Stimulating The Eggs Hatch Of Meloidogyne Incognita By Trichoderma Sp.3838

Hatching is an important event of Meloidogyne incognita,and controlling hatching is a significant method to control nematodes.In this study,it was found that strain Trichoderma sp.3838 could highly stimulate eggs hatching of M.incognita.The active metabolites were isolated and identified.The relevant genes involved in the incubation process were screened and their functions were verified by RNAi.Results showed are as follows:1.In the hatching experiment,culture filtrates of Trichoderma sp.3838 could hatch the eggs of M.incognita rapidly and efficiently.The fermentation broth heated at 100? showed the best hatching activity.The hatching rate was 3 times higher than that of the control group.In addition,the the hatching rate of J2 incubated in culture filtrates diluted 10×was 4 times higher than that of the control.2.Active compounds were isolated,identified.Eight compounds were isolated from extract of ethyl acetate.These homologues could accelerate the egg mass hatching of M.incognita in 4 days,and the hatching rate of J2 of egg mass treated with compounds HY-1,HY-2 and HY-9 were more than 90%.The hatching rate of J2 of egg mass in water control increased steadily,and the hatching rate reaching 90%needs at least 12 days.The stimulating hatching activity of 8 compounds was HY-1>HY-9>HY-2>HY-3>HY-11>HY-8.>HY-6>HY-13.3.Hatching-related genes were detected through RT-PCR under stimulating by compound HY-1.The relative expressions of sixteen related genes were significantly regulated.Genes daf-21,hch-1,eft-2,mapk1,mapk3 and let-60 were over expressed,while xyl-1 and mep-1 were under-expressed.4.After treated with dsRNA,the expressions of related genes mapkl and mapk3 was significantly down-regulated,which affected the normal hatching of egg mass of M.incognita and the survival rate of fresh hatched nematodes.When treated with dsRNA and compound HY-1,the expressions of mapkl and mapk3 were doubled,the hatching rate of J2 of egg masses was reverted,and the mortality of fresh hatched J2 decreased.Highlight:1.This study reported that strain Trichoderma sp.3838 and its metabolites can promote the eggs hatching activity of M.incognita rapidly and efficiently for the first time.2.Active compound HY-1 regulated the expressions of 16 hatching-related genes of M.incognita.The function of related genes mapkl and mapk3 in hatching process was verified by RNAi.