Male-biased sex allocation in late-blooming flowers driven by resource limitation in the clonal perennial Aconitum kusnezoffii (Ranunculaceae)  

作　　者：Xing-Yue M.Ge Han-Shu Lu Hao Tian Yue Wu Da-Yong Zhang Wan-Jin Liao 

机构地区：[1]State Key Laboratory of Earth Surface Processes&Resource Ecology and MoE Key Laboratory for Biodiversity Science and Ecological Engineering,Collegeof LifeSciences,BeijingNormal University,Beijing1oo875,China

出　　处：《Journal of Systematics and Evolution》2022年第6期1393-1404,共12页植物分类学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(No.31770253);the 111 project(No.B13008);the Beiing Advanced Innovation Program for Land Surface Science.

摘　　要：Flowering phenology and clonal growth are known to affect resource and pollen availability, and therefore select for adaptive or constrained sex allocation strategies to some degree. However, the consequences of temporal sex allocation patterns for reproductive fitness across the flower, inflorescence, and genet levels have rarely been examined. Moreover, experimental tests of the underlying regulatory mechanisms are scarce. We examined the association of flowering phenology and inflorescence position with temporal sex allocation and reproductive success in the protandrous perennial clonal herb, Aconitum kusnezoffii, over four consecutive growing seasons by examining more than 39 000 flowers. We also conducted controlled experiments to test the effects of resource and pollen limitation on the female reproductive success of lateral inflorescences. We found that some male functions were positively correlated with flowering phenology, whereas female reproductive success was negatively correlated with flowering phenology and inflorescence position. Lateral inflorescences invested more in male function than terminal inflorescences and therefore yielded fewer and smaller seeds. Resource limitation may serve as the key mechanism underlying this differentiated pattern. Decreased female reproductive success was consistently observed at the flower and inflorescence levels as flowering occurred later in the growth season. Late-blooming lateral inflorescences specialized in the male function, and their female reproductive success was constrained by early-blooming terminal inflorescences. This might be the first attempt to systematically demonstrate sex allocation strategy differentiation in a protandrous plant species at the inflorescence level. In addition, our study provides empirical evidence of dichogamy selecting for specialized sex allocation strategies among inflorescences.

关 键 词：female reproductive success flowering phenology inflorescence architecture pollen limitation resource limitation sex allocation 

分 类 号：Q94[生物学—植物学]