健康与感染青枯病烟株根际土壤与茎秆真菌群落结构与多样性

为研究感染青枯病后烟株根际土壤与茎秆真菌群落结构与多样性的变化,对健康和感染青枯病烟株的根际土壤、病株茎秆发病组织和健株茎秆健康组织等样品中真菌ITS区的rDNA进行了PCR扩增、用Illumina MiSeq测序技术对扩增DNA片段进行高通量测序,并分析不同样品的真菌群落组成与多样性。结果表明,所有烟株根际土壤中优势门为子囊菌门Ascomycota和接合菌门Zygomycota;所有茎秆样品中优势门为担子菌门Basidiomycota和子囊菌门。在属水平,被孢霉属Mortierella、镰刀菌属Fusarium和隐球菌属Cryptococcus为所有土壤中的主要菌属,Boeremia主要存在于发病烟株根际土壤中,而木霉属Trichoderma主要存在于健康烟株根际土壤。发病茎秆病害组织中优势属为小画线壳属Monographella、隐球菌属、鬼伞属Coprinopsis和赤霉属Gibberella;发病茎秆病健交界处组织中优势属为隐球菌属、红酵母属Rhodotorula和小画线壳属。健康烟株茎秆组织中优势属为隐球菌属、链格孢属Alternaria和红酵母属;健康烟株中与发病茎秆病健交界处组织等高茎秆中优势属为镰刀菌属、隐球菌属、链格孢属和Gibellulopsis。青枯菌侵染烟株后根际土壤、发病茎秆病害组织和发病茎秆病健交界处组织的真菌群落中物种丰富度与多样性均显著提高,且发病茎秆病害组织与发病茎秆病健交界处组织真菌群落的变化大于根际土壤。研究结果为烟草青枯病的生物防治提供了参考。

Fungal community structure and diversity of the rhizosphere soil and stems of healthy and diseased tobacco plants infected with bacterial wilt

In order to study the changes of fungal community structure and diversity in the rhizosphere soil and stem tissue of tobacco plants infected with bacterial wilt, we amplified the rDNA of fungal ITS region in the rhizosphere soil, diseased stem tissue and symptomatic asymptomatic junction stem tissue, as well as the rhizosphere soil and stem tissue of healthy tobacco plants. The amplified fragments were sequenced using Illumina MiSeq sequencing technique. Then the fungal community structure and diversity in different samples of healthy and diseased tobacco plants were analyzed. The results showed that the dominant phyla in rhizosphere soil samples of all the tested tobacco plants were Ascomycota and Zygomycota, and the dominant phyla in stem tissue samples were Basidiomycota and Ascommycota. Mortierella, Fusarium and Cryptococcus were the main fungal genera in all rhizosphere soil samples. Boeremia mainly existed in the rhizosphere soil of diseased tobacco plants, while Trichoderma mainly existed in that of the healthy tobacco plants. Monographella, Cryptococcus, Coprinopsis and Gibberella were dominant genera in the diseased stem tissues; Cryptococcus, Rhodotorula and Monogragraphella were dominant genera in the symptomatic asymptomatic junction stem tissue. In the healthy tobacco plants, the dominant genera were Cryptococcus, Alternaria and Rhodotorula in healthy stem tissues, and Fusarium, Cryptococcus, Alternaria and Gibellulopsis in the healthy stem tissue at the same height with the symptomatic asymptomatic junction stem tissue. Fungal richness and diversity in the rhizosphere soil, diseased stem tissue and symptomatic asymptomatic junction stem tissue increased significantly after bacterial wilt infection. These results provided a reference for biological control of tobacco bacterial wilt.