Phenotypic diversity of Sinopodophyllum hexandrum from different populations in Nyingchi, Tibet

ObjectiveThe present experiment analyzed phenotypic diversity of Sinopodophyllum hexandrum from dif-ferent populations in Nyingchi, Tibet, in order to provide reference for germplasm resource identification, protection and utilization. MethodTwelve phenotypic traits of S. hexandrum from four different populations(DWZ,DJC,LZQ and NYG) in Nyingchi were measured, then diversity indexes were calculated, and mathematical statistical analysis was conducted for average values of those 12 trait indexes. ResultDiversity of leaves, stems, fruits, seeds of S. hexandrum from 4 popula-tions were high, and Shannon-Wiener diversity index was 0.16-1.76. The rank of the diversity indexes were as follows: leaf transverse diameter>leaf longitudinal diameter>leaf transverse diameter/leaf longitudinal diameter>fruit transverse diameter>fruit longitudinal diameter >stem colour >seed number >fruit transverse diameter/fruit longitudinal diameter >1000 -seed weight>leaf indumentum=leaf incision>leaf crack depth. The variation of leaf area was large, followed by fruit size and seed characteristics, variation of leaf indumentum and leaf incision was relatively stable. Rank of genetic diversity of different populations was as follows: DJC=LZQ>NYG>DWZ. Principal component analysis results showed that: eigenvalue of the first principal component was 6.799 with contribution rate of 56.662%,which was mainly determined by fruit transverse diame-ter/fruit longitudinal diameter, fruit transverse diameter, stem color, leaf crack depth, leaf transverse diameter and leaf longitudinal diameter. Eigenvalue of the second principal component was 3.024 with contribution rate of 25.200%, which was mainly determined by fruit transverse diameter, seed number, leaf transverse diameter/leaf longitudinal diameter. Ac-cording to correlation analysis, there were significant correlation(P<0.05) and extremely significant correlation(P<0.01) among partial traits of S. hexandrum(between leaf transverse diameter and leaf longitudinal diameter, leaf indumentum and leaf incision, fruit transverse diameter/fruit longitudinal diameter and stem colour). Cluster analysis results showed that, the four populations can be divided into two groups at euclidean distance 9, where DJC population first separated from the four provenances.Hence it belonged to the first category and the other three populations grouped into the second category. At euclidean distance 2, the second category was divided into two subgroups: LZQ population was in one category, DWZ and NYG populations were in the other category. ConclusionThe phenotypic diversity of S. hexandrum from different populations in Nyingchi is high, and the variation of phenotypic traits is discontinuous.