新疆野果林木霉分离鉴定、抑菌作用及固态发酵配方优化

Isolation and identification of Trichoderma strains, and antifungal effects and solid-state fermentation recipe optimization from Xinjiang wild fruit forest

摘要:

[背景] 新疆野苹果病害发生严重，而木霉（Trichoderma spp.）是重要的植物病害生防菌，因此可利用其对新疆野苹果病害进行防治。[目的] 分离鉴定新疆野果林木霉菌株，分析其对新疆野苹果2种病原菌的抑菌能力，为新疆野苹果专用木霉菌肥的制备提供菌种资源。[方法] 利用平板稀释法对新疆野果林4种草本植物根围木霉菌进行分离，通过形态学与分子生物学方法进行菌种鉴定，平板对峙试验检测其抑菌能力并优化木霉菌株的固态发酵配方。[结果] 共分离得到2种木霉菌共42株，分别为34株棘孢木霉（T. asperellum）和8株深绿木霉（T. atroviride）；棘孢木霉TasT01对苹果炭疽病菌（Colletotrichum gloeosporioides，Cgl）和苹果斑点落叶病病原菌（Alternaria alternaria f.sp.mali，Aal）的抑菌率分别为58.60%和57.14%；深绿木霉TatT35对Cgl和Aal的抑菌率分别为43.86%和36.90%。进一步显微镜观察发现，TasT01可通过菌丝缠绕的方式抑制2种病原菌的生长。TatT35菌株固态发酵配方为稻壳90%、麦麸10%、（NH₄）₂SO₄ 0.5%时，孢子浓度达1.0×10⁸个/g。[结论] TasT01和TatT35对新疆野苹果2种病原菌都有很好的抑制效果，固态发酵配方优化后可以提高孢子浓度，该研究结果为新疆野苹果真菌病害的生物防治提供了可借鉴的方法。

Abstract:

[Background] The Xinjiang wild apple are suffering serious diseases, and Trichoderma is an important plant disease biocontrol fungus, so it can be used to prevent and control wild apple diseases in Xinjiang. [Objective] In order to isolate and identify the Trichoderma isolates from wild fruit forests in Xinjiang, determine their antifungal ability against two pathogens of wild apples (Malus sieversii), and provide the biocontrol fungal resources for the preparation of “Special Trichoderma Biofertilizer for Xinjiang wild apple”. [Methods] Trichoderma strains were isolated by plate dilution method from the rhizosphere of 4 herbaceous plants in Xinjiang wild fruit forest. Species identification was performed by morphology and molecular biology, and the antifungal ability of Trichoderma isolates was tested by plate confrontation tests, and the solid-state fermentation formula of Trichoderma strains was optimized. [Results] The results show that 2 Trichoderma species (total 42 strains) were isolated, including 34 T. asperellum isolates and 8 T. atroviride isolates. The inhibitory rates of T. asperellum T01 (TasT01) against Colletotrichum gloeosporioides (Cgl) and Alternaria alternaria f. sp. mali (Aal) were 58.60% and 57.14%, respectively; and the inhibitory rates of T. atroviride (TatT35) to Cgl and Aal were 43.86% and 36.90%, respectively. Further microscopic observation showed that TasT01 could inhibit the growth of both pathogens through hypha coiling. The solid-state fermentation formula of TatT35 strain was 90% rice husk, 10% wheat bran, 0.5% (NH₄)₂SO₄. And the spore concentration could reach 1.0×10⁸/g spores. [Conclusion] TasT01 and TatT35 have good inhibitory effects on the two pathogens of Xinjiang wild apple, and the spore concentration significantly increased after the solid-state fermentation formula was optimized. The results provide a reference for biological control of fungal diseases of Xinjiang wild apple.