中国南方和越南北方为世界喀斯特地貌分布面积最大的地区，为物种的形成和分化提供了极为优越和独特的场所，溶洞是其中最具特色的小生境之一。目前，围绕洞穴的进化和适应研究多集中于动物方面，而植物方面则较少。洞穴动物的研究揭示在中国南方洞穴内蕴含着许多的隐形种。申请人经过对喀斯特特有植物秋海棠侧膜组的长期研究，发现其中的昌感秋海棠和癞叶秋海棠两个复合群分别生长在海拔800-1800米和200-600米两个不同海拔段，它们都包含着一个广布种和2-3个狭域种，其内部分化与洞穴生境密切相关，是研究洞穴物种形成的理想材料。因此，我们拟选择这两个复合群所有的8个种、34个居群以及约340个个体，运用简化基因组技术（Rad-seq），开展群体基因组学研究，构建它们的进化格局，通过两个复合群的对比研究，探讨洞穴生境对物种形成的作用，验证洞穴植物隐形种存在的真实性，并深入认知洞穴在喀斯特生物多样性保护的意义。

South China and North Vietnam have the largest karst region in the world providing a unique habitat to differentiation and speciation, where karst caves are one of the most specialized microhabitats. At present, cave animals are at the center of evolutionary and adaptive research rather than plants, which revealed that there may be a larger number of crytomorphic species in the caves of South China than previously thought. Based on a long-term study on Begonia sect. Coloecentrum Irmsch. in Begoniaceae, an endemic plant group in the karst regions in China and Vietnam, we found that the Begonia cavaleriei complex and the B. leprosa complex are distributed spatially separated by altitude, at 800-1800 m and 200-600 m respectively in the karst areas. Both complexes include a widespread species and two or three narrow species, whose differentiation is closely associated to caves. The two complexes provide an ideal model for exploring speciation of plants in both karst area and karst caves. Thus, we plan to sample about 340 individuals of all 8 species and about 34 populations of the two complexes. We will carry out population genomic studies using Rad-seq sequencing and explore the evolution patterns of these endemic plants in the karst region. By contrasting the results from the two complexes, we will further be able to explore the influence of cave habitat on speciation, and to establish whether there are also numerous crytomorphic species among the plant species in the caves. This study will provide further insights on the significance of karst caves on the accumulation of biodiversity.