A New Identification Method Reveals the Resistance of an Extensive-Source Radish Collection to Plasmodiophora brassicae Race 4

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, pH substrate on disease occurrence was studied. The result showed that index (DI) highest at 2 × 108 spores/mL, efficiency two-stage combined methods higher than others, 6.5 favorable infection P. brassicae. By using new method, DIs 349 radish varying from 0.00 to 97.04, presented significantly different levels resistance. Analysis 85.06% China were susceptible brassicae, whilst 28 accessions mainly distributed east, southwest, northwest, south-central China. Most exotic resistant. Repeated experiments verified stability reliability identity germplasm total, 13 immune, 5 highly 21 identified. This study provides original clubroot-tolerance evaluation technology valuable materials development broad-spectrum varieties sustainable management other crops.