Microsatellite marker-based analysis of the genetic diversity and population structure of three Arnebiae Radix in western China

Arnebiae Radix is an important medicinal and perennial herb found in Western China, particularly in the Xinjiang region. However, the assessment, utilization and conservation of Arnebiae Radix resources are still unexplored. In this study, we evaluated the genetic diversity of three Arnebiae Radix populations across 47 regions (Ae = 16, Ag = 16, Ad = 15) in Xinjiang, China, using inter-simple sequence repeat (ISSR) molecular markers. In total, 48 alleles were amplified by six pairs of primers screened with ISSR markers. The average number of effective alleles (Ne) was 1.5770. The percentage of interspecific genetic polymorphisms in A. guttata (Ag = 89.58 %) was greater than that in A. euchroma. and A. decumbens (Ae = Ad = 87.50 %). Intraspecific genetic polymorphisms, Bo Le (BL) population of A. euchroma exhibited the highest percentage of polymorphic bands (PPB% = 58.33 %, Na = 1.313, Ne = 1.467, I = 0.0.366, H = 0.255), which indicated high genetic diversity. In contrast, the Tuo Li (TL) population of A. guttata had the lowest values for these parameters (PPB% = 0.00 %, Na = 0.313, Ne = 1,000, I = 0.000, H = 0.000). The Arnebiae Radix germplasms were classified into two major groups (I and II) based on UPGMA cluster analysis (Fig. 8a) and principal coordinate analysis (PCOA). In addition, A. decumbens is placed in a separate category due to its high differentiation coefficient. The AMOVA and genetic differentiation coefficient results indicated that the genetic variation in Arnebiae Radix was predominantly due to intrapopulation differences (78 %). Additionally, the gene flow index (Nm) between populations was 2.4128, which further indicated that the genetic diversity of Arnebiae Radix was greater at the intrapopulation level. The destruction of the ecological environment leads to the continuous reduction and degradation of the genetic diversity of Arnebiae Radix germplasm resources. In this study, we used ISSR molecular markers to analyze the genetic diversity and relatedness of Arnebiae Radix, which revealed the genetic relationship of Arnebiae Radix germplasm resources at the molecular level and provided a scientific basis for future research on selecting and breeding good varieties, evaluating the quality of Arnebiae Radix, and conserving and utilizing its resources.