H.11648剑麻叶汁对桑根腐病菌可可毛色二孢的抑制作用

Inhibitory effect of Agave sisalana Perr. ex Engelm H.11648 leaf juice on mulberry root rot pathogen Lasiodiplodia theobromae Pat.

【目的】研究H.11648剑麻叶汁对桑树根腐病病菌可可毛色二孢(Lasiodiplodia theobromae Pat.)菌丝生长和分生孢子萌发的抑制效果,为大田防治桑根腐病及其他由L.theobromae侵染所致的植物病害提供理论依据。【方法】采用生长速率法和载玻片孢子萌发法测定H.11648剑麻新鲜叶汁、腐熟叶汁、灭菌叶汁及提取麻膏后的叶汁对L.theobromae菌丝生长和孢子萌发的抑制作用,并在显微镜下观察菌丝的形态变化。【结果】H.11648剑麻的4种叶汁处理均能显著抑制L.theobromae菌丝生长和分生孢子萌发(P<0.05),其中以新鲜叶汁的抑菌效果最佳,其对病菌菌丝生长与分生孢子萌发的相对抑制率分别为85.37%和85.77%;新鲜叶汁经过腐熟、灭菌和提取麻膏后抑菌效果有所下降,腐熟叶汁、灭菌叶汁及提取麻膏后的叶汁对L.theobromae菌丝生长的相对抑制率分别为79.27%、76.83%和65.79%,对分生孢子萌发的相对抑制率分别为82.32%、78.46%和60.77%。显微镜下观察发现,不同处理L.theobromae菌丝膨大畸形、易断裂,且伴随原生质渗漏。【结论】H.11648剑麻叶汁能显著抑制桑根腐病病菌L.theobromae的菌丝生长和孢子萌发,可用于大田防治桑根腐病及其他由L.theobromae菌侵染所致的植物病害。

[Objective]The inhibitory effects of Agave sisalana Perr.ex Engelm H.11648 leaf juice on mycelia growth and conidia germination of Lasiodiplodia theobromae Pat.were studied,in order to provide theoretical basis for controlling mulberry root rot and other plant diseases caused by L.theobromae Pat.in field.[Method]Inhibitory effects of fresh leaf juice,composted leaf juice,sterilized leaf juice and tigogenin-free leaf juice from A.sisalana Perr.ex Engelm H.11648 on mycelia growth and conidia germination of L.theobromae Pat.were determined by growth rate method and slide spore germination method,respectively,and the morphological changes of mycelia were observed under microscope.[Result]The results showed that,four treatments of aforementioned leaf juice could significantly inhibit mycelia growth and conidia germination of L.theobromae Pat.（P0.05）,especially fresh juice treatment with the strongest inhibitory effect,and the relative inhibition rates of mycelia growth and conidia germination were 85.37%and 85.77%,respectively.In addition,after composting,sterilizing and extracting tigogenin,the obtained leaf juice had lower inhibitory effects than fresh leaf juice.As for composted leaf juice,sterilized leaf juice and tigogenin-free leaf juice,the corresponding relative inhibition rates of mycelia growth were 79.27%,76.83%and 65.79%,respectively,and the corresponding relative inhibition rates of conidia germination were 82.32%,78.46%and 60.77%,respectively.It was found that mycelia were enlarged,malformed and fractured,and protoplasm was leaky under microscope.[Conclusion]A.sisalana Perr.ex Engelm H.11648 leaf juice have inhibitory effects on mycelia growth and conidia germination of mulberry root rot pathogen L.theobromae Pat.,so which can be used for controlling mulberry root rot and other plant diseases caused by L.theobromae Pat.in field.