Zhang Yonghua, Lin Wei, Chu Chengjin, Ni Ming
College of Life and Environmental Sciences, Wenzhou University, Wenzhou, 325000, China.
State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-sen University, Guangzhou, China.
Am J Bot. 2023 Apr;110(4):e16153. doi: 10.1002/ajb2.16153. Epub 2023 Apr 3.
Dioecious trees are important components of many forest ecosystems. Outbreeding advantage and sexual dimorphism are two major mechanisms that explain the persistence of dioecious plants; however, they have rarely been studied in dioecious trees.
We investigated the influence of sex and genetic distance between parental trees (GDPT) on the growth and functional traits of multiple seedlings of a dioecious tree, Diospyros morrisiana.
We found significant positive relationships between GDPT and seedling sizes and tissue density. However, the positive outbreeding effects on seedling growth mainly manifested in female seedlings, but were not prominent in males. Among seedlings, the male ones generally had higher biomass and leaf area than female seedlings, but such differences diminished as GDPT increased.
Our research highlights that outbreeding advantage in plants can be sex-specific and that sexual dimorphism begins from the seedling stage of dioecious trees.
雌雄异株树木是许多森林生态系统的重要组成部分。远交优势和性别二态性是解释雌雄异株植物得以延续的两个主要机制；然而，它们在雌雄异株树木中很少得到研究。
我们研究了性别以及亲本树木之间的遗传距离（GDPT）对一种雌雄异株树木——山榄科乌木属树木多株幼苗的生长和功能性状的影响。
我们发现GDPT与幼苗大小和组织密度之间存在显著的正相关关系。然而，远交对幼苗生长的积极影响主要体现在雌株幼苗上，而在雄株幼苗中并不显著。在幼苗中，雄株通常比雌株具有更高的生物量和叶面积，但随着GDPT的增加，这种差异会减小。
我们的研究强调，植物中的远交优势可能具有性别特异性，并且性别二态性从雌雄异株树木的幼苗阶段就开始了。
