西南桦苗木猝倒病生防菌的筛选及鉴定研究

Isolation and Identification of Damping-off Antagonist of Betula alnoides Seedlings

采用组织分离法和稀释平板法对西南桦猝倒病发生区健康苗木组织、根际土壤及咖啡壳堆肥化基质进行菌种分离和分子鉴定。将分离获得的17株菌株与西南桦苗木猝倒病病原菌尖孢镰刀菌和腐皮镰刀菌进行平板对峙实验,筛选病原拮抗菌。结果表明,筛选出的真菌5#、7#及细菌BJ、JC1对西南桦苗木猝倒病原菌尖孢镰刀菌和腐皮镰刀菌具有较强抑制效果。其中真菌5#和7#的抑菌率分别为91.30%和90.12%;细菌BJ和JC1抑菌带较宽,对峙4天分别达0.4 cm和0.5 cm,抑菌率分别为80.4%和78.6%,且BJ抑菌效果更好;真菌与细菌比较,拮抗真菌5#和7#比拮抗细菌BJ和JC1抑制热区西南桦苗木猝倒病菌效果更好。通过对峙实验筛选出的5#、7#、BJ和JC1拮抗菌,对热区防治苗木猝倒病及生防制剂的开发应用具有参考价值。

The tissue isolation and dilution-plate were used on healthy seedlings tissue, rhizosphele soil and coffee shell composting matrix for isolating antagonists of damping-off disease of Betula alnoides seedlings ; and the isolated strains were identified through molecular method. The confront culture was conducted between 17 isolated strains and the pathogens Fusarium oxysporum and Fusarium solani to screen for antagonists. The results indicated that, the fungus strains 5#, 7# and bacteria BJ and JC1 showed promising inhibition effects on two pathogens. The inhibi- tion rates of fungus strains 5# and 7# to the pathogens strains had the inhibition belts of 0.4 cm and 0.5 cm, tively, and BJ showed the better inhibition effect. The than bacterial strains. were 91.30 % and 90. 12 % respectively, two bacteria with the inhibition rates of 80.40 % and 78.60 % respec- inhibition effects of two isolated fungal strains were better