西南地区玉米穗腐病病原分离鉴定及接种方法研究

Identification of Pathogen Causing Maize Ear Rot and Inoculation Technique in Southwest China

2010-2011年,从我国西南地区16个市(县)主要玉米产区采集玉米穗腐病标样190份,采用组织分离培养法分离得到393个菌株,将传统形态学分类方法与分子生物学方法相结合,共鉴定出15个种属,其中以拟轮枝镰孢菌(Fusarium verticillioides)分离频率最高为40.20%,为优势菌株;其次为禾谷镰孢菌(Fusarium graminearum),分离频率为15.01%。选用优势菌株拟轮枝镰孢菌采用花丝注射法、籽粒注射法、花丝喷雾法3种方法进行了穗腐病接种方法筛选,结果表明,籽粒注射法有利于病原菌的侵染发病,发病程度适中,是一种比较理想的接种方法。采用此方法对西南主要推广品种进行了抗病性鉴定,品种间对拟轮枝镰孢菌抗性存在显著差异,无高抗品种,表现好的品种有正大619,正大818,迪卡007,农乐988,正红505和神珠7号等6份。

393 isolates belonging to 15 species were isolated from 190 samples collected from 16 locations in southwest China in 2010 -2011. The separating rate of Fusarium verticillioides was the highest, reaching to 40.20 %, and the second was Fusarium gramlnearum with 15.01 % of separating rate. Three methods, including silk channel injection, silk channel spraying and kernel injection, were compared for screening the best inoculation method. The results showed that kernel injection caused higher severity compared with other three methods. In addition, 44 main hybrids planted in Southwest China were evaluated for resistance to ear rot by kernel injecting with Fusarium verticillioides in field. There was significant difference in the level of resistance among these hybrids. None of high resistant hybrid was screened, meanwhile Zhengda 619,Zhengda 818, Dika 007, Nongle 988, Zhenghong 505, Shenzhu 7 were indentified to be resistant hybrids.