香蕉植株根区土壤的真菌多样性分析

尖孢镰孢菌古巴专化型(Fusarium oxysporum f.sp.cubense)是香蕉枯萎病的病原菌,该菌是一种土壤习居菌,了解香蕉根区土壤中真菌多样性及镰孢菌属(Fusarium)真菌所占比例,对如何减少土壤中的病原菌、预防香蕉枯萎病的发生有重要的指导意义。该文通过采集不同宿根年限的香蕉健康植株和枯萎病植株的根区土壤,利用高通量测序技术测定土壤样品中的真菌种群。结果表明:(1)同一宿根年限的香蕉植株中,健康植株根区土壤中所获的reads及OTUs数量均高于枯萎病植株,说明健康植株根区土壤的真菌多样性丰富于枯萎病植株。(2)除了一年生香蕉枯萎病植株以担子菌门(Basidiomycota)为主外,其他土壤样品中均以子囊菌门(Ascomycota)为主,其中的丛赤壳科最高相对丰度来自三年生健康植株的根区土壤(26.02%),其次是五年生的枯萎病植株根区土壤(15.56%)。(3)在丛赤壳科中,镰孢菌属在三年生健康植株土壤中的相对丰度最高(2.54%),在其他样品中的相对丰度在0.1%～0.65%之间;在镰孢菌属中,腐皮镰孢菌(Fusarium solani)的相对丰度(0～1.59%之间)高于尖孢镰孢菌(F.oxysporum),尖孢镰孢菌仅占很小的比例(相对丰度0～0.08%之间)。可见,在不同香蕉植株的根区土壤中,健康植株的根区土壤真菌多样性高于枯萎病植株,无论是健康植株还是枯萎病植株的根区土壤中,作为香蕉枯萎病病原菌的镰孢菌属或尖孢镰孢菌的群体均不占主导地位。

Analysis of fungi diversity in root zone soil of banana plants

Fusarium oxysporum f. sp. cubense is the pathogen of banana fusarium wilt which is a soil habitual fungus. Understanding the diversity of fungi and the proportion of Fusarium in the soil of banana root zone has important guiding significance for reducing the pathogens in the soil and preventing the occurrence of banana fusarium wilt. The root zone soil samples from banana healthy and fusarium wilt plants with different perennial years were collected and the fungal populations in the soil samples were determined by high throughput sequencing technique. The results were as follows:(1)Among banana plants with the same perennial root age, the number of reads and OTUs in the samples from healthy plants was higher than that from fusarium wilt plants, indicating that the diversity of fungi in the root zone soil of healthy plants was richer than that from fusarium wilt plants.(2)Except for phylum Basidiomycota was dominant in annual banana fusarium wilt plant, Ascomycota was the dominant phylum in other soil samples. The highest relative abundance of family Nectriaceae was in the root zone soil of triennial healthy plant(26.02%), followed by that of five-year-old fusarium wilt plant(15.56%).(3)Among genus family Nectriaceae, the highest relative abundance of Fusarium was 2.54% in the sample from triennial healthy plant, and that from other samples ranged from 0.1% to 0.65%. Among genus Fusarium, the relative abundance of Fusarium solani(0-1.59%)was higher than that of F. oxysporum, whose relative abundance only ranged from 0 to 0.08%. It was concluded that the diversity of fungi in the root zone soil of banana healthy plants was higher than that of fusarium wilt plants. The population of Fusarium or F. oxysporum, which were the pathogen of banana fusarium wilt, was not the dominant genus or species in root zone soil from both healthy and fusarium wilt plants.