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Article|01 Jul 2021|OPEN
Sexual competition and kin recognition co-shape the traits of neighboring dioecious Diospyros morrisiana seedlings
Yulin He1, Han Xu2, Hanlun Liu1, Meiling Luo1, Chengjin Chu1 & Suqin Fang1,
1State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
2 Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou 510520, China

Horticulture Research 8,
Article number: 162 (2021)
doi: 10.1038/hortres.2021.162
Views: 150

Received: 19 Sep 2020
Revised: 10 May 2021
Accepted: 15 May 2021
Published online: 01 Jul 2021

Abstract

Plants respond differently to the identity of their neighbors, such as their sex and kinship, showing plasticity in their traits. However, how the functional traits of dioecious trees are shaped by the recognition of neighbors with different sex and kinship remains unknown. In this study, we set up an experiment with different kin/nonkin and inter/intrasexual combinations for a dioecious tree species, Diospyros morrisiana. The results showed that plants grew better with nonkin and intrasexual neighbors than with kin and intersexual neighbors. Kin combinations had significantly shorter root length in the resource-overlapping zone than nonkin combinations, suggesting that kin tended to reduce competition by adjusting their root distribution, especially among female siblings. Our study suggested that the seedling growth of D. morrisiana was affected by both the relatedness and sexual identity of neighboring plants. Further analysis by gas chromatography-mass spectrometry showed that the root exudate composition of female seedlings differed from that of male seedlings. Root exudates may play important roles in sex competition in dioecious plants. This study indicates that sex-specific competition and kin recognition interact and co-shape the traits of D. morrisiana seedlings, while intrasexual and nonkin neighbors facilitate the growth of seedlings. Our study implies that kin- and sex-related interactions depend on different mechanisms, kin selection, and niche partitioning, respectively. These results are critical for understanding how species coexist and how traits are shaped in nature.