The Genetic Diversity of Bletilla spp. Based on SLAF-seq and Oligo-FISH

Bletilla spp. Rchb. F. is a traditional Chinese medicinal material. In this study, Bletilla striata (Thunb. ex A. Murray) Rchb F, Bletilla formosana (Hayata) Schltr, and Bletilla ochracea Schltr were collected to analyze the genetic diversity of 16 materials using specific site-amplified fragment sequencing (SLAF-seq) and fluorescence in situ hybridization (FISH). The results showed that the phylogenetic tree of the single-nucleotide polymorphism (SNP) data rendering system was correlated with the shape and geographical distribution of the material. The results of the population structural analysis showed that all the materials containing yellow labellum came from the same ancestor. The results of the principal component analysis were able to preliminarily judge the genetic distance and provided a reference for the selection of hybrid parents. The FISH analysis showed that the chromosomes of B. striata were 2n = 32 and the chromosomes of the B. striata (safflower) mutant were 2n = 34 and the chromosomes of B. ochracea and B. formosana were 2n = 34-36. The (AG₃T₃)₃ non-terminal signal was different from the 5S rDNA signal. These results revealed that the 16 materials had rich genetic diversity, which can provide molecular and cytogenetic data for the study of the genus and its relatives and serve as a reference for the breeding of new genus varieties and improve breeding efficiency and cost.