Detection Of Four Apple Virus And Establishment Of New Apple Cultivars Virus Elimination System

Apple virus disease has become one of major factors limiting the development of China's apple industry.At present,in the process of upgrading varieties,it is especially important for China to produce new varieties of apples to detoxify the scion and establish specialized apple seedlings for non-toxic picking.In this experiment,four apple viruses were used as the target virus,the occurrence of viral diseases in five main apple varieties were investigated,and five main apple varieties in Luochuan are: ‘GALA',‘Qinmi',‘Qincui',‘Honey crisp',‘Nagafu No.2' investigation of the occurrence of viral diseases,the occurrence of apple virus disease in Luochuan area was clarified,and the seriousness of the current production of virus-free apple seedlings was understood.‘Qinmi' and ‘Qincui' are two apple high-quality new varieties in the Northwest A&F University.This experiment mainly uses ‘Qincui' and ‘Qinmi' as test materials.Detoxification treatment was carried out,and the carrying status of seedlings was detected by RT-PCR virus detection technology in order to cultivate virus-free seedlings of two high-quality apple varieties of ‘Qincui' and ‘Qinmi',and establish a virus-free seeding garden of new apple varieties.The main findings obtained are as follows:1.RT-PCR method was used for three kinds of apple latent viruses: ACLSV,ASGV,ASPV,and a non-latent virus: ASSVd were screened,and the reaction conditions of apple rust fruit virus were optimized.2.The five main apples in Luochuan:‘GALA',‘Qinmi',‘Qincui',‘Honey crisp',‘Nagafu No.2',were conducted to investigate the occurrence of apple virus disease by RT-PCR.The results showed that the five varieties of apple trees in production were seriously infected by apple virus disease and the situation was different.The infection rates of ACLSV were 0?20%?30.4%?65.3%?10.12%,the infection rate of ASGV was 64.74%?89.64%? 91.32%?69.64%?9%,the infection rates of ASPV were 37.62%?87%? 0?75.24%?50.02%,the infection rates of ASSVd were 95.04%?60%?51%?54.14%? 53%,respectively.3.The tissue culture seedlings of 'Qincui' and 'Qinmi' were detoxified by heat treatment combined with shoot tip culture.Heat treatment combined with stem tip grafting detoxification method was used to graft the seedlings of ‘Qincui' and ‘Qinmi'.Detoxification was carried out.Studies have shown that these two detoxification methods have the effect of removing four kinds of apple viruses.Among them,ACLSV has the best removal effect,more than 90%.The removal effect of ASPV and ASGV also have obvious removal effects,and the ASSVD is difficult to remove;using these two non-viral materials production methods can effectively remove the apple virus,but the probability of obtaining completely virus-free materials is small.Detoxification conditions need to be further optimized.4.Two detoxification methods and RT-PCR virus disease detection technology provide virus-free materials for apple seedling production.