基于SSR分子标记的5个黄花补血草居群花型变异及其遗传效应

In heterostylous plants, the floral morph composition and frequency of populations are a consequence of mating events over generations.Homostylywith anthers and stigmas at the same level within a flower is a floral morph that frequently appears in the evolution of heterostyly and is often accompanied by breakdown of the heteromorphic incompatibility system and the decline of genetic diversity. To explore the formation of the H-morph and its effects on the population, we studied five Limonium aureum populations exhibiting a widely distributed floral morph (H-morph), similar tohomostyly,in the southern margin of Tarim Basin. The floral morph composition and heterostylous syndrome were investigated by field observations and hand pollination experiments. Meanwhile, the genetic diversity and genetic structure were studied using SSR molecular markers. The results showed the following: (1) The Atushi (ATS) population consisted only of the H-morph, while the remaining four populations were composed of the long- and short-styled morph, and H-morph. All populations had a moderate level of genetic diversity, dimorphism of stigma-pollen morphology, and a strict heteromorphic incompatibility system, revealing that the floral morphs with different pollen ornamentation and stigma papilla cell morphology were compatible. (2) Genetic structure analysis, principal coordinate analysis, and phylogenetic analysis showed that the ATS population had emerged earlier and was independent of the other four populations phylogenetically, with a significant correlation between genetic distance and geographic distance. (3) The H-morphs of the two types of populations may be at different stages of the evolution of heterostyly. The self-incompatibility of the H-morph and the heteromorphic incompatibility system of the population maintained the populations geneticdiversity