早籼良种主要性状分析和高产育种探索

ANALYSIS ON THE MAIN TRAITS AND DISCUSSION ON HIGH-YIEID BREEDING TO EARLYINDICA RICE VARIETIES

本文用通径分析、主成分分析和聚类分析方法对近年全国育成的16个早籼良种主要性状的分析结果表明:产量和产量性状间存在极复杂的相关关系,以穗长、千粒重、穗着粒数和有效穗对产量的直接作用较大;按累积贡献率≥85％,确定了粒数因子、穗数因子、粒重因子和结实率因子4个主成分,以粒数因子的贡献率最大,为38.06％。16个早籼良种按遗传距离可分为3类。增大穗子和增加粒重是早籼品种进一步高产的主要育种途径之一。

The main traits of 16 early rice varieties were studied with path analysis, the principle component analysis and the cluster analysis. The results were as follows, there were more complicated correlations between yield and yield components. The length of panicle, 1000-grain weight,grains per panicle and panicles per hill had greater influence on grain yields; according to criteria of the cumulative pet. of variable ≥85%, there were four principle components ;grains per panicle, panicles per hill, 1000-grain weight and seed setting percentage. Grains per panicle had larger contribution. 16 varieties were divided into three groups according to the genetic distance in cluster analysis ; one of the main path to enhance yield of early rice varieties was to increase grains per panicle and 1000-grain weight.