Here, a controlled experiment was conducted in order to evaluate the adaptation response of Chloris virgata to different precipitation conditions, and to further predict the reproductive strategy in a population of C. virgata under different precipitation regimes. Three regimes (low, typical and high) of water addition were used to simulate current precipitation patterns. In total 20 individuals for each treatment were analysed to compare tiller number, spike traits, seed traits, the relationship between seed size and seed number, and so on. In addition, the effects of different precipitation regimes on offspring vigour of C. virgata were also studied. Results indicated that tiller number, spike number, seed yield and seed number were unchanged under different water addition regimes, while seed size was about 0.5 mg at typical and high precipitation levels and was higher than that in the low precipitation level. The higher seed mass per spike and spike mass both occurred at typical and high precipitation levels. Significant positive correlations between seed mass and non-seed mass in C. virgata in response to precipitation regimes were largely allometric (size dependent), as was a significant negative correlation between seed size and seed number at low precipitation. The highest germination rates and seedling weights both occurred at typical and high precipitation levels. These findings showed that different precipitation regimes affected reproductive strategy of C. virgata. Chloris virgata will not benefit from low precipitation, while typical and high precipitation will improve seed traits and offspring vigour of this species.

scholarly journals Coupled influence of precipitation regimes and seedling emergence time on the reproductive strategy in Chloris virgata

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8476
Author(s):  
Ying Wang ◽  
Jiawei Chen ◽  
Yige Huang ◽  
Zhongsheng Mu ◽  
Changfu Wang
Keyword(s):  
Seed Size ◽  
Reproductive Strategy ◽  
Seedling Emergence ◽  
Tiller Number ◽  
Seed Number ◽  
Emergence Time ◽  
Precipitation Regime ◽  
Precipitation Regimes ◽  
Chloris Virgata ◽  
Low Precipitation

Precipitation regime and seedling emergence time both influence plant growth and reproduction. However, little attention has been given to the effects of these combined factors on the reproductive strategy of Chloris virgata, which is a vital species in Songnen grassland. Here, we simulated the changes in the precipitation regime and seedling emergence time to evaluate tiller traits and seed production. The results showed that tiller number behaved similarly among three precipitation regimes when sowed on 15 May (T1), while it increased significantly with precipitation regimes when sowed on 15 June (T2) and 15 July (T3). Tiller number decreased significantly with the seedling emergence time under the same water supply treatment. The proportional allocation of reproductive tiller number to total tiller number was significantly higher at T3 than at T1 and T2. Seed number remained similar under different precipitation regimes at T2 and T3, whereas it was significantly lower under low precipitation than under other water levels at T1. Seed number reached the maximum values at T2 under the same level of precipitation treatment. Seed size was significantly lower under low precipitation compared to other water supply treatments and the lowest values in seed size, about 0.5 mg, occurred at T2 under all the precipitation regimes. The lowest values in spike number were under low precipitation at all seedling emergence times. Seed yield exhibited similar trends with seed size under different precipitation regimes, while the greatest gains in these values were at T1 under all the precipitation regimes. Our findings showed that simulated precipitation regimes and seedling emergence time affected the reproductive strategy of C. virgata. Typical and high precipitation, as well as early seedling emergence, will improve the seed yield and seed quality in this species.

Seed mass and nutrient content in nutrient-starved tropical rainforest in Venezuela

1997 ◽  
Vol 7 (3) ◽  
pp. 269-280 ◽  
Author(s):  
Peter J. Grubb ◽  
David A. Coomes
Keyword(s):  
Seed Size ◽  
Tropical Rainforest ◽  
Forest Type ◽  
Seed Mass ◽  
Nutrient Content ◽  
Dry Mass ◽  
Seed Number ◽  
The Mean ◽  
Trees And Shrubs ◽  
Poor Soil

AbstractMean seed dry mass values were determined for 27 species of trees and shrubs in Amazonian caatinga (a forest-type especially short of nitrogen) and for 11 species in adjacent much taller forest on less poor soil. The tall trees (> 15 m) of caatinga have smaller seeds than the tall trees in adjacent forest on less infertile soil (both overall and in six taxonomically controlled comparisons), and than the tall trees in lowland rainforests elsewhere. The smaller seed size is interpreted in terms of a major advantage of keeping up seed number outweighing the marginal advantages of larger seed size. For trees of caatinga and adjacent forest considered together, there is a significantly greater concentration of P and Mg, and almost significantly greater concentration of N, in the embryo-cum-endosperm fraction of smaller-seeded species, but the content per seed of N, P and Mg is smaller in smaller seeds. The mean contribution of the seed coat (including endocarp for pyrenes) was 17% for dry mass, 3% for content of P, 10% for N and Mg, 15% for K, and 30% for Ca.

scholarly journals Forest Structure and Composition under Contrasting Precipitation Regimes in the High Mountains, Western Nepal

2021 ◽  
Vol 13 (13) ◽  
pp. 7510
Author(s):  
Kishor Prasad Bhatta ◽  
Anisha Aryal ◽  
Himlal Baral ◽  
Sujan Khanal ◽  
Amul Kumar Acharya ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Forest Structure ◽  
Tree Species ◽  
Canopy Cover ◽  
High Mountains ◽  
Precipitation Region ◽  
Precipitation Regimes ◽  
High Precipitation ◽  
Low Precipitation

The high mountains stretch over 20.4% of Nepal’s land surface with diverse climatic conditions and associated vegetation types. An understanding of tree species and forest structural pattern variations across different climatic regions is crucial for mountain ecology. This study strived to carry out a comparative evaluation of species diversity, main stand variables, and canopy cover of forests with contrasting precipitation conditions in the Annapurna range. Firstly, climate data provided by CHELSA version 1.2, were used to identify distinct precipitation regimes. Lamjung and Mustang were selected as two contrasting precipitation regions, and have average annual precipitation of 2965 mm and 723 mm, respectively. Stratified random sampling was used to study 16 plots, each measuring 500 m2 and near the tree line at an elevation range of 3000 to 4000 m across different precipitation conditions. In total, 870 trees were identified and measured. Five hemispherical photos using a fisheye lens were taken in each plot for recording and analyzing canopy cover. Margalef’s index was used to measure species richness, while two diversity indices: the Shannon–Wiener Index and Simpson Index were used for species diversity. Dominant tree species in both study regions were identified through the Important Value Index (IVI). The Wilcoxon rank-sum test was employed to determine the differences in forest structure and composition variables between the two precipitation regimes. In total, 13 species were recorded with broadleaved species predominating in the high precipitation region and coniferous species in the low precipitation region. Higher species richness and species diversity were recorded in the low precipitation region, whereas the main stand variables: basal area and stem density were found to be higher in the high precipitation region. Overall, an inverse J-shaped diameter distribution was found in both precipitation regions signifying uneven-aged forest. A higher proportion of leaning and buttressed trees were recorded in the high precipitation region. However, similar forest canopy cover conditions (>90%) were observed in both study regions. The findings of this research provide a comprehensive narrative of tree species and forest structure across distinct precipitation regimes, which can be crucial to administrators and local people for the sustainable management of resources in this complex region.

scholarly journals Seed size, number and strategies in annual plants: a comparative functional analysis and synthesis

2020 ◽  
Vol 126 (7) ◽  
pp. 1109-1128
Author(s):  
John G Hodgson ◽  
Gabriel Montserrat Marti ◽  
Bozena Šerá ◽  
Glynis Jones ◽  
Amy Bogaard ◽  
...  
Keyword(s):  
Life History ◽  
Seed Size ◽  
Seed Yield ◽  
Gold Standard ◽  
Seed Mass ◽  
Positive Function ◽  
Plant Size ◽  
Seed Number ◽  
Negative Function ◽  
Ecological Importance

Abstract Background and Aims Plants depend fundamentally on establishment from seed. However, protocols in trait-based ecology currently estimate seed size but not seed number. This can be rectified. For annuals, seed number should simply be a positive function of vegetative biomass and a negative function of seed size. Methods Using published values of comparative seed number as the ‘gold standard’ and a large functional database, comparative seed yield and number per plant and per m2 were predicted by multiple regression. Subsequently, ecological variation in each was explored for English and Spanish habitats, newly calculated C-S-R strategies and changed abundance in the British flora. Key Results As predicted, comparative seed mass yield per plant was consistently a positive function of plant size and competitive ability, and largely independent of seed size. Regressions estimating comparative seed number included, additionally, seed size as a negative function. Relationships differed numerically between regions, habitats and C-S-R strategies. Moreover, some species differed in life history over their geographical range. Comparative seed yield per m2 was positively correlated with FAO crop yield, and increasing British annuals produced numerous seeds. Nevertheless, predicted values must be viewed as comparative rather than absolute: they varied according to the ‘gold standard’ predictor used. Moreover, regressions estimating comparative seed yield per m2 achieved low precision. Conclusions For the first time, estimates of comparative seed yield and number for >800 annuals and their predictor equations have been produced and the ecological importance of these regenerative traits has been illustrated. ‘Regenerative trait-based ecology’ remains in its infancy, with work needed on determinate vs. indeterminate flowering (‘bet-hedging’), C-S-R methodologies, phylogeny, comparative seed yield per m2 and changing life history. Nevertheless, this has been a positive start and readers are invited to use estimates for >800 annuals, in the Supplementary data, to help advance ‘regenerative trait-based ecology’ to the next level.

Reproduction strategy of Chloris virgata under simulated atmospheric nitrogen deposition

2015 ◽  
Vol 66 (5) ◽  
pp. 516 ◽  
Author(s):  
Wang Changfu ◽  
Wang Ying
Keyword(s):  
Seed Size ◽  
N Deposition ◽  
Control Treatment ◽  
Reproductive Pattern ◽  
Atmospheric Nitrogen ◽  
Seed Number ◽  
Atmospheric N Deposition ◽  
Seed Vigour ◽  
Rhodes Grass ◽  
Chloris Virgata

Atmospheric nitrogen (N) deposition is an important issue of global climate change and it will significantly affect plant growth and reproduction, resulting in damage to ecological systems. However, little attention has been given to the effects of this factor on plant reproductive strategies. We investigated how variation in atmospheric N deposition affects the reproductive strategy of Chloris virgata (feathertop Rhodes grass). We simulated atmospheric N deposition to evaluate the trade-off between seed size and seed number, as well as its effects on offspring vigour. We found significant negative correlations between seed size and seed number per spike in the control and 20.0 g N m–2 treatments, as well as between seed size and seed number per plant in the control treatment. Seed number and seed weight per spike behaved similarly and were significantly lower in the control and 20.0 g N m–2 treatments than in the other N supply treatments. Spike number and seed yield behaved similarly, and the greatest gains in these values occurred from 2.5 to 20.0 g N m–2. Seed size reached its maximum values at low and high N levels, whereas seed N concentrations increased with N level. Although the germination percentage remained stable under different N levels, the highest germination rate occurred in the control treatment. Our findings showed that simulated atmospheric N deposition affected the reproductive pattern and seed vigour of C. virgata.

scholarly journals The ecology and quantitative genetics of seed and seedling traits in upland and lowland ecotypes of a perennial grass

2021 ◽  
Author(s):  
Samsad Razzaque ◽  
Tom Juenger
Keyword(s):  
Local Adaptation ◽  
Seed Size ◽  
Field Experiments ◽  
Seed Mass ◽  
Strong Support ◽  
Directional Selection ◽  
Seedling Vigor ◽  
Seed Traits ◽  
Ecotypic Differentiation ◽  
Seed Trait

Plants have evolved diverse reproductive allocation strategies and seed traits to aid in dispersal, persistence in the seed bank, and establishment. In particular, seed size, dormancy, and early seedling vigor are thought to be key functional traits with important recruitment and fitness consequences across abiotic stress gradients. Selection for favored seed-trait combinations, or against maladaptive combinations, is likely an important driver shaping recruitment strategies. Here, we test for seed-trait plasticity and local adaptation in contrasting upland and lowland ecotypes of Panicum hallii with field experiments in native versus foreign habitats. Furthermore, we test whether seed traits have been under directional selection in P. hallii using the v-test (Fraser 2020) based on trait variance in a genetic cross. Finally, we evaluate the genetic architecture of ecotypic divergence for these traits with Quantitative Trait Locus (QTL) mapping. Field experiments reveal little plasticity but support a hypothesis of local adaptation among ecotypes based on recruitment. Patterns of segregation within recombinant hybrids provides strong support for directional selection driving ecotypic divergence in seeds traits. Genetic mapping revealed a polygenic architecture with evidence of genetic correlation between seed mass, dormancy, and seedling vigor. Our results suggest that the evolution of these traits may involve constraints that affect the direction of adaptive divergence. For example, seed size and germination percentage shared two colocalized QTL with antagonistic additive effects. This supports the hypothesis of a functional genetic relationship between these traits, resulting in either large seed/strong dormancy or small seed/weak dormancy trait combinations. Overall, our study provides insights into the factors facilitating and potentially constraining ecotypic differentiation in seed traits.

scholarly journals Genome-wide association study identified candidate genes for seed size and seed composition improvement in M. truncatula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhijuan Chen ◽  
Vanessa Lancon-Verdier ◽  
Christine Le Signor ◽  
Yi-Min She ◽  
Yun Kang ◽  
...  
Keyword(s):  
Association Study ◽  
Protein Content ◽  
Seed Size ◽  
Seed Protein ◽  
Genome Wide Association Study ◽  
Genome Wide Association ◽  
Strong Positive Correlation ◽  
Seed Composition ◽  
Seed Traits ◽  
Genome Wide

AbstractGrain legumes are highly valuable plant species, as they produce seeds with high protein content. Increasing seed protein production and improving seed nutritional quality represent an agronomical challenge in order to promote plant protein consumption of a growing population. In this study, we used the genetic diversity, naturally present in Medicago truncatula, a model plant for legumes, to identify genes/loci regulating seed traits. Indeed, using sequencing data of 162 accessions from the Medicago HAPMAP collection, we performed genome-wide association study for 32 seed traits related to seed size and seed composition such as seed protein content/concentration, sulfur content/concentration. Using different GWAS and postGWAS methods, we identified 79 quantitative trait nucleotides (QTNs) as regulating seed size, 41 QTNs for seed composition related to nitrogen (i.e. storage protein) and sulfur (i.e. sulfur-containing amino acid) concentrations/contents. Furthermore, a strong positive correlation between seed size and protein content was revealed within the selected Medicago HAPMAP collection. In addition, several QTNs showed highly significant associations in different seed phenotypes for further functional validation studies, including one near an RNA-Binding Domain protein, which represents a valuable candidate as central regulator determining both seed size and composition. Finally, our findings in M. truncatula represent valuable resources to be exploitable in many legume crop species such as pea, common bean, and soybean due to its high synteny, which enable rapid transfer of these results into breeding programs and eventually help the improvement of legume grain production.

Sign in / Sign up

Export Citation Format

Share Document