Development Of A Rapid And Accurate Evaluation Method For Clubroot Disease

Clubroot disease is a worldwide soil-borne disease caused by Plasmodiophora brassicae,which has caused great harm to the production of Chinese cabbage.P.brassicae infects the cortical cell of the plant root and then hijack it,causing the roots form clubbed root.At present,clubroot disease has been spread widely and became serious disease worldwide.The clubroot disease evaluation is important,for pathotype classification of P.brassicae,CR cultivar breeding,and clubroot disease management.The traditional clubroot disease evaluation based on soil cultivation which was complicated in operation,labor intensive and caused environment pollution.Therefore,it is necessary to development a rapid and accurate evaluation method for clubroot disease.In this study,Chinese cabbage was planted in cultivating medium such as ceramsite,sand and perlite,which are capable for quickly cleaning of the roots.Based on the soilless cultivation,the P.brassicae inoculation methods were screened.Finally,a rapid and accurate evaluation method for clubroot root disease was developed.Finally,twelve P.brassicae isolates were inoculated to the hosts of Williams' s system for the developed evaluation method validation.Research results are as follows:1.The cultivation medium such as ceramsite,sand,perlite,centrifuge tube,cotton rope,seedling bag were used to provide nutrition for plants.The mixture of ceramsite,sand and perlite with 1:1:1 and the seedling bag method provide great growth conditions for Chinese cabbage.2.The inoculation method such as injection,root immersion method,bud immersion,P.brassicae soil and nursery bag method were screened based on the above soilless cultivation.Nursery bag and injection method shown highest incidence and disease index.3.Twelve P.brassicae isolates were inoculated to the hosts of Williams' s system for the developed clubroot evaluation method validation.There was no significant different of pathotype classification between soil and soilless cultivation method.Therefore,the developed clubroot disease evaluation method is stable and accurate.