滇龙胆野生种质资源的表型多样性与综合评价

Phenotypic Diversity Analysis and Comprehensive Evaluation of Wild Germplasm Resources of Gentiana rigescens

探讨滇龙胆(Gentiana rigescens Franch.)表型多样性并建立优良种源综合评价方法。采集分布于云南的477株个体19个性状数据,结合遗传多样性指数、主成分分析、隶属函数、偏最小二乘等方法,开展滇龙胆种质资源评价。结果显示477株滇龙胆根、茎、叶性状遗传多样性指数范围:1.59~2.06;各性状中根粗(H’=2.00)、茎粗(H’=2.00)、根质比(H’=2.02)和根含水量(H’=2.06)遗传多样性指数较高,地上部分干重遗传多样性指数最低(H’=1.59)。不同地理来源的滇龙胆植株性状差异较大(P<0.05),分布于滇南的滇龙胆根部产量性状数值显著高于其他分布区的植株(P<0.05)。综合得分D值计算显示,477株滇龙胆D值变化范围:0.50~2.45,采自滇西、滇西北(D=1.17±0.03)及滇南(D=1.19±0.37)的植株综合评分较高,滇中(D=1.00±0.30)和滇东南(D=1.00±0.32)样品综合评分较低;云县居群植株综合评分高(D=1.24±0.14),且居群内个体间性状差异小(CV=11.02%),属最优种源。偏最小二乘-回归分析(PLS-R)与偏最小二乘-判别分析(PLS-DA)发现,根鲜重、根干重、全草干重、分枝数、根数、地上部分干重、茎粗及叶长是区分优劣种源的关键性状(VIP>1.00);土壤属性、生长期降水、最干季平均气温等环境因子则与滇龙胆高产性状的形成紧密相关(VIP>1.00);土壤沙土含量过高、粘土含量过低,干旱高温可能促使根鲜重、干重和根数数值呈降低趋势;4月、5月及11月降水增加则对根部性状提高有积极作用。

The purpose of this study was to explore the phenotypic diversity of Gentiana rigescens Franch.ex Hemsl and establish a comprehensive evaluation method for excellent provenances of the species. The phenotypic datasets of 19 traits in 477 individuals from Yunnan province were collected. The Shannon-Wiener diversity index, principal component analysis, membership function, and partial least square were used to evaluate the provenances of G. rigescens Franch. The value of Shannon-Wiener diversity index(H’)of root, stem, and leaf traits of 477 individuals ranged from 1.59 to 2.06. At the several traits such as root diameter(H’=2.00), stem diameter(H’=2.00), root/biomass ratio(H’=2.02) and root water content(H’=2.06), the highest H’ values were observed. The dry weight of aerial part of plants showed the lowest H’ value(H’=1.59). The plant traits of G. rigescens Franch. which was from different geographical regions were significant differences(P<0.05). Notably, the root yield traits value of G. rigescens Franch. from southern Yunnan was significantly higher than those in other distribution areas(P<0.05). Based on the comprehensive evaluation value(D value)of phenotypes, the D value of 477 G. rigescens Franch. ranged from 0.50 to 2.45. The individuals collected from western and northwestern Yunnan(D=1.17±0.03)and southern Yunnan(D=1.19±0.37)had higher comprehensive evaluation value. Meanwhile, the D value of the individuals collected from central Yunnan(D=1.00±0.30)and southeastern Yunnan(D=1.00±0.32) were lower. The Yunxian population had the highest comprehensive evaluation value of plant(D=1.24±0.14), and small differences in traits among individuals within the population(CV=11.02%). It suggested that individuals of Yunxian population were excellent provenances. Through the analysis of PLS-R and PLS-DA, it was found that root fresh weight, root dry weight, dry weight of plant, branch number, fiber number, dry weight of aerial part, stem diameter and leaf length(VIP>1.00)were the key traits for the discrimination of good and bad provenances. And the environmental factors such as soil properties, precipitation during plant growing period and average temperature in the driest season were closely related to the high yield traits of G. rigescens Franch.(VIP>1.00). The higher content of sandy and the lower content of clay in soil, drought and high temperature might lead to reduce of root fresh weight, dry weight and root number. The higher precipitation in April, May and November was observed with positive effects at root-relates traits.