西藏林芝不同居群桃儿七表型多样性分析

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

【目的】分析西藏林芝不同居群桃儿七的表型多样性,为桃儿七种质资源鉴定、保护和利用研究提供参考。【方法】对西藏林芝4个不同居群桃儿七(DWZ、DJC、LZQ和NYG)的12个表型性状进行测定,计算其多样性指数,并对12个性状指标的平均值进行数理统计分析。【结果】4个不同居群桃儿七的叶、茎、果实、种子等表型性状多样性较高,Shannon-Wiener多样性指数在0.16~1.76,按其多样性指数排序为叶横径>叶纵径>叶横径/纵径>果横径>果纵径>茎色>种子数>果横径/纵径>种子千粒重>叶被毛=叶裂缺>叶裂深浅;不同居群桃儿七叶片大小变异较大,其次为果实大小和种子特性,叶被毛和叶裂缺变异最小。不同居群桃儿七的遗传多样性水平依次为DJC=LZQ>NYG>DWZ。主成分分析结果显示,第一主成分特征值为6.799,贡献率为56.662%,主要由果横径/果纵径、果横径、茎色、叶裂深浅、叶横径、叶纵径决定;第二主成分的特征值为3.024,贡献率为25.200%,主要由果横径、种子数、叶横径/叶纵径决定。相关性分析发现,桃儿七部分性状(叶横径与叶纵径、叶被毛与叶裂缺、果横径/纵径和茎色间)间表现出显著(P<0.05)或极显著(P<0.01)相关。聚类分析结果显示,4个居群可划分为两大类群,即在欧氏距离9处,DJC居群首先从4个种源中分离出来,归为一类,其余的3个居群归为第二类;在欧氏距离2处,第二类又分为两个亚类,LZQ居群自成一类,DWZ和NYG居群为一类。【结论】西藏林芝不同居群桃儿七具有较高的表型多样性,且表型性状的变异具有间断性。

【Objective】The present experiment analyzed phenotypic diversity of Sinopodophyllum hexandrum from different populations in Nyingchi, Tibet, in order to provide reference for germplasm resource identification, protection and utilization. 【Method】Twelve 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. 【Result】Diversity of leaves, stems, fruits, seeds of S. hexandrum from 4 populations 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 diameter/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. According 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. 【Conclusion】The phenotypic diversity of S. hexandrum from different populations in Nyingchi is high, and the variation of phenotypic traits is discontinuous.