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Eduardo Fernndez‐Pascual Efisio Mattana Hugh W. Pritchard 《Biological reviews of the Cambridge Philosophical Society》2019,94(2):439-456
Plant persistence and migration in face of climate change depends on successful reproduction by seed, a central aspect of plant life that drives population dynamics, community assembly and species distributions. Plant reproduction by seed is a chain of physiological processes, the rates of which are a function of temperature, and can be modelled using thermal time models. Importantly, while seed reproduction responds to its instantaneous thermal environment, there is also evidence of phenotypic plasticity in response to the thermal history experienced by the plant's recent ancestors, by the reproducing plant since seedling establishment, and by its seeds both before and after their release. This phenotypic plasticity enables a thermal memory of plant reproduction, which allows individuals to acclimatise to their surroundings. This review synthesises current knowledge on the thermal memory of plant reproduction by seed, and highlights its importance for modelling approaches based on physiological thermal time. We performed a comprehensive search in the Web of Science and analysed 533 relevant articles, of which 81 provided material for a meta‐analysis of thermal memory in reproductive functional traits based on the effect size Zr. The articles encompassed the topics of seed development, seed yield (mass and number), seed dormancy (physiological, morphological and physical), germination, and seedling establishment. The results of the meta‐analysis provide evidence for a thermal memory of seed yield, physiological dormancy and germination. Seed mass and physiological dormancy appear to be the central hubs of this memory. We argue for integrating thermal memory into a predictive framework based on physiological time modelling. This will provide a quantitative assessment of plant reproduction, a complex system that integrates past and present thermal inputs to achieve successful reproduction in changing environments. The effects of a warming environment on plant reproduction cannot be reduced to a qualitative interpretation of absolute positives and negatives. Rather, these effects need to be understood in terms of changing rates and thresholds for the physiological process that underlie reproduction by seed. 相似文献
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Diane L. Byers Gerrit A. J. Platenkamp Ruth G. Shaw 《Evolution; international journal of organic evolution》1997,51(5):1445-1456
A growing body of evidence indicates that phenotypic selection on juvenile traits of both plants and animals may be considerable. Because juvenile traits are typically subject to maternal effects and often have low heritabilities, adaptive responses to natural selection on these traits may seem unlikely. To determine the potential for evolutionary response to selection on juvenile traits of Nemophila menziesii (Hydrophyllaceae), we conducted two quantitative genetic studies. A reciprocal factorial cross, involving 16 parents and 1960 progeny, demonstrated a significant maternal component of variance in seed mass and additive genetic component of variance in germination time. This experiment also suggested that interaction between parents, though small, provides highly significant contributions to the variance of both traits. Such a parental interaction could arise by diverse mechanisms, including dependence of nuclear gene expression on cytoplasmic genotype, but the design of this experiment could not distinguish this from other possible causes, such as effects on progeny phenotype of interaction between the environmental conditions of both parents. The second experiment, spanning three generations with over 11,000 observations, was designed for investigation of the additive genetic variance in maternal effect, assessment of paternal effects, as well as further partitioning of the parental interaction identified in the reciprocal factorial experiment. It yielded no consistent evidence of paternal effects on seed mass, nor of parental interactions. Our inference of such interaction effects from the first experiment was evidently an artifact of failing to account for the substantial variance among fruits within crosses. The maternal effect was found to have a large additive genetic component, accounting for at least 20% of the variation in individual seed mass. This result suggests that there is appreciable potential for response to selection on seed mass through evolution of the maternal effect. We discuss aspects that may nevertheless limit response to individual selection on seed mass, including trade-offs between the size of individual seeds and germination time and between the number of seeds a maternal plant can mature and their mean size. 相似文献
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植物功能性状 (plant functional trait)是近年来生态学研究的热点。以云南怒江和澜沧江干热河谷36种木本植物为研究对象,选取比叶面积 (SLA)、植株高 (H) 和种子干重 (SM) 3个功能性状,研究它们的相互关系,比较其在河谷间、河谷内的差异。结果表明:1)两个河谷内36种木本植物的以上3种功能性状间没有显著的相关性 (P值分别为0.8739,0.5763,0.5517);2)河谷间的比叶面积存在显著差异 (P=0.02944),植株高和种子干重无显著差异 (P分别为0.4070, 0.8867);3)两个河谷内木本植物功能性状中,种子干重差异最大,植株高次之,比叶面积最小。 相似文献
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Active restoration of grassland ecosystems often requires the addition of species as seeds. However, knowledge of seed germination and initial performance of native species are still lacking in many regions, including the Brazilian grasslands. Regenerative traits (such as seed traits) have the potential to predict performance parameters related to the initial establishment of a species in a given environment. This study aimed to test the potential of regenerative traits as predictors of the performance of grassland species, information which may be useful for ecological restoration purposes. Using 15 grassland species, we carried out three parallel experiments at different conditions: cabinet, greenhouse, and field. Three performance parameters were evaluated: final germination percentage (FGP), germination rate index (GRI), and survival rate. The suitability of seed traits (mass, area, and shape) as predictors of performance parameters was evaluated for each experiment using linear regression models. Performance parameters varied among the species and experiments, but seed mass and shape slightly influenced GRI. Seed area had a positive effect on GRI, and there was a significant interaction between seed circularity and mass, which improved the GRI of round, heavy seeds. FGP and survival rate were not predicted by any of the traits. Our study highlights the importance of testing fitness–trait relationships under field conditions, which may reflect the real challenges species will face in restoration projects. Our results reinforce the need of considering regenerative traits and interaction factors to improve the understanding and prediction of the initial performance of species. 相似文献
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连香树(Cercidiphyllum japonicum)是第三纪孑遗植物, 存在严重的幼苗更新限制。为验证生活史早期(种子萌发)限制中国分布区北缘连香树种群幼苗更新, 并探讨其主要成因, 本研究在秦岭和太行山脉采集不同种源地的种子, 测定其形态性状、营养元素含量和质量、不同贮存时间的活力及不同温度条件下的萌发性状, 通过方差分析、相关分析等方法对不同种源地的种子性状进行分析。结果表明: 在中国分布区北缘, 其种子长度(P < 0.001)、萌发率(P < 0.001)、平均萌发时间(P < 0.001)、氮(P < 0.05)和磷含量(P < 0.001)在不同种源间存在显著差异; 而在区域尺度上(秦岭与太行山), 仅种子碳含量存在显著差异(P < 0.01)。天水种群的种子萌发率最高(21.77%), 平均萌发时间最长(11.12 d); 栾川的萌发率最低(1.38%), 平均萌发时间最短(3.47 d)。在25℃条件下, 济源种群的种子萌发率显著高于10℃、15℃和20℃条件下(P < 0.05), 而其他种源地的萌发率在不同温度条件下无显著差异。在4个温度条件下, 栾川种群种子的初始萌发时间无显著差异, 而其他4个种源地的初始萌发时间都随温度升高而缩短。相关分析结果表明, 种子萌发率与种子活力密切相关, 而种子活力与种子质量、种子的氮和磷含量显著相关。在中国分布区北缘, 连香树种子的自身属性(质量、氮和磷含量)通过影响种子活力间接影响萌发率; 且种子萌发对温度的响应主要表现在萌发时间上。本研究证实种子萌发是限制连香树种群幼苗更新的关键阶段, 主要原因如下: (1)连香树种子在9月成熟后, 10月的温度仍适宜种子萌发, 但较短生长期的幼苗在冬季低温下不能存活; (2)连香树种子萌发率低(14.4%); (3)第二年春天种子活力骤降。 相似文献
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M. Gianella A. Balestrazzi A. Pagano J. V. Müller A. C. Kyratzis D. Kikodze M. Canella A. Mondoni G. Rossi F. Guzzon 《Plant biology (Stuttgart, Germany)》2020,22(2):191-202
- Crop wild relatives are fundamental genetic resources for crop improvement. Wheat wild relatives often produce heteromorphic seeds that differ in morphological and physiological traits. Several Aegilops and Triticum species possess, within the same spikelet, a dimorphic seed pair, with one seed being larger than the other. A comprehensive analysis is needed to understand which traits are involved in seed dimorphism and if these aspects of variation in dimorphic pairs are functionally related.
- To this end, dispersal units of Triticum urartu and five Aegilops species were X‐rayed and the different seed morphs weighed. Germination tests were carried out on seeds, both dehulled and left in their dispersal units. Controlled ageing tests were performed to detect differences in seed longevity among seed morphs, and the antioxidant profile was assessed in terms of antioxidant compounds equipment and expression of selected antioxidant genes. We used PCA to group seed morphs sharing similar patterns of germination traits, longevity estimates and antioxidant profile.
- Different seed morphs differed significantly in terms of mass, final germination, germination timing, longevity estimates and antioxidant profile in most of the tested species. Small seeds germinated slower, had lower germination when left in their dispersal units, a higher antioxidant potential and were longer‐lived than large seeds. The antioxidant gene expression varied between morphs, with different patterns across species but not clearly reflecting the phenotypic observations.
- The results highlight different trait trade‐offs in dimorphic seeds of Aegilops and T. urartu, affecting their germination phenology and longevity, thereby resulting in recruitment niche differentiation.
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- Seed germination, a critical stage of the plant life cycle providing a link between seeds and seedlings, is commonly temperature-dependent. The global average surface temperature is expected to rise, but little is known about the responses of seed germination of woody plants in temperate forests to warming.
- In the present study, dried seeds of 23 common woody species in temperate secondary forests were incubated at three temperature sequences without cold stratification and after experiencing cold stratification. We calculated five seed germination indices and the comprehensive membership function value that summarized the above indicators.
- Compared to the control, +2 and +4 °C treatments without cold stratification shortened germination time by 14% and 16% and increased the germination index by 17% and 26%, respectively. For stratified seeds, +4 °C treatment increased germination percentage by 49%, and +4 and +2 °C treatments increased duration of germination and the germination index, and shortened mean germination time by 69%, 458%, 29% and 68%, 110%, 12%, respectively. The germination of Fraxinus rhynchophylla and Larix kaempferi were most sensitive to warming without and with cold stratification, respectively. Seed germination of shrubs was the least sensitive to warming among functional types.
- These findings indicate warming (especially extreme warming) will enhance the seedling recruitment of temperate woody species, primarily via shortening the germination time, particularly for seeds that have undergone cold stratification. In addition, shrubs might narrow their distribution range
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J.A. Raven 《Plant Ecology & Diversity》2013,6(2):219-225
Background: Although fire is an important factor in determining cerrado vegetation, information about its effect on seed banks is sparse. Cerrado fires are rapidly moving surface fires with low residence time, producing only short-term heating of the uppermost centimetres of the soil. However, the reduction in vegetation cover and deposition of ashes increases the daily amplitude of soil temperature by as much as 35 °C.Aims: To assess the effect of post-fire daily soil temperatures on the germination of one alien and nine native grasses.Methods: Seeds were stored at alternating temperatures of 45 ºC/10 ºC (10 h/14 h) for 7 d or 30 d, simulating two different storage times in the soil seed bank before the onset of the rainy season. Germination was monitored over 30 d.Results: The variation in temperature had a significant effect on the rate of seed germination in some species, either enhancing it (Aristida setifolia) or reducing it (Schizachyrium sanguineum). Increased storage time reduced the viability of S. sanguineum and Echinolaena inflexa. The invasive Melinis minutiflora had the highest germination rate and it also showed the best toleration of post-fire conditions (45 ºC/10 ºC) after 7 d, with significant reduction in the germination time after 30 d.Conclusions: Fire seems to have a significant effect in the early life of cerrado grasses. Some native species responded positively to temperature oscillation, suggesting that they should be better prepared to compete with alien species after a fire, with more of their seeds germinating and/or at a more rapid rate. 相似文献
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Emma Ladouceur Costantino Bonomi Helge Bruelheide Jitka Klime&#x;ov Sabina Burrascano Peter Poschlod Maria Tudela‐Isanta Pietro Iannetta Andrea Mondoni Bernard Amiaud Bruno E. L. Cerabolini Johannes Hans C. Cornelissen Joseph Craine Frdrique Louault Vanessa Minden Kinga
llerer Vladimir Onipchenko Nadejda A. Soudzilovskaia Borja Jimnez‐Alfaro 《植被学杂志》2019,30(5):777-788
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Ane Kirstine Brunbjerg Jeannine Cavender-Bares Wolf L. Eiserhardt Rasmus Ejrn s Lonnie W. Aarssen Hannah L. Buckley Estelle Forey Florian Jansen Jens Kattge Cynthia Lane Roy A. Lubke Angela T. Moles Ana Laura Monserrat Robert K. Peet Julissa Roncal Louise Wootton Jens-Christian Svenning 《Journal of Plant Ecology》2014,7(2):101
Aims Studies integrating phylogenetic history and large-scale community assembly are few, and many questions remain unanswered. Here, we use a global coastal dune plant data set to uncover the important factors in community assembly across scales from the local filtering processes to the global long-term diversification and dispersal dynamics. Coastal dune plant communities occur worldwide under a wide range of climatic and geologic conditions as well as in all biogeographic regions. However, global patterns in the phylogenetic composition of coastal dune plant communities have not previously been studied.Methods The data set comprised vegetation data from 18463 plots in New Zealand, South Africa, South America, North America and Europe. The phylogenetic tree comprised 2241 plant species from 149 families. We calculated phylogenetic clustering (Net Relatedness Index, NRI, and Nearest Taxon Index, NTI) of regional dune floras to estimate the amount of in situ diversification relative to the global dune species pool and evaluated the relative importance of land and climate barriers for these diversification patterns by geographic analyses of phylogenetic similarity. We then tested whether dune plant communities exhibit similar patterns of phylogenetic structure within regions. Finally, we calculated NRI for local communities relative to the regional species pool and tested for an association with functional traits (plant height and seed mass) thought to vary along sea–inland gradients.Important findings Regional species pools were phylogenetically clustered relative to the global pool, indicating regional diversification. NTI showed stronger clustering than NRI pointing to the importance of especially recent diversifications within regions. The species pools grouped phylogenetically into two clusters on either side of the tropics suggesting greater dispersal rates within hemispheres than between hemispheres. Local NRI plot values confirmed that most communities were also phylogenetically clustered within regions. NRI values decreased with increasing plant height and seed mass, indicating greater phylogenetic clustering in communities with short maximum height and good dispersers prone to wind and tidal disturbance as well as salt spray, consistent with environmental filtering along sea–inland gradients. Height and seed mass both showed significant phylogenetic signal, and NRI tended to correlate negatively with both at the plot level. Low NRI plots tended to represent coastal scrub and forest, whereas high NRI plots tended to represent herb-dominated vegetation. We conclude that regional diversification processes play a role in dune plant community assembly, with convergence in local phylogenetic community structure and local variation in community structure probably reflecting consistent coastal-inland gradients. Our study contributes to a better understanding of the globally distributed dynamic coastal ecosystems and the structuring factors working on dune plant communities across spatial scales and regions. 相似文献
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S. J. McInnes R. Tangney J. J. Brophy P. Thordarson M. K. J. Ooi 《Plant biology (Stuttgart, Germany)》2023,25(2):268-275
- Seed dormancy is the key driver regulating seed germination, hence is fundamental to the seedling recruitment life-history stage and population persistence. However, despite the importance of physical dormancy (PY) in timing post-fire germination, the mechanism driving dormancy-break within seed coats remains surprisingly unclear. We suggest that seed coat chemistry may play an important role in controlling dormancy in species with PY. In particular, seed coat fatty acids (FAs) are hydrophobic, and have melting points within the range of seed dormancy-breaking temperatures. Furthermore, melting points of saturated FAs increase with increasing carbon chain length. We investigated whether fire could influence seed coat FA profiles and discuss their potential influence on dormancy mechanisms.
- Seed coat FAs of 25 species within the Faboideae, from fire-prone and fire-free ecosystems, were identified and quantified through GC–MS. Fatty acid profiles were interpreted in the context of species habitat and interspecific variation.
- Fatty acid compositions were distinct between species from fire-prone and fire-free habitats. Fire-prone species tended to have longer saturated FA chains, a lower ratio of saturated to unsaturated FA, and a slightly higher relative amount of FAs compared to fire-free species.
- The specific FA composition of seed coats of fire-prone species indicated a potential role of FAs in dormancy mechanisms. Overall, the distinct FA composition between fire-prone and fire-free species suggests that chemistry of the seed coat may be under selection pressure in fire-prone ecosystems.
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Substantial intra‐specific trait variation exists within plant communities, and in theory this variation could influence community dynamics. Although recent research has focused on intra‐specific variation in traits themselves, it is the influence of this variation on plant performance that makes intra‐specific trait variation relevant to ecological dynamics within or among species. Understanding the links between trait and performance variation, and the role of traits in mediating relationships among multiple components of performance, is critical for assessing the importance of intra‐specific trait variation for community dynamics. Seed size is thought to affect aspects of plant performance including fecundity, seedling growth, dispersal and tolerance of natural enemies. For two tropical tree species, we assessed how seed size was related to performance variation within each species and determined whether intra‐specific trait variation mediates intra‐specific performance tradeoffs. We used field seed rain collection to characterize size‐dependent outcomes of dispersal, sowed seeds of known size in soil collected near or far from conspecifics to characterize susceptibility to soil pathogens, and monitored growth of seedlings from seeds of known size. We found that intra‐specific seed size variation caused intra‐specific performance variation. The degree of trait‐based performance variation was consistently smaller than the degree of trait variation, and seed size influenced different components of performance for each species. One species exhibited a tradeoff in which small seeds had a fecundity advantage (more seedlings per unit reproductive mass) but produced smaller seedlings, whereas the other species exhibited a tradeoff in which small seeds dispersed to areas of low conspecific density but were less tolerant of density‐responsive natural enemies. Our results indicate that a single trait can influence multiple components of performance and can mediate different tradeoffs in co‐occurring species. Complex and heterogeneous effects of a single trait in multidimensional niche space may favour inter‐specific niche differentiation and coexistence. 相似文献
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等渗的盐分和水分胁迫对杠柳种子萌发的影响 总被引：3，自引：3，他引：3
通过等渗的NaCl和PEG溶液模拟盐分和水分胁迫,设置渗透梯度,在控制条件下对杠柳种子的萌发过程中总萌发率、幼苗鲜重、胚根生长、种子活力、发芽值等指标系统研究,对种子萌发率与渗透势之间关系进行回归分析,主要结果包括：（1）杠柳种子萌发过程中总萌发率、幼苗鲜重、活力指数和发芽值四项指标均随NaCl和PEG溶液的渗透势降低逐渐下降,综合研究活力指数和发芽值表明渗透势≥-0.5 MPa和≤-1.4 MPa时,PEG对种子萌发抑制作用大于NaCl,其他情况相反;（2）杠柳种子逐日萌发率和胚根日变化研究表明,与NaCl相比,PEG推迟杠柳种子萌发,并且对胚根增长抑制作用较大;（3）建立盐分和水分胁迫条件下种子萌发率与渗透势回归方程,发现杠柳种子在PEG胁迫下的萌发临界值和极限值为-1.0和-1.4 MPa,在NaCl胁迫下是-0.9和-1.3 MPa,解除胁迫条件,不同处理的杠柳种子复水萌发率均达到100%。说明杠柳具有良好的耐盐抗旱的特性。 相似文献
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红外相机技术目前已成为调查、记录陆生大中型兽类和地栖鸟类的最有效方法之一, 为自然保护地的生物多样性编目、野生动物本底调查提供了可靠的数据基础。老河沟保护地位于四川省平武县, 地处岷山山脉中段, 面积110 km2, 是大熊猫(Ailuropoda melanoleuca)、川金丝猴(Rhinopithecus roxellana)、红喉雉鹑(Tetraophasis obscurus)等珍稀濒危野生动物的自然栖息地。本文汇总、整理了老河沟保护地2011-2015年的红外相机监测记录, 提供了完整的红外相机监测数据集。数据集包括红外相机有效位点130个, 海拔跨度1,317-3,265 m, 总有效相机工作日10,185 d。红外相机拍摄记录159,694条, 其中兽类记录91,839条, 独立有效照片3,017张, 包括分属5目15科的野生兽类28种; 鸟类记录37,775条, 独立有效照片1,311张, 包括分属7目19科的野生鸟类60种; 两栖类记录8条, 独立有效照片2张, 包括1目1科1种; 家畜记录47条, 独立有效照片5张。 相似文献