Study On Clubroot Resistance Of Different Cabbage And Chinese Cabbage Varieties And Detection Of Plasmodiophora Brassicae In Soils

Clubroot disease, caused by the obligate plant pathogen Plasmodiophora brassicae Woron., is one of the most economically important diseases affecting cruciferous crop in the world. In recent years, it expands quickly in our country, and causes great economic losses to the cruciferous vegetable production. Breeding disease-resistant varieties is one of the most useful methods to prevent clubroot, therefore the key point is accurate resistant identification. In order to prevent the spread of clubroot effectively, accurate and rapid detection of the content of Plasmodiophora brassicae in soils becomes particularly important.In this study, inoculation of Plasmodiophora brassicae in seedling stage in room and marker-assisted selection are used to identify clubroot-resistance of different cabbage and Chinese cabbage, and detection of Plasmodiophora brassicae by PCR in naturally infested soils. The results are as follows:1、Inoculation of mixing resting spores of the pathogen with soil in seedling stage in room and marker-assisted selection are used to identify the clubroot-resistance of five clubroot-resistance cabbage varieties and five clubroot-resistance Chinese cabbage varieties. Soil inoculation showed five Chinese cabbage varieties are resistant, and four cabbage varieties (Shengzhen, Zhouye Cabbage, Nanbao, Dananmu) are resistant and one cabbage variety (Jinjing Cabbage) is susceptive, marker-assisted selection showed all varieties in this study are resistant, and all varieties have Crr3gene, three varieties (CR-Yingxiong, CR-Manfu, Jinjin) have Crrl gene at the same time. Resistant identification by marker-assisted selection is feasible.2、We designed a pair of specific primers (PBF:5’-CAAAGGTGGAAAGATG GTGC-3’,PBR:5’-CGGTGCTGGCGTTGATGT-3’) by the genes fragment of Plasmodiophora brassicae (accession number:D85819), and detected Plasmodiophora brassicae in naturally infested soils. The sensitivity of the primers is30ng/μL, and300pg/μL can be detected in soils. This showed the primers can detect Plasmodiophora brassicae in soils better comparing other congeneric in this study.