抗香蕉枯萎病品种的抗性机理及对土壤微生物群落的影响

发布时间：2018-03-18 03:31

本文选题：香蕉枯萎病　切入点：品种　出处：《海南大学》2016年硕士论文　论文类型：学位论文

【摘要】：由尖孢镰刀菌香蕉专化型(Fusarium oxysporum f. sp. cubense, FOC)侵染引起的香蕉土传枯萎病的爆发与蔓延,严重限制了香蕉产业的发展,抗病品种的选育是防治该病的重要措施。本试验首先通过盆栽试验研究了接种病原菌后抗枯萎病香蕉品种防御酶活性及土壤可培养微生物数量的变化,然后利用PCR—-变性梯度凝胶电泳(DGGE)、MiSeq高通量测序等技术手段对不同品种大田土壤微生物区系群落结构和多样性进行了深入探究。探讨了抗病品种的抗性机理及其对土壤微生物生态的影响,以期为香蕉抗病的育种提供理论基础。主要研究结果如下：(1)香蕉抗病品种的抗病性及抗病机制研究在盆栽条件下,向土壤中接种不同浓度FOC4,‘宝岛218’和‘南天黄’香蕉发病率随孢子液浓度的增加而增大,当接种的孢子液浓度为103cfu/g土时,‘巴西蕉’发病率已达40%,而抗病品种发病率约为5%。当接种的孢子液浓度为104cfu/g土时,‘巴西蕉’发病率已达90%,而抗病品种的发病率分别为25%和20%。当接种的孢子液浓度为10Scfu/g土时,抗病品种的发病率也分别达到了55%和45%。这与抗病品种在田间的表现是相一致的,说明土壤中香蕉枯萎病病菌的数量和积累不会因为香蕉品种的改变而改变。另外在本试验中抗香蕉枯萎病品种及感病品种香蕉地上及地下部分残体浸提液均能促进孢子萌发及菌丝生长,且随着浸提液浓度的增加促进率增加,同时‘巴西蕉’高于‘宝岛218’和‘南天黄’,但差异不明显。(2)抗枯萎病香蕉品种抗病的生理学机制抗香蕉枯萎病品种受到香蕉枯萎病病原菌侵染后,‘宝岛218’和‘南天黄'POD活性变化大于‘巴西蕉’。各品种PPO活性都出现升高,且‘宝岛218’和‘南天黄’峰值显著大于‘巴西蕉’。两个抗病品种‘宝岛218’和‘南天黄’的几丁质酶和β-1,3-葡聚糖酶活性增加量都大于‘巴西蕉’,其中两个抗病品种‘宝岛218’和‘南天黄’p-1,3-葡聚糖酶活性最大值都达到未接种时的3倍。证明香蕉的抗性与POD、PPO、几丁质酶和p-1,3-葡聚糖酶活性正相关。各抗性品种PAL活性变化一致,并且‘宝岛218’和‘南天黄’与‘巴西蕉’之间存在显著差异,表明PAL活性和香蕉的抗病性存在一定的相关性。(3)香蕉抗病品种对土壤微生物生态的影响抗病品种真菌丰富度低于感病巴西蕉,细菌丰富度和多样性高于感病巴西蕉。高通量数据显示,在真菌门水平上,与感病品种相比较抗病品种根际和土体土壤环境中担子菌门(Basidiomycota)和接合菌门(Zygomycota)的相对丰度较高,子囊菌门(Ascomycota)的相对丰度较低。在细菌门水平上,与感病品种相比较抗病品种根际和土体土壤环境中拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)和厚壁菌门(Firmicutes)的相对丰度较高,纤维杆菌门(Fibrobacteres)和绿弯菌门(Chloroflexi)相对丰度较低。抗病品种土体和根际Fusarium均和感病品种‘巴西蕉’没有显著差异。
[Abstract]:The Banana Fusarium oxysporum biotypes (Fusarium oxysporum f. sp. cubense, FOC) the outbreak and spread of banana caused by infection of soil borne Fusarium wilt, seriously restrict the development of the banana industry, breeding disease resistant varieties is an important measure for the prevention of the disease. In this study, a pot experiment was conducted to study after inoculation of Fusarium wilt resistance disease of banana varieties defense enzymes and soil microbial quantity change the culture, then using PCR denaturing gradient gel electrophoresis (DGGE), MiSeq high-throughput sequencing technology on different varieties of field soil microbial community structure and diversity have been studied. Discussed the resistance mechanism of resistant varieties and its influence on soil microbial ecology, in order to provide theoretical basis for the breeding of banana resistance. The main results are as follows: (1) banana cultivars resistant to disease resistance and resistance mechanism in the pot Under the condition, to the soil inoculated with different concentrations of FOC4, the "218 island" and "Southern yellow banana disease" with increasing rate of spore concentration increases, when the spore concentration inoculated is 103cfu/g soil, "Brazil Banana 'incidence rate has reached 40%, while the resistant varieties incidence rate is about 5%. when the spores the concentration of inoculation is 104cfu/g soil," Brazil Banana' incidence rate has reached 90%, and the incidence rate of the disease resistant varieties were 25% and 20%. respectively when the spore concentration inoculated is 10Scfu/g soil, the incidence rate of resistant varieties were also reached 55% and 45%. with the resistant varieties in the field of the performance is consistent that, and not the number of accumulation of Fusarium Wilt of banana in soil changed because of the change of banana varieties. Other varieties in this experiment against Banana Fusarium Wilt and susceptible varieties of banana ground and underground parts of residue extract could promote the germination of spores and mycelium Growth, and with the increasing concentration of the water extracts of the promotion rate increases, while the "Brazil banana" is higher than "218 island" and "Southern Yellow", but the difference is not obvious. (2) physiological resistance to Fusarium Wilt of banana varieties resistant mechanism of varieties resistant to Fusarium Wilt of banana Fusarium Wilt of banana by bacteria infection, "'218' and 'change of Southern Yellow'POD activity than" Brazil banana varieties ". The activity of PPO were increased, and the" 218 island "and" Southern Yellow' peak was significantly greater than that of "Brazil banana". Two cultivars' Taiwan 218 'and' South Yellow 'chitinase and -1,3- glucanase activity increased the volume is greater than the "Brazil banana", one of the two resistant cultivars "island 218" and "Southern Yellow glucanase activity' p-1,3- maximum value reached 3 times. When the inoculation proved resistant and POD, banana PPO, chitinase and glucanase activity is p-1,3- The change is consistent. PAL activity of the resistant variety ", and there are significant differences between the 218 island" and "Southern Yellow" and "Brazil banana", shows that there is a correlation between the resistance and the activity of PAL. (3) banana banana resistant varieties on the microbial ecology of resistant fungi richness lower than susceptible Brazil banana, bacterial richness and diversity is higher than that of the susceptible Brazil banana. High-throughput data show that in the eumycota level, compared with the susceptible cultivar basidiomycete resistant varieties in rhizosphere and bulk soil environment in the door (Basidiomycota) and Zygomycota (Zygomycota) of the relatively high abundance of Ascomycota (Ascomycota) relative low abundance of bacteria. In gate level, compared with the susceptible cultivar bacteriodetes resistant cultivars in rhizosphere and bulk soil (Bacteroidetes), actinobacteria (Actinobacteria) and Firmicutes (Firmicutes) relative The relative abundance of Fibrobacteres and Chloroflexi is relatively low. The Fusarium of soil and rhizosphere of resistant varieties is not significantly different from that of susceptible cultivar 'Brazil Banana'.

【学位授予单位】：海南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S436.68;S154.3

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