四川带状套作大豆种腐病菌的分离与鉴定

明确套作大豆种腐病菌的种类及其致病性,对于防治大豆种腐病,提高大豆产量和品质具有重要意义.于2016～2018年从四川仁寿、崇州、南充等地收集大豆种腐病的病籽粒,通过组织分离与纯化,基于形态特征、rDNA ITS和EF-1α序列分析以及致病性测定,鉴定四川套作大豆种腐病的病原菌种类.结果表明:分离获得的70株菌株被鉴定...

Isolation and identification of the fungi causing soybean seed decay in maize-soybean relay strip intercropping in Sichuan

For effective management of soybean seed decay and improvement of soybean yield and quality, it issignificantly important to find out the fungal species and their pathogenicity of soybean seed decay in maize-soy-bean relay strip intercropping. During 2017-2018, the infected soybean seeds were collected from Renshou, Chong-zhou, Nanchong of Sichuan Province, China, respectively. The fungi were isolated from these infected seeds and pu-rified by hypha tip method, and identified based on morphological characteristic and sequence analysis of rDNA ITSand EF-1α genes. The pathogenicity tests of the representative isolates were further conducted. Our results showedthat a total of 70 isolates were identified as 5 fungal species including Fusarium fujikuroi, F. equiseti, F. asiaticum,Diaporthe phaseolorum and D. phaseolorum var. caulivora, with the separation frequency of 62.56 %, 21.43%,10.00 %, 4.29 % and 1.43 %, respectively. Furthermore, the pathogenicity tests showed that all of the representa-tive isolates belonging to five specie were able to cause seed decay of the intercropped soybean cultivar ND12 andreduced seed germination and germ length. Fusarium asiaticum and D. phaseolorum had the highest mycelium cov-erage area, and disease incidence with the disease index of 100. This study firstly reports that the Fusarium spp.and Diaporthe spp. are the dominant pathogens of soybean seed decay in the maize-soybean relay strip intercrop-ping system, which will provide basis for breeding of soybean resistant cultivar and disease management.