Abstract
Raphanus sativus, an important cruciferous vegetable, has been increasingly affected by clubroot disease. Establishing a stable and accurate resistance identification method for screening resistant germplasms is urgently needed in radish. In this study, the influence of inoculum concentration, inoculation methods, and pH of the substrate on disease occurrence was studied. The result showed that the disease index (DI) was highest at 2 × 108 spores/mL, the efficiency of two-stage combined inoculation methods was higher than others, and pH 6.5 was favorable for the infection of P. brassicae. By using this new method, DIs of 349 radish germplasms varying from 0.00 to 97.04, presented significantly different levels of resistance. Analysis showed that 85.06% germplasms from China were susceptible to P. brassicae, whilst 28 accessions were resistant and mainly distributed in east, southwest, northwest, and south-central China. Most of the exotic germplasms were resistant. Repeated experiments verified the stability and reliability of the method and the identity of germplasm resistance. In total, 13 immune, 5 highly resistant and 21 resistant radish accessions were identified. This study provides an original clubroot-tolerance evaluation technology and valuable materials for the development of broad-spectrum resistant varieties for sustainable clubroot management in radish and other cruciferous crops.
Highlights
Clubroot disease caused by the soil-borne obligate pathogen Plasmodiophora brassicae Woronin is one of the most common and serious diseases in cruciferous crops worldwide
The Effect of the inoculation method varies in different species, as studies focusing on inoculation methods have shown that the clubroot-soil method is considered to be better than other methods in B. oleracea [84,85,86], while the dipping root method is better than the others in B. rapa [87,88,89,90]
Analysis of Variance (ANOVA) indicated that the degree of disease severity of 2 × spores/mL was significantly different from other concentrations, but there was no statistically significantly difference with 2 × and 2 × 107 spores/mL
Summary
Clubroot disease caused by the soil-borne obligate pathogen Plasmodiophora brassicae Woronin is one of the most common and serious diseases in cruciferous crops worldwide. The artificial inoculation of P. brassicae in the seedling period is mainly affected by the inoculation method, inoculum concentration, pH of seedling substrate, etc This has been reported in B. rapa and B. oleracea [83,84,85,86,87,88,89,90,91]. The Effect of the inoculation method varies in different species, as studies focusing on inoculation methods have shown that the clubroot-soil method is considered to be better than other methods in B. oleracea [84,85,86], while the dipping root method is better than the others in B. rapa [87,88,89,90]. Understanding the resistance distribution and the acquisition of diverse resistant sources will be helpful for the discovery of new clubroot resistant genes and resistance genetic improvement in radish and other cruciferous crops
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
