建国以来我国长江流域棉区棉花品种的遗传改良Ⅰ.产量及产量组分性状的改良

本文是我国长江流域棉区棉花品种遗传改良研究的系列报道之一, 目的在于探讨建国以来我国长江棉区棉花品种在产量和产量组分性状(株铃数、铃重和衣分)上遗传改良的成效. 对不同历史时期11个代表性品种两年7点的试验资料和30多年区域试验历史资料的研究表明, 建国以来, 我国长江棉区棉花品种的产量性状改良成效显著, 品种的产

Genetic Improvement of Cotton Varieties in the Yangtse Valley in China since 1950sⅠ.Improvement on Yield and Yield Components

This paper is one of a series of reports on the genetic improvement of cotton varieties in the Yangtse valley in China since 1950s, the purpose of which is to study the genetic improvements on yield and yield components (bolls per plant, boll size and lint percentage). Experimental data of 11 representative varieties at 7 locations in two years and historical data of regional cotton trials in the Yangtse valley in the last 30 years were analyzed. The results indicated that the effect of genetic improvement of cotton varieties in the Yangtse valley was significant, the average increase of the lint yield in the last 50 years is 6.50 kg/hm 2 per year; the narrow-sense contributive ratio of genetic improvement is 36.9%( 4.2%~52.1%); the broad-sense contributive ratio of genetic improvement is 62.0%. 45.0% and 20.4% of the increase of the current varieties were due to genotype and genotype-environmental interaction respectively. Compared to old varieties, lint yield of the current varieties increased by 24.3%, number of bolls by 3.49 per plant, lint percentage by 2.80% and boll size changed non-significantly. The yield increase of the current varieties was mainly caused by the improvements of number of bolls per plant and lint percentage. The relative effects number of bolls per plant and boll size and lint percentage on lint yield varied at different stages, which reflected the change of breeding strategy and selection emphasis. Selection for big bolls and high lint percentage would be a valid strategy for cotton lint yield breeding in the Yangtse valley .