海南17 a宿根巴西蕉园土壤微生物特征及土壤pH周年变化特征分析

Soil Microbial Flora and pH Annual Change Characteristics of 17 Years Continuous Cropping Banana Field in Hainan,China

香蕉是全球性的大宗经济水果,我国是香蕉生产大国也是消费大国,但产量和品质不能满足需求,每年仍需大量进口。香蕉枯萎病是影响我国香蕉产能的主要因素。巴西蕉在我国曾广泛种植,但易感香蕉枯萎病,罕有宿根蕉园。宿根蕉园栽培模式在成本控制、产期调节、环境友好等方面有巨大优势。前期研究结果显示,土壤pH以及土壤菌群与香蕉枯萎病的发生有紧密联系。本文以海南临高皇桐镇的17 a宿根巴西蕉园为样本,对该宿根蕉园、附近轮作蕉园及新开垦蕉园全生育期土壤pH及香蕉枯萎病孢子数量进行动态监测,结合土壤菌群宏基因组测序的方法对土壤中的菌群特征进行了初步探索。结果表明:宿根蕉园土壤pH高于轮作蕉园和新开垦蕉园,其pH周年变化幅度低于轮作蕉园和新开垦蕉园;宿根蕉园土壤中香蕉枯萎病孢子数目低于轮作蕉园和新开垦蕉园;在土壤细菌和真菌的菌群多样性和丰度方面,宿根蕉园均高于轮作蕉园和新开垦蕉园;宿根蕉园在全营养菌门、农杆菌门、毛霉亚门等11个细菌门级和6个真菌门级分类单位上与轮作和新垦蕉园存在显著差异;宿根蕉园在微单孢菌、芽胞杆菌、角菌根菌等土壤特征种群方面显著不同于其他2个蕉园;功能丰度热图显示,宿根蕉园土壤细菌和真菌与轮作蕉园、新开垦蕉园均有显著差异。代谢通路基因丰度分析方面显示,轮作蕉园和新垦蕉园土壤细菌在生物合成和次级代谢、转录、碳代谢、膜转运等通路明显活跃,宿根蕉园土壤真菌在细胞迁移、细胞生长和死亡、信号传导、核酸代谢、蛋白折叠储运和降解等通路显著活跃。本研究结果为阐明香蕉宿根栽培模式的内部机理奠定基础,也为废弃蕉园改造提供新的参考依据。

Banana is one of the most widely planted fruits in the world and is a staple for millions of people worldwide.China is a large banana production country but still needs to import huge amounts of banana to meet the demand.Brazil banana has been widely planted in China but it is very susceptible to Fusarium wilt(Panama disease).Ratoon banana filed(RTF)is common in foreign country and famous for its low cost,easy production period regulation and environ-mental friendliness.RTF is seldom used in China.In this study,the microbial community structure of 17-year Lingao RTF banana field was characterized through ITS and 16S rRNA gene sequencing and the reclaim banana field(RCF)and banana cane rotation field(BCF)nearby were used as the control.The results showed that the diversity and abun-dance of soil bacteria and fungi in RTF were significantly higher than that of RCF and BCF.The classification of soil microbial species showed that RTF were significantly different among 11 bacteria and 6 fungal taxonomic units such as Agrobacterium tumefaciens,actinomycetes and so on.RTF soil characteristic microorganism showed significantly dif-ferent with RCF and BCF in Micromonospora,Bacillus and Ceratobasidium.The functional abundance heat map showed that the soil bacterial activity in RTF was significantly lower than that of RCF and BCF,while the fungal activ-ity was significantly higher.Gene abundance analysis of metabolic pathways showed that soil bacteria in RCF and BCF were significantly more active in biosynthesis and secondary metabolism,transcription,carbon metabolism,membrane transfer and other pathways,while soil fungi in RTF was significantly more active in cell migration,cell growth and death,signal transduction,nucleic acid metabolism,protein folding,storage,transportation and degradation.Through the analysis of soil microbial characteristics of RTF,it would lay a foundation for clarifying the internal mechanism of banana ratoon model,and also provide a new reference for the renew of abandoned banana garden.