The Pathogenicity Differentiation Of Plasmodiophora Brassicae At Different Families And Different Generas Of Cruciferae Levels And Establishment Of Physiological Race Single-spore System

Clubroot disease of cruciferous crops is a root disease caused by Plasmodiophora brassicae Woronin.The host range of P.brassicae was very wide,it not only parasitic cruciferous plants,but also infected non-cruciferous plants when inoculated.P.brassicae has parasitic specialization,and its physiological races have been extensively studied.However,whether there are varieties and forma specialis of P.brassicae that has not been identified at home and abroad.So far,in addition to the previous studies of the project group,there has been no literature report that the pathogenicity differentiation of P.brassicae at different families and different generas of Cruciferae levels.In this study,we continue to explored the pathogenicity differentiation of P.brassicae at different families and different generas of Cruciferae levels,and then optimized the method of single spore inoculation and cultivated of inoculation plant,in the last,established a single-spore system.The results of the study as follows:1.The pathogenicity differentiation of P.brassicae at different Families levelsCollecting different families host which are reported at home and abroad,11 Families,13 Genus,and 13 Species;according to the near source of these 11 Families,selecting new non-crucifer plants,8 Families,9 Genus,9 Species;10 regions of the clubroot materials in this country have been collected;The pathogenicity differentiation of P.brassicae at different families levels was obtained through the laboratory inoculation test.It was showed that the pathogenicity were different among P.brassicae.Observing under the microscope,Inoculating resting spores for 10 d,hair infections of all the plants has been observed.Inoculating resting spores for 20 d,there are only Tropaeolum majus,Capsicum annuum,Ipomoea aquatica,Brassica juncea var.tumida occured cortical infection.In the plants of different families,only Tropaeolum majus,Brassica juncea var.Tumida,Capsicum annuum,Ipomoea aquatica were found to be infected by P.brassicae,and no clubbed the other families of plants were found.According to the pathogenicity differentiation of P.brassicae at different families levels,the P.brassicae were preliminarily divided into 4 varieties: P.brassicae Woronin var.cruciferous,P.brassicae Woronin var.eggplant,P.brassicae Woronin var.convolvula,P.brassicae Woronin var.capucine.2.The pathogenicity differentiation of P.brassicae at different generas of Cruciferae levelsCollecting different genera of the family Cruciferae which have been reported at home and abroad,28 Genas,30 Specie,33 Varieties;10 regions of the clubroot materials in this country have been collected;The pathogenicity differentiation of P.brassicae at different generas of Cruciferae levels was obtained through the laboratory inoculation test.It was showed that the pathogenicity were different among clubroot materials.This indicated that pathogenicity differentiation P.brassicae existed at different generas of Cruciferae levels.Sinapis alba,Erucas ativ,Capsella bursapastoris,Isatis tinctoria,Arabidopsis thaliana,Malcolmia africana,Cheiranthus alliohii,Wasabia japonica,Brassica oleracea L.Erysimum bungei were found to be infected by P.brassicae,Lobularia maritima,Raphanus sativus L.Lepidium sativum,Brassica oleracea L,Armoracia rusticana,Hesperis matronalis,Orychophragmus violaceu,Iberis amara were found have resistance differences,No clubbed Aubrieta cultorum,Matthiola incana,Descurainia sophia,Brassica oleracea var.Acephala,Nasturtium officinale,Cheiranthus cheiri were found.According to the pathogenicity differentiation of P.brassicae at different generas of Cruciferae levels,the P.brassicae were divided into 4 Forma specialis:P.brassicae Woronin f.sp.radicula,P.brassicae Woronin f.sp.brassica,P.brassicae Woronin f.sp.hesperis,P.brassicae Woronin f.sp.orychophragmus.3.Establishment of P.brassicae single-spore systemUsing 3 different physiological race identified by the Williams system,Through the improvement of the method of single spore inoculation and cultivated of inoculation,36single-spore tumors of 3 physiological race are acquired;with three times propagation of one of these single spore tumors,301 root tumors were finally achieved,successfully forming a single-spore system.