论文部分内容阅读
本文研究利用北方春小麦区35份品种(系)为材料,通过两年、两地及不同试验处理,研究了春小麦10个数量性状的遗传距离及聚类分析在不同试验处理中的变化。结果表明:遗传距离D~2值是反映品种在一定条件下数量性状综合指标之间的差异;D~2值在不同年份、地点、试验处理中有明显的变化,并无一定的规律性;聚类结果是品种表型聚类;不同处理的聚类结果不一致;D~2值和聚类结果与品种的亲缘关系、地理来源无必然的联系;当不同的试验处理水平所造成的小生态环境相近时,两处理D~2值间存在着显著的正相关,否则,不存在相关关系。在一定生态环境条件下测得的D~2值,只有在与其相近的环境条件下才具有指导意义。此外,依据遗传距离D~2值指导选配亲本具有一定的局限性;1.类间品种杂交可能导致品种近亲繁殖;2.类内品种不杂交会遗漏掉有益杂交组合。
In this paper, 35 varieties (lines) of spring wheat in northern China were used as materials to study the genetic distance of 10 quantitative traits and the changes of cluster analysis in different treatments by two years, two places and different treatments. The results showed that: the genetic distance D ~ 2 value reflects the difference between the comprehensive index of quantitative traits under certain conditions; D ~ 2 values have obvious changes in different years, locations and experimental treatments, and there is no certain regularity; The result of clustering is the phenotypic clustering of varieties; the results of clustering of different treatments are inconsistent; the genetic relationship between the D ~ 2 value and clustering results is not necessarily related to the varieties; when the different experimental treatments result in the niche When the environment is similar, there is a significant positive correlation between D ~ 2 values of the two treatments, otherwise, there is no correlation. The value of D ~ 2 measured under certain ecological environment conditions is of guiding significance only under the similar environmental conditions. In addition, the selection of parents based on the genetic distance D ~ 2 has certain limitations; 1) Inter-species hybridization may lead to species inbreeding; 2) Hybrids of the same species will miss the beneficial hybrid combinations.