不同抑制性土壤真菌菌株对大豆胞囊线虫的抑制作用

利用稀释分离法,从抑制性土壤中分离获得真菌菌株,研究不同菌株对大豆胞囊线虫的抑制效果。结果表明,获得的100株真菌中有5个菌株对大豆胞囊线虫胞囊孵化和二龄幼虫(J2)具有抑制活性,分别是Dq012、Dq059、Dq003、Dq030和Dq101。经Dq012发酵液处理后,大豆胞囊线虫J2的校正死亡率达到80.84%,经其他4株真菌处理后校正死亡率均在70%左右。Dq012发酵液对胞囊孵化的相对抑制率达到87.69%,Dq003和Dq030发酵液对胞囊孵化的相对抑制率也在80%以上。用5个菌株的发酵液包衣处理大豆种子,能够抑制大豆胞囊线虫的繁殖,其中菌株Dq059的抑制作用最强,Dq012次之,Dq030的抑制作用最弱,抑制率分别为83.05%、80.58%和41.52%。综上所述,菌株Dq012对大豆胞囊线虫的抑制活性最高,其他4株效果接近,但Dq030对胞囊形成的抑制效果一般。

Suppression of Different Fungus Strains in Suppressive Soil on Heterodera glycines

Fungi could reduce nematode population by their antagonistic behavior and showed a great potential as biocontrol agents.The strains Dq012,Dq059,Dq003,Dq030 and Dq101 were isolated from nematode-suppressive soil by dilution.The effects of different strains on egg hatching and activity of second stage juvenile(J2) of Heterodera glycines were tested.The results showed that the corrected mortality rate of J2 was 80.84% when treated by Dq012,and about 70% by the other strains.The suppressive percentages of cyst hatching by Dq012,Dq059,Dq003,Dq030 and Dq101 were 87.69%,76.54%,87.31%,82.69% and 73.58%,respectively.The strains could disturb cyst formation on the surface of soybean root in the field.The suppression actions of Dq059 and Dq030 were the strongest and the weakest,respectively,with inhibition rates of 83.05% and 41.52%.The inhibition rate of Dq012 on cyst formation was 80.58%.In conclusion,the strain Dq012 had the highest inhibitory activity against Heterodera glycines,while the other four were similar,except that Dq030 was less effective in disturbing cyst formation.