关键词: 水稻育种, 理想株型, 比叶重, 叶绿素含量

Abstract: Rice breeding for ideal plant morphology is in effect the breeding for high light utilization. Thus, its theoretical basis is inevitably to both the genetic and physiological aspects of knowledge. The varietal difference in specific leaf weight and chlorophyll content, which are regarded as the essential elements of leaf quality, is quite significant, especially the former seems to be more stable than the latter and more consistent under different conditions. Besides, there is significant positive correlation between specific leaf weight and chlorophyll content, each of them is positively correlated with leaf nitrogen content to be highly significant, and the latter in turn is positively correlated with net photosynthetic rate to be highly significant too. Leaf area, specific leaf weight and chlorophyll content are highly related to well-filled grains per panicle and to the average panicle weight, with the order leaf area > specific leaf weight > chlorophyll content in the degree of relationship. Among these, the direct effect of specific leaf weight in relation to panicle weight is comparatively more marked, and that of chlorophyll content may become more and more important with respect to dry matter production in the later stage of growth. Therefore, in rice breeding for ideal plant morphology, in particular for maximal sunlight utilization, while leaf area is to be firstly considered, attention should also be paid to specific leaf weight and chlorophyll content. Since estimation of leaf area, specific leaf weight and chlorophyll content is rather easy to handle, which can be done either by eye (for leaf area and chlorophyll content) or by hand touching, this method is of practical importance in screening so large progeny as in rice breeding.

Key words: rice breeding, ideal plant morphology, specific leaf weight, chlorophyll content, yield component