Universidade Federal de Lavras - UFLA, Departamento de Biologia, Setor de Botânica, Lavras, MG, Brasil.
Universidade Federal de Lavras - UFLA, Departamento de Biologia, Programa de Pós-graduação em Genética, Lavras, MG, Brasil.
Braz J Biol. 2021 May 10;82:e237575. doi: 10.1590/1519-6984.237575. eCollection 2021.
Resource allocation to reproduction can change depending on size, as predicted by the size-dependent sex allocation. This theory is based on the fact that small individuals will invest in the allocation of sex with lower cost of production, usually male gender. In plants, there are some andromonoecy species, presence of hermaphrodite and male flowers in the same individual. Andromonoecy provides a strategy to optimally allocate resources to male and female function, evolving a reproductive energy-saving strategy. Thus, our objective was to investigate the size-dependent sex allocation in Solanum lycocarpum St. Hil. We tested the hypothesis that plants with larger size will invest in the production of hermaphrodite flowers, because higher individuals have greater availability of resources to invest in more complex structures involving greater energy expenditure. The studied species was S. lycocarpum, an andromonoecious species. From June 2016 to March 2017 the data were collected in 38 individuals, divided in two groups: the larger plant group (n=18; height=3-5 m) and the smaller plant group (n=20; height=1-2 m).Our data show that there was effect of plant size on the flower production and the sexual gender allocation. The larger plants showed more flowers and higher production of hermaphrodite flowers. Furthermore, in the flower scale, we observed allometric relationship among the flower's traits with proportional investments in biomass, anther size and gynoecium size. Our results are in agreement with size-dependent sex allocation theory and andromonoecy hypothesis related to mechanisms for optimal resource allocation to male and female function.
资源分配给繁殖可以根据大小而改变，这是由大小依赖的性别分配所预测的。这一理论基于这样一个事实，即小个体将投资于生产成本较低的性别分配，通常是雄性。在植物中，存在一些雌雄同株单性花物种，即在同一个体中存在雌性和雄性花。雌雄同株单性花提供了一种最佳分配资源用于雄性和雌性功能的策略，进化出了一种节能的生殖策略。因此，我们的目标是研究 Solanum lycocarpum St. Hil 中的大小依赖的性别分配。我们检验了这样一个假设，即较大的植物将投资于生产雌性花，因为较高的个体具有更多的资源可用性，可以投资于更复杂的结构，涉及更高的能量消耗。所研究的物种是雌雄同株单性花的 Solanum lycocarpum。2016 年 6 月至 2017 年 3 月，在 38 个个体中收集数据，分为两组：较大的植物组（n=18；高度=3-5 m）和较小的植物组（n=20；高度=1-2 m）。我们的数据表明，植物大小对花的产生和性别分配有影响。较大的植物产生更多的花和更高比例的雌性花。此外，在花的鳞片中，我们观察到花的性状与生物量、花药大小和雌蕊大小的比例投资之间存在着一种同态关系。我们的结果与大小依赖的性别分配理论和与雄性和雌性功能的最佳资源分配机制相关的雌雄同株单性花假说一致。
