广东常规稻主栽品种品质性状多样性演变分析

 为了解优质育种对品质性状多样性的影响,选取50份不同时期水稻品种来分析其品质性状多样性，并通过对品质性状进行聚类分析和主成分分析（PCA）来了解不同时期品种间的遗传关系。结果表明，1980年以前少数品质性状趋向优质，1980 至1994年期间大部分性状趋向优质，而1994至2008年全部性状都趋向优质。品质性状多样性一直处于下降状态，1994至2008年下降最剧烈。此外，随着时间推移，现代品种与地方品种的遗传差异在扩大。因此，在追求优质的同时，应注重保持水稻品种品质性状多样性和地方稻种资源的利用。

Temporal Change in Diversity of Grain Quality Traits in Major Conventional Rice Varieties in Guangdong Province, China

In order to understand the impact of quality breeding on the diversity of grain quality traits, 50 rice varieties bred at different stages were selected and cluster analysis and principal component analysis (PCA) were conducted to analyze the diversity of grain qualities and their genetic. The results showed that, only a few traits of grain quality (TGPs) were improved among the varieties bred before 1980. For those bred from 1980 to 1994, most of the TGPs were improved, and for those bred from 1994 to 2008, all the TGPs inclined to be good. However, the diversity of grain quality traits followed a trend of decline from early 1950s to 2008, especially during 1994   to 2008. Besides, the difference in genetic background between modern varieties and landraces had been widening over time. Thus, importance should be attached to maintainance of the diversity of quality traits  and the utilization of landraces while pursuing good grain quality.