筛选对脱叶剂敏感的南疆陆地棉种质资源

【目的】研究南疆90个陆地棉种质资源喷施脱叶剂后脱叶和吐絮情况,筛选出对脱叶剂敏感的种质资源,为筛选和培育脱叶剂敏感品种提供参考。【方法】对南疆90份陆地棉种质资源喷施脱叶效果较好的脱叶剂脱吐隆(复配乙烯利),分别调查喷施脱叶剂后,不同时间不同类型棉花叶片脱落和棉铃吐絮情况。【结果】不同棉花种质资源的脱叶率在第4 d及第7 d有显著差异,最终脱叶率高达95%以上的品种有新陆中2号、新陆中5号、合信27等10个品种;不同品种间药后吐絮率不同;不同类型叶片脱叶率及脱叶效果不同;根据脱叶效果进行聚类分析,将90份种质资源分为4类,其中第Ⅱ类品种对脱叶剂最敏感。【结论】喷施脱叶剂后不同品种脱叶率和吐絮率有所不同,第4~7 d的脱叶率可以作为南疆陆地棉品种对脱叶剂敏感性的评价指标;果枝叶的脱叶效果最好,叶枝叶次之,主茎叶最差;第Ⅱ类是脱叶剂敏感种质。

Screening of Upland Cotton Germplasm Resources Which Are Sensitive to Defoliant in Southern Xinjiang

【Objective】 The defoliation and boll opening rate of cotton germplasm resources in southern Xinjiang were studied after spraying defoliant in order to screen out the germplasm which might be sensitive to defoliants and provide reference for selecting and breeding sensitive cultivars to defoliant. 【Method】The defoliant (thidiazuron) with good defoliation effect was used (combined with ethephon) in the project to separately investigate the number of leaves and boll opening rate at different times after spraying defoliant. 【Result】 The defoliation rate of different cotton varieties was significantly different on the 4th and 7th days. The varieties with defoliation rate more than 95% included Xinluzhong 2, Xinluzhong 5, and Hexin 27, etc; the post-drug boll opening rate varied among different varieties; the defoliation rate and defoliation effect of different types of leaves were different; 90 germplasm resources were classified into 4 categories by cluster analysis, and the second category was sensitive to defoliants. 【Conclusion】The defoliation rate and the boll opening rate of different varieties were different, and the defoliation rate at the 4th to 7th day could be used as the index to evaluate the sensitivity of upland cotton varieties to defoliant in southern Xinjiang. As to the effect of spraying defoliant, the fruit branch leaf was the best, followed by the foliage leaf, the main stem leaf was the worst. The cluster analysis showed that the second class was the most sensitive germplasm to defoliant.