宁夏水稻地方品种与自育品种表型性状遗传多样性分析

Genetic Diversity of Phenotypic Traits of Rice Landraces and Self-bred Varieties in Ningxia

为了解宁夏水稻地方品种与自育品种的遗传多样性水平,采用模糊数学的方法,对145份宁夏水稻地方品种与自育品种的表型性状进行遗传变异性和多样性研究。结果表明:20个数量性状中有19个性状的遗传变异达到极显著水平,变异系数为1.13%~28.74%。株高、每穗总粒数,每穗实粒数、二次枝梗数、单株籽粒总质量的变异幅度较大,方差和标准差值也较大,其离散程度相对较大;4个质量性状的遗传多样性指数变幅为0.55~1.19,平均为0.97;20个数量性状的遗传多样性指数变幅为0.91~2.11,平均为1.62;以方差分析差异极显著的19个性状进行主成分分析,从19个特征根中选取8个较大的特征根及相应的特征向量,包括每穗总粒数、单株籽粒总质量、单株穗数、单株分蘖数、籽粒长宽比、一次枝梗数、株高、结实率为主要因子,累积贡献率为88%。采用UPGMA法对供试材料进行聚类分析,在相似系数为0.75处可将不同种质资源材料划分为5类,其中第Ⅰ类、第Ⅱ类各自只包含1个品种;第Ⅲ类中都为中高秆、穗子较长、着粒密度较高的高产品种;第Ⅳ类为近年育成的一些品种(系),占总数的64%,属于优质常规粳稻,表现为中高秆、散穗、结实率相对较高;第Ⅴ类为地方品种和早期育成品种,地方品种与自育品种有较大的遗传差异。可见,宁夏水稻自育品种的遗传多样性指数明显高于地方品种,地方品种与自育品种间有一定的遗传差异,在育种中可挖掘地方品种中的有利基因。

In order to study genetic diversity of rice landraces and self-bred varieties in Ningxia, the genetic variability, genetic diversity of 145 rice landraces and self-bred varieties in Ningxia were analyzed with fuzzy mathematic analysis.The results showed that the genetic variation of 19 quantitative traits in total 20 quantitative traits was significantly different, and the range of variation coefficient in 20 quantitative traits was from 1.13% to 28.74%.The plant height, grain number per panicle, filled grain number per panicle, number of secondary branches, and total grains mass per plant of 145 rice varieties showed bigger variation range and higher variance.The genetic diversity indices of four quality traits ranged from 0.55 to 1.19, with the average genetic diversity index of 0.97, while the genetic diversity indexes of 20 quantitative traits ranged from 0.91 to 2.11, with the average genetic diversity index of 1.62.The principal components analysis was conducted with nineteen traits with significant difference, and eight principle factors were chosen with the cumulative rate of 88%.The cluster analysis results showed that all the 145 rice varieties can be divided into five groups when similarity coefficient was 0.75, the group Ⅰand the group Ⅱcontained only one variety each, but the group Ⅲ contained some high-yield varieties that had plant height, long spike and high grain density, and group Ⅳ contained some varieties bred in recent years with the traits of high-quality and conventional rice varieties with middle to plant height, loose panicle and high seed setting rate, which account for 64% of total 145 varieties.Group Ⅴ contained the most of landraces and early stage bred varieties, with the traits of a greater genetic difference between landraces and self-bred varieties.Above all, the genetic diversity indexes of self-bred rice varieties were higher than that of landrace significantly, and there were some genetic differences between landraces and self-bred varieties, so the favorable genes of landraces can be applied in rice breeding in Ningxia.