马唐生防真菌MA4的分离鉴定及其生物学特性

Isolation,Identification and Biological Characteristics of the Biocontrol Fungi MA4 for Digitaria sanguinalis

【目的】筛选防治马唐(Digitariasanguinalis)的生防真菌,挖掘其应用于杂草生物防治的潜力。【方法】采用组织分离法,从自然发病的马唐植株中分离出对马唐具有较强致病力的生防菌株,通过形态学观察、ITS、β-Tubulin、EF-1α基因序列同源性比对及其系统进化分析确定其分类地位;利用单因素试验研究其生物学特性及整株生物测定法测定马唐生防真菌对几种常见杂草的侵染效果及对常见作物的安全性。【结果】分离得到的马唐生防真菌MA4被鉴定为藤仓镰刀菌(Fusarium fujikuroi);最适合MA4生长的培养基为PDA和PSA;最适合MA4生长和产孢的培养条件为:温度28~30℃,p H值6.0~8.0,黑暗培养;MA4对马唐鲜重防效较好,达到91.4%,对看麦娘、狗尾草和钻形紫菀的鲜重抑制率分别为63.8%、80.6%、69.4%;MA4对双子叶作物相对安全。【结论】藤仓镰刀菌MA4菌株对马唐等禾本科杂草防治效果较好,对双子叶作物较安全,具有开发成生物除草剂的巨大潜力。

[Objective] To screen biocontrol fungi of Digitaria sanguinalis and explore the potential of its application in weed biological control.[Method] The biocontrol strains with strong pathogenicity to Digitaria sanguinalis were isolated from naturally diseased plants by tissue isolation method,and their taxonomic status was determined by morphological observation,sequence homology comparison and phylogenetic analysis of ITS,β-Tubulin and EF-1α gene.Biological characteristics of the biocontrol fungi was determined by single factor test.Infection effect on several common weeds and safety to common crops were also determined by whole plant bioassay.[Result] The isolated Digitaria sanguinalis biocontrol fungi named MA4 was identified as Fusarium fujikuroi.The most suitable media for MA4 growth were PDA and PSA.The most suitable culture conditions for MA4 growth and spore production were temperature of 28-30 °C,pH of 6.0-8.0 and dark culture.Fusarium fujikuroi MA4 had good control effect on Digitaria sanguinalis,the fresh weight control effect was 91.4%,and the fresh weight inhibition rates of Alopecurus aequalis,Setaria viridis and Aster subulatus were 63.8%,80.6% and 69.4%,respectively.Fusarium fujikuroi MA4 is relatively safe to dicotyledonous crops.[Conclusion] Fusarium fujikuroi MA4 strain has good control effect on grasses such as Digitaria sanguinalis and is safe to dicot crops,and it has great potential to be developed into a biological herbicide.