Genetic structure of a narrowly distributed species Chimonobambusa tumidissinoda in the Yunnan-Guizhou Plateau, and its implications for conservation

Abstract

Chimonobambusa tumidissinoda is a narrowly distributed and endangered bamboo species, which is endemic to the Yunnan-Guizhou Plateau and possesses significant ecological and economic value, particularly due to its delectable shoots. In this study, we employed the restriction site-associated DNA sequencing (RAD-seq) method to elucidate the population structure, genetic diversity, and demographic history of C. tumidissinoda across its entire distribution range. Unlike the genetic pattern revealed previously, three distinct genetic groups within the C. tumidissinoda samples were consistently discriminated based on multiple analyses, and low levels of genetic diversity (HO = 0.085, HE = 0.115, π = 0.116) were found. Furthermore, moderate genetic differentiation (FST = 0.070 - 0.095; PhiPT = 0.129 - 0.156) was detected among these groups with Mantel tests suggesting that isolation by distance (IBD) could potentially drive population genetic differentiation in this species. Moreover, demographic analyses incicated that C. tumidissinoda likely experienced a bottleneck event since the Pliocene, which may be attributed to drier and colder winters in Yunnan resulting from intensified Asian monsoon activity. Based on these findings, we suggest that the endangered status of C. tumidissinoda has been underestimated. Conservation measures should be implemented both in situ and ex situ to enhance its adaptability towards future climate fluctuations. Additionally, seed collection for germplasm storage is recommended.

Keywords

• Chimonobambusa tumidissinoda
• RAD-seq
• Genetic diversity
• Demographic history
• Conservation