宁夏水稻主要农艺性状的主成分及聚类分析

Principal Component and Cluster Analysis of Main Agronomic Characters of Rice in NingXia

水稻育成品种遗传基础的宽窄及品种间遗传距离的大小是品种能否在当地有效推广种植的关键因素,同时也是水稻杂交育种中选配亲本的基础。多元统计分析方法常用来测定品种间的遗传差异,了解亲本间的遗传距离。试验以宁夏引黄灌区历年主栽或新选育的水稻品种为材料,分别考查了20个水稻品种的12个主要农艺性状,对均达显著和极显著差异的12个性状进行了主成分分析,由主成分分析中提取的公因子进行聚类分析,并计算各类群主要性状的平均值,得出各类群品种的分类特点。结果表明:20个水稻品种的12个主要农艺性状可归结为5个主成分,经聚类分析,可将20个水稻品种选定合适的阈值后划分为4个类群,表现出遗传距离较近,遗传基础狭窄的特点,并且宁夏水稻品种主要集中在第4类群。因此,在确定水稻育种杂交亲本选配时,要综合考虑主成分互补,且要在类群间进行,并结合米质的选择,则有望选育出农艺性状优良、优质、高产的新品种。但改良品种个别性状时,亲本之一符合育种目标,另一亲本也可选用遗传距离不大的品种。

The key factor of the rice varieties that whether could be cultivated in native region was the rice varieties with broad genetic basis and far genetic distance, and it was also the basis of choice parent in crossing breeding. The method of multiple factor statistic analysis was often used to examine the genetic difference between varieties and understand the genetic distance between parents. The materials in this experiment were the varieties of main cultivated or new brought in yellow river irrigation areas of Ningxia in many years. The twelve main agronomic characters of twenty rice varieties were investigated, and twelve main characters which showed notability difference were used to principal components analysis. Common factors were separated from principal component and used to cluster analysis. The average number of main characters in every class was calculated, and every class variety characteristic was obtained. The result showed that the twelve main characters of twenty rice varieties could be classified into five principal components. Through cluster analysis, twenty rice varieties could be classified into four class after choose proper threshold according to genetic distance, showing near genetic distance and narrow genetic basis in twenty rice varieties, and most varieties of Ningxia was collected mainly in the fourth class. Therefore, when choosing the parents in intercross breeding in rice, the parents should be complemented to each other in the principal component, and another parent was selected in other class, and combining with grain quality of rice, the new variety with excellent agronomic characters and grain quality and high product was brought up. When improved one or two characters, one parent accord with the demands of breeding object,another parent may be chosen in other varieties not so far for genetic distance in each other.