嫁接对棉花抗黄萎病的影响

 【目的】探讨不同嫁接类型对棉花黄萎病抗性的影响，研究棉花黄萎病发病机理和抗病机制，为深入分析棉花抗病机理、培育抗黄萎病棉花品种提供理论基础。【方法】选取6个不同黄萎病抗性的海岛棉和陆地棉品种，每个品种均设自身嫁接和相互嫁接2种嫁接方式和不嫁接的直播对照；田间试验鉴定比较直播材料与自身嫁接材料、相互嫁接材料的发病程度。【结果】自身嫁接材料与直播材料发病情况相同；以海岛棉抗病品种做接穗的嫁接组合的病情指数与发病率显著低于陆地棉抗病品种为接穗的嫁接组合；以陆地棉抗病品种为砧木的病情指数与发病率显著低于海岛棉抗病品种为砧木的组合。【结论】嫁接操作本身对棉花黄萎病的抗性没有显著影响。海岛棉和陆地棉的抗黄萎病机制不同，海岛棉抗病品种的关键抗病部位为茎部；而陆地棉抗病品种的关键抗病部位为根部。

Study on Cotton Resistance to Verticillium Wilt by Grafting

【Objective】The objective of this study is to investigate the influence of grafting on cotton resistance to Verticillium wilt and to clarify the resistance mechanism of cultivated cotton species, which should be benefit to further understand the disease resistant mechanism and to breed new cotton resistant varieties. 【Method】 Six cotton varieties with different resistances to Verticillium wilt were selected based on previous research. Each variety was self and mutual grafted, and the direct sowing cotton was used as control. The disease occurrence and severity of direct sowing cotton varieties, self-grafted cotton lines and mutual grafting cotton lines were identified and compared in field trials. 【Result】 The disease index and incidence of direct sowing cotton varieties and their self-grafted cotton lines were not significantly different. The average disease index of materials with resistant island cotton varieties as scions were significantly lower than that of materials with resistant upland cotton varieties as scions, however, the average disease index of materials with upland cotton resistant varieties as rootstocks were significantly lower than that of materials with island cotton resistant varieties as rootstocks. And the tendency of disease incidence was the same as disease index.【Conclusion】The grafting operation doesn’t make any significant influence on cotton resistance to Verticillium wilt. The resistance mechanism of the island cotton species is different to that of upland cotton species. The critical organism resistant to Verticillium wilt should be stem in the case of resistant island cotton varieties, but in the case of resistant upland cotton varieties the critical organism resistant to Verticillium wilt should be root.