香蕉套种黑皮冬瓜对香蕉枯萎病的防控效果及土壤微生物群落的影响

【目的】探索香蕉套种黑皮冬瓜后对香蕉枯萎病的防控效果及蕉园土壤微生物群落的影响，为香蕉枯萎病的综合防控提供理论参考。【方法】以抗（耐）枯萎病香蕉品种桂蕉9号、易感枯萎病香蕉品种桂蕉1号为试验材料，在上一造香蕉枯萎病发病率大于50%的蕉园进行随机区组试验，设桂蕉9号套种黑皮冬瓜、桂蕉9号单作、桂蕉1号套种黑皮冬瓜和桂蕉1号单作4个处理，调查香蕉枯萎病发病率、香蕉和冬瓜采收后产量，检测冬瓜采收后蕉园土壤的理化性质和微生物数量，并通过高通量测序技术研究不同处理间土壤细菌群落结构和组成的差异。【结果】桂蕉9号套种黑皮冬瓜、桂蕉9号单作、桂蕉1号套种黑皮冬瓜和桂蕉1号单作香蕉枯萎病发病率分别为1.48%、14.44%、52.96%和70.00%。香蕉套种黑皮冬瓜后虽平均单株产量与单作香蕉相比差异不显著（P>0.05），但折合每公顷香蕉产量因枯萎病发病率的降低而有所增加。桂蕉9号和桂蕉1号套种黑皮冬瓜后土壤pH分别较单作该香蕉品种显著提高24.00%和19.45%（P<0.05，下同）、土壤电导率（EC）显著下降78.48%和72.55%、土壤碱解氮含量显著升高72.92%和72.73%、土壤细菌及放线菌数量显著增加，Chaol指数和Shannon指数显著提高，Simpson指数显著降低。套种黑皮冬瓜提高了土壤细菌变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）、酸杆菌门（Acidobacteria）、芽单胞菌门（Gemmatimonadetes）和拟杆菌门（Bacteroidetes）的相对丰度，降低了绿弯菌门（Chloroflexi）和放线菌门（Actinobacteria）的相对丰度。套种黑皮冬瓜改变了土壤细菌群落结构，增加了土壤细菌的多样性及丰富度。抗（耐）枯萎病香蕉品种套种黑皮冬瓜的防病效果比感病品种更明显。【结论】抗（耐）枯萎病香蕉品种套种黑皮冬瓜可通过提高土壤pH、降低土壤电导率、提高土壤碱解氮含量、改变土壤细菌群落结构达到降低香蕉枯萎病发病率的目的。抗（耐）枯萎病香蕉品种套种黑皮冬瓜种植模式可在广西香蕉枯萎病病区推广应用。

Effects of interplanting of banana with black-skinned wax gourd on controlling Fusarium wilt and soil microbial community

【Objective】An attempt was made to explore the effects on controlling Fusarium wilt and the structure of soil bacterial community after banana was intercropped with black-skinned wax gourd, to provide theoretical reference for the comprehensive controlling of banana Fusarium wilt.【Method】The resistance(tolerance) Fusarium wilt variety Guijiao 9 and susceptible Fusarium wilt variety Guijiao 1 were used as experimental materials. A randomized block experiment was carried out in a banana orchard with an incidence of Fusarium wilt more than 50%. There were four treatments, Guijiao 9/black-skinned wax gourd intercropping, Guijiao 9 monoculture, Guijiao 1/black-skinned wax gourd intercropping and Guijiao 1 monoculture. Investigated incidence of banana Fusarium wilt, postharvest yield of banana and wax gourd, collected the orchard soil after the balck-skinned wax gourd were harvested, detected the physical and chemical properties of soil and the number of microorganisms. High-throughput sequencing technology was used to determine the soil bacterial community structure and composition among different treatments.【Result】The incidences of Fusarium wilt were 1.48%, 14.44%, 52.96% and 70.00% respectively, after Guijiao 9/black-skinned wax gourd intercropping, Guijiao 9 monoculture, Guijiao 1/black-skinned wax gourd intercropping and Guijiao 1 monoculture. There was no significant difference in the average yield of banana/black-skinned wax gourd intercropping and banana monoculture(P>0.05), but the banana yield per hectare increased due to the decrease of the incidence of Fusarium wilt. Compared with different resistant banana varieties monoculture, the pH value of Guijiao 9 and Guijiao 1/black-skinned wax gourd intercropping significantly increased by 24.00% and 19.45%, respectively(P<0.05), the soil electrical conductivity(EC) value significantly decreased by 78.48% and 72.55%, and the content of soil alkali-hydrolyzable nitrogen significantly increased by 72.92% and 72.73%. The number of soil bacteria and actinomycetes increased significantly, Chaol index and Shannon index increased significantly, and Simpson index decreased significantly. Different resistant banana varieties(resistant and susceptible varieties)/black-skinned wax gourd intercropping increased the relative abundance of Proteobacteria, Firmicutes, Acidobacteria, Gemmatimonadetes and Bacteroidetes of soil bacteria, and decreased the relative abundance of Chloroflexi and Actinobacteria. Different resistant banana varieties(resistant and susceptible varieties)/black-skinned wax gourd intercropping changed the structure of soil bacterial community and increased the diversity and richness of soil bacteria. The effect of interplanting black-skinned wax gourd with Fusarium wilt resistance(tolerance) banana varieties was more obvious than that of susceptible varieties.【Conclusion】Fusarium wilt resistance(tolerance) banana varieties/blackskinned wax gourd intercropping can reduce the incidence of banana Fusarium wilt by increasing soil pH, reducing EC value, increasing soil alkali-hydrolyzable nitrogen content and changing soil microbial community structure. Fusarium wilt resistance (tolerance) banana varieties/black-skinned wax gourd intercropping can be promoted in in banana Fusarium wilt disease areas in Guangxi.