摘要
为了筛选获得具除草潜力的病原真菌菌株,经形态学观察和18s rDNAITS序列分析,6株分离自感病六蕊假稻的菌株被鉴定为稻平脐蠕孢Bipolaris oryzae。采用培养皿生测法和盆栽生测法分别评价其发酵液毒素和菌丝体悬浮液的除草活性,同时用盆栽生测法测定了菌丝体悬浮液对主要作物的安全性。试验结果表明:6株稻平脐蠕孢培养14 d的发酵液对稗草根长、芽长均有很高的抑制作用,根长和芽长最高抑制率分别为100%和80.38%。培养7 d的菌丝体悬浮液对稗草的感病率、感病指数、株高抑制率、鲜重抑制率最高可达100%、72.00、50.29%和63.31%。6株稻平脐蠕孢菌丝体悬浮液对稗草、千金子、六蕊假稻、鸭舌草、矮慈姑、野荸荠具有不同程度的致病性,对双穗雀稗、异性莎草、看麦娘不致病。6株稻平脐蠕孢对主要农作物安全或致病性很弱,具有进一步开发为生物除草剂的潜力。
In order to obtain potential pathogenic fungi for biological control of weeds, we isolated from natural-infected Leersia hexandra six strains which was then identified as Bipolaris oryzae via morphology and rDNA ITS sequence analysis. Herbicidal activity of toxins in culture filtrates and mycelial suspension were evaluated by petri dish and pot bioassay, and the safety to main crops of mycelia suspension was also tested using pot bioassay. Results showed that the 14 day culture filtrates of the six strains were highly inhibitory against growth of barnyardgrass, Echinochloa crusgalli （L.） Beauv., with inhibitory rate of 100% on roots and 80.38% on shoots respectively. Disease incidence, disease infection index, inhibition rates of plant height and fresh weight of barnyardgrass treated with 7 day mycelia suspension reached 100%, 72,50.29% and 63.31%, respectively. The 7 day mycelia suspension was pathogenic with various degrees to E. crusgalli, Leptochloa chinensis, L. hexandra, Monochoria vaginalis, Sagittaria pygmaea and Eleocharis plantaginerformis, but not pathogenic to Paspalum distichum, Cyperus difformis and .41opecurus aequalis. The six strains were safe or weak pathogenic to main crops, and showed potential as biological herbicides.
出处
《中国生物防治学报》
CSCD
北大核心
2013年第1期110-116,共7页
Chinese Journal of Biological Control
基金
国家自然科学基金项目(31101454)
中央级公益性科研院所基本科研业务费专项资金项目(2012RG003-2)
浙江省自然科学基金项目(Y3100237)
"十二五"农村领域国家科技计划项目(2012BAD19B02)
"863"计划项目(2011AA10A206)
关键词
六蕊假稻
稻平脐蠕孢
分子鉴定
致病性
Leersia hexandra
Bipolaris oryzae
molecular identification
pathogenicity
