陆地棉根系分泌物对黄萎病菌生长发育的影响

The Effects of Cotton Root Exudates on Growth and Development of Verticillium dahliae

以不同抗黄萎病性的6个陆地棉品种(系)为材料,研究陆地棉根系分泌物对黄萎病菌生长发育的影响。结果表明,感病品种根系分泌物中氨基酸种类和数量显著多于抗病品种。与感病品种相比,抗病品种根系分泌物中缺少天门冬氨酸、苏氨酸、谷氨酸、丙氨酸、异亮氨酸、亮氨酸、苯丙氨酸、赖氨酸和脯氨酸等9种氨基酸,而精氨酸又是抗病品种所特有的。二类品种根系分泌物中糖类物质种类差别不大,但感病品种根系分泌物中的葡萄糖、果糖和蔗糖含量均显著高于抗病品种。研究结果还表明,抗病品种根系分泌物可有效地抑制黄萎病菌孢子的萌发和菌丝的生长,而感病品种根系的分泌物则促进黄萎病菌的生长。

The effects of upland cotton root exudates on the growth and development of Verticillium dahliae were studied, through the compared analysis of the root exudates components between the resistant and susceptive cotton materials, using a pair of resistant and susceptive isogenic lines to Verticillium wilt, Z5629 and Z421, as well as four other upland cotton cultivars with different level of Verticillium wilt resistance. The results showed that the kinds of amino acids in the root exudates of resistant cultivars were much less than that of susceptible ones. Compared with susceptible ones, the root exudates of resistant cultivars were lack of aspartic acid, threonine, glutamic acid, alanine, isoleucine, leucine, phenylalanine, lysine and proline, but they did have arginine that was lack in the susceptive ones on the contrary. The saccharide types in the root exudates had no difference between the susceptive and resistant cultivars, but the concentrations of glucose, fructose and sucrose in the root exudates of susceptible varieties were much higher than those in resistant ones. The experiment of Verticillium dahliae, culture showed that the cotton root exudates from resistant cotton cultivars could restrain the spore germination and mycelium growth of Verticillium dahliae effectively, due to poor nutrition of root exudates from the resistant cotton cultivars mainly. Among the amino acids in the root exudates, the arginine, which was lack in susceptive cotton cultivars, was a special one that could control the growth and development of the Verticillium dahliae. However, the cotton root exudates from susceptive cotton cultivars could improve the growth and development of Verticillium dahliae, among those amino acids in the exudates, the alanine was the most active one in the stimulated function. According to this experiment, it is suggested that the cotton root exudates could be used as a biochemical marker in selection of the cotton materials for Verticilium wilt resistance. Those having lesser kinds and lower concentrations of amino acids and saccharides in the root exudates may be the resistant ones which can be used in cotton breeding program, except for arginine which is the exclusive amino acid without in susceptive cotton root exudates and have the strong restrained effect to the growth and development of the Verticillium dahliae, being a resistant biochemical maker.