苹果树皮内生真菌的分离及其对腐烂病的生物防治潜力

为了明确苹果树皮中内生真菌的种类及其对苹果树腐烂病菌的抑制作用,对25年生富士苹果健康树皮中的内生真菌进行了分离和初步鉴定,并通过室内抑菌试验和田间保护作用试验测定其内生真菌对苹果树腐烂病菌的抑制作用。分离到的126株内生真菌分属于13个属,主枝中分离到的内生真菌的种类和数量较多;对峙试验中对苹果树腐烂病菌的抑菌率在40%以上的有24株,其中87.5%的菌株为链格孢属真菌。Al 6的培养滤液对腐烂病菌菌丝生长抑制作用较强,抑制率为83.76%;Al 58对其孢子萌发抑制作用较大,抑制率为82.42%;Al 67产生的挥发物质对腐烂病菌菌丝生长的抑制作用较大,为24.41%。田间试验结果显示,用拮抗性内生真菌预先占位接种苹果树枝干,能有效抑制腐烂病菌的侵入和病斑的扩展,Al 107的抑制作用最强。

Isolation of endophytic fungi from apple bark and their potential for biological control of Valsa ceratosperma

In order to understand the species of endophytic fungi in apple tree bark and their inhibitory effects on Valsa ceratosperma, endophytic fungi in 25 years Fuji symptomless apple bark were isolated and preliminary identified, and their inhibitory effects on V.ceratosperma were tested both through antibiotic test in Petri dish and protection test in the field. The 126 endophytic fungus strains were identified into 13 genera. Most species of endophytic fungi were isolated from bough. In the dual culture assays 24 endophytic fungus isolates showed inhibition rate above 40% and 87.5% of the isolates belong to Alternaria sp. The culture filtrate of Al 6 had better inhibition effect on the mycelial growth of V.ceratosperma, while Al 58 had better inhibition effect on conidia germination, with the inhibition rate of 83.76% and 82.42%, respectively. The volatile compounds produced by Al 67 had better inhibitory effect on the mycelial growth of V.ceratosperma, the inhibition rate reached 24.41%. The field test results showed that when the antagonistic endophytic fungi were firstly inoculated on apple tree, the followed infection and lesion extension of V.ceratosperma could be inhibited effectively. The most effective one was Al 107, which totally inhibited the infection of V.ceratosperma under the condition of artificial inoculation.