Transcriptomic EST-SSR primer development and genetic diversity analysis of Picria felterrae / 中草药

ABSTRACT

Objective To explore genetic diversity of and genetic relationships among 18 Picria felterrae populations to provide references for the resource assessment and utilization. Methods The genetic diversity of 18 P. felterrae populations were analyzed using the EST-SSR primer development technology and SSR molecular markers, and cluster analysis was performed based on genetic distances to determine the relationships among those populations. Results A total of 48 pairs of polymorphic primers were selected from 100 pairs of EST-SSR markers, of which 20 pairs were randomly selected and used for amplification of 18 populations. A total of 71 alleles were amplified, 3.55 alleles per primer. Among the primers, the percentage of polymorphic loci (P) varied from 0 to 40.7%, with an average of 19.9%; The polymorphism information content (PIC) varied from 0 to 0.794 1, 0.397 7 on average; The Shannon diversity information index (I) varied from 0 to 1.814 3, with an average of 0.808 4; Obs_Het varied from 0 to 0.442 3, with an average of 0.212 7; And the Exp_Het varied from 0 to 0.826 9, with an average of 0.455 8. For the 18 populations, the Inbreeding Coefficient (Fis) varied from -0.095 3 to 0.663 9, with an average of 0.159 2; The inbreeding coefficient of subgroups (Fit) varied from 0.062 6 to 0.858 7, with an average of 0.537 2; The genetic differentiation coefficient (Fst) varied from 0 to 0.686, with an average of 0.449 6; The gene flow (Nm) varied from 0.114 4 to 0.759 4, with an average of 0.306 1. For the 18 samples tested, the gene diversity index (Nei) varied from 0 to 0.401 6, the I varied from 0 to 0.620 9, Wuzhou Guangxi having the maximum value and Longtan Yunnan the minimum value. Menglong and Jingha, two towns in Yunnan, had the shortest genetic distance (0.031 9), whereas Longzhou Guangxi and Menghai Yunnan had the maximum genetic distance (0.963 8). The 18 populations could be divided into four groups at the location where genetic distance was 0.321 3. The three populations in Guangxi belonged to the same group, populations from Menglong, Menglun and Mengzhe of Yunnan belonged in the same group, populations from Mengsong Yunnan became an independent group, and the rest belonged in the fourth group. Conclusion The genetic differentiation levels of 18 populations were not consistent, and the heterogeneity difference was significant. The gene flow among populations was small, which indicated that the population gene exchange was low. A certain inbreeding rate exists among the populations. The relationship among populations was influenced by geographical isolation and environmental factors. Key words