棉花枯萎病菌(Fusarium oxysporum f.sp.Vasinfectum(ATK)Sndyder & Hansln的抑菌土初步研究

STUDY ON THE SOILS SUPPRESSIVE TO Fusarium Oxysponum f. sp. Vasinfectum

1987～1988年在河南新乡用相同接菌量种植感病品种,对棉花抗枯萎病品种86—1连作10年以上田块土样进行盆栽和田间小区试验。结果表明.枯萎病平均病指分别为29.4和4.4,与对照果园土比较抑菌效果分别为39.9％和85.8％。上述田块中86—1棉株根围5cm内土样,盆栽枯萎病平均病指19.5,抑菌效果60.5％。连作10年以上枯萎病圃土样,病指分别为27.2和6.8,抑菌效果为43.9％和76.2％。1990～1991年在辽宁省经作所试验结果,连作10年以上枯萎病圃田间抑菌效果56.2％,连作5年病圃抑菌效果17.6％。上述结果证明,枯萎病圃衰退的主要原因是棉花枯萎病菌抑菌土的产生和存在。土样内枯萎菌菌量测定结果表明,3个抑菌土土样内菌量比果园导菌土减少48.6％～59.2％。抑菌土经高压灭菌后抑菌效果完全消失,初步证明抑菌因子可能以生物因子为主。

Cotton Fusarium wilt pathogen suppressive soil was found by pot and field plot experiment during 1987～1991. Soils which collected from diseased field by successively planting Fusarium wilt resistant cultivar 86—1 more than 10 years and from an orchard or vegetable field were inoculated with Fusarium oxysporium f. sp. vasinfectum. Then susceptible variety was planted in it. Average disease index of cotton in pot and field plot were 19.4 and 4.4, respectively effect of suppression were 39.9% and 85.8%, respectively suppressive effect of the rhizosphere soil of 86—1 within 5cm was 60.5%, the disease index was 19.5. The disease index were 27.2 and 6.8, suppressive effect were 43.9% and 76.2% respectively in an artificial inoculated field used for resistance breeding more than 10 years. colony of Fusarium oxysporium f. sp. vasinfectum in both pot and field plot soil test were decreased 48.6%～59.2% than that in orchard soil or vegetable field soils. In another field experiment at Liaoyang in 1990～1991, the average effect of suppression were 56.2% and 17.6%, respectively in fields used for Fusarium wilt nursery 10 years and 5 years. The result indicated that there are suppresive soils in Fusarium wilt infected cotton fields. Suppression effect will be lost completely by sterization.