棉花烂铃病的发生、品种抗病性及主要病原菌致病力分析

2011~2013年,调查了我国黄河和长江流域6省70县(市)200块棉田和不同栽培模式下棉花烂铃病发生情况,田间试验评价了棉花品种对烂铃病的抗性,采用离体棉铃人工接种方法分析了棉铃烂铃主要病原菌的致病力分化情况。结果表明:(1)所有调查的棉田均有棉花烂铃病发生,其中,棉铃疫病在各地发生最为普遍而且严重,仍属于我国黄河和长江流域棉区的最主要的棉花烂铃病,其病原菌为苎麻疫霉(Phytophthora boehmeriae)。(2)与春棉直播模式相比,3种套种模式均能显著减少棉花烂铃病的发生,其中麦-棉-西瓜12∶2∶1种植模式的防效最好,减少烂铃72.96%。(3)河北、山东和河南3省审定的50个棉花品种对棉花烂铃病的抗性存在显著差异,其中邯7860、邯棉103、锦科178、百棉1号和郑农棉4号5个品种对棉花烂铃病表现了较好的抗性,单株烂铃低于3.0个。(4)苎麻疫霉在棉铃上的致病力存在显著分化。

Cotton boll rot occurrence,analysis of varietal resistance and pathogenicity dif ferentiation of the major pathogen

During 2011 2013, the occurrences of cotton boll rot were investigated in 200 cotton production fields distributed in 70 counties of 6 provinces in China and under different cultivation patterns. The resistance of cotton varieties against this disease was evaluated by field experiments, and pathogenicity differentiation of Phytophthora boehmeriae causing cotton boll blight was studied on cotton bolls. Results showed that cotton boll rot occurred throughout all investigated cotton fields in each survey year. Cotton boll blight caused by P. boehmeriae was the major type of cotton boll rot, which commonly occurred in the Yellow River and Yangtze River Basin regions. The 3 interplanting cultivation patterns could significantly reduce occurrence of cotton boll rot compared with the direct sowing pattern. Interplanting with 12∶2∶1 cultivation pattern (wheat cotton watermelon) showed the best control efficacy against this disease and reduced rotten bolls by 72.96%. There were significant diffe rences in the resistance of 50 cotton varieties against cotton boll rot, while the cotton varieties Han7860, Han mian103, Jinke178, Baimian1 and Zhengnongmian4 showed the best resistance with less than 3.0 rot bolls/plant. The pathogenicity differentiation of P. boehmeriae was significant on cotton bolls. This paper was a comprehensive investigation and research report on cotton boll rot in China since 1986.