施用不同生物有机肥对连作黄瓜枯萎病防治效果及其机理初探

摘要

Two kinds of strains , Bacillus subtilis SQR9 and Trichoderma harzianum T37 which are antagonistic to Fusarium oxysporum, were used in this study .Bioorganic fertilizers containing the antagonists either in nursery or in transplanted soils were applied to investigate the effects of three types of bio-organic fertilizers ( BIOⅠ, BIOⅡand BIOⅢ) on the controlling efficiency of Fusarium wilt in cucumber growth , and profile the colonization of these two strains on cucumber roots .Results showed:1 ) As control , the incidence rate in pot experiment was assigned 100%, and the treatment with organic fertilizer ( OF) was 88.2%, while the incidence rates of treated with BIOⅠ, BIOⅡBIOⅢ were 51.0%, 19.6% and 13.7%, respectively .2 ) The biomasses of cucumber treated with BIOⅠ, BIOⅡand BIOⅢ, were 2.55 , 2.46 and 2.58 times of the control , respectively .3 ) Application of BIOⅡand BIOⅢ could reduce the quantity of Fusarium oxysporum in rhizosphere of cucumber to ×103 copies/g soil detected by real-time PCR, but ×107 copies/g soil of Fusarium oxysporum was found in the control .SQR9 and T37 could be effectively colonized on the cucumber root surface and thus occupied the ecological sites in the rhizosphere .Study suggested that application of BIO could not only effectively suppress the occurrence of Fusarium wilt in cucumber , but also promote the cucumber growth .%采用营养钵育苗和盆钵试验的方法，研究了以枯草芽孢杆菌SQR9和哈茨木霉T37这两株拮抗菌制成的三种生物有机肥（ BIOⅠ、BIOⅡ和BIOⅢ）对黄瓜生长、土传枯萎病防治效果及其生防菌株在黄瓜根系中的定殖情况的影响。结果表明，1）未施用生物有机肥的对照处理（CK）完全发病，有机肥处理（OF）发病率高达88.2％。施用BIO处理都不同程度地降低了黄瓜土传枯萎病的发病率，施用生物有机肥BIOⅠ、BIOⅡ和BIOⅢ后发病率分别降至51.0％、19.6％、13.7％。2）与对照相比，BIOⅠ、BIOⅡ和BIOⅢ处理能够显著提高黄瓜生物量，分别是对照的2.55、2.46和2.58倍。3）菌株SQR9和T37通过有效的根际定殖降低了病原真菌对根系的侵染，荧光定量PCR （ real-time PCR）测定黄瓜根际尖孢镰刀菌数量的结果表明，施用BIOⅡ和BIOⅢ能够将病原菌数量控制在×103 copies/g土，而对照土壤高达×107 copies/g土。