Molecular Identification And Disease Resistance To Apricot Chlorotic Leaf Roll Phytoplasma In Xinjiang

Apricot chlorotic leafroll(ACLR)is a phytoplasma disease harming apricot trees.Because there are few reports about the disease in China,this study combines field investigation with molecular detection results,and analyses the resistance of Different Apricot Varieties to chlorotic leaf roll disease of apricot.The results are as follows:(1)The comprehensive comparison of field survey and test results showed that the incidence and disease index of each collection site were different.Among them,the national fruit tree resources in Luntai County had the most serious disease incidence,the incidence rate reached 63.2%,and the disease index reached 17.3.Diferent apricot varieties have different resistance/pat-hogenicity,and are affected by a series of factors such as season,climate,management mode and tree age,and show certain regularity.Further detection of pathogens caused by phytoplasmas by molecular detection.(2)Molecular identification results showed that the Xinjiang isolate of apricot chlorotic leaf roll phytoplasma belonged to 16Sr V group.Simulated digestion maps are different from all established reference models of 16Sr V subgroup.Among them,there is the highest similarity with members of 16SrV-B subgroup,but there are differences in individual digestion sites.The similarity coefficient is 0.94.Therefore,it is speculated that the apricot chlorotic leaf roll may be a new subgroup of 16SrV subgroup.(3)The standard curve made in this study has a good linear relationship,and real-time fluorescence quantitative PCR with TaqMan probe can detect 280 copies of plasmid DNA.The established real-time fluorescence quantitative PCR with TaqMan probe has good specificity,sensitivity and amplification efficiency.It can detect the apricot chlorotic leaf roll rapidly and quantify the content of chlorotic leaf roll phytoplasma of Xinjiang apricot at the quantitative level of pathogen.(4)The resistance/susceptibility of different apricot varieties to chlorotic leaf roll disease of apricot showed that there were some differences in resistance/susceptibility of different apricot varieties.At present,12 apricot varieties are preliminarily speculated to be "disease-tolerant varieties",9 apricot varieties are" susceptible varieties",and 9 apricot varieties need further detection and determination of the difference in resistance/susceptibility.The content of chlorotic roll-leaf phytoplasma of apricot varies in different seasons,and its mechanism needs further study.In this study,the classification status of Xinjiang isolates of apricot chlorotic leaf roll phytoplasma was clarified at the subgroup level through sequence analysis and RFLP analysis of three different genes.By establishing quantitative detection technology system and evaluating disease resistance of Different Apricot varieties,it is helpful to prevent the outbreak and malignant spread of ACLR disease and promote the healthy and sustainable development of forest and fruit industry in Xinjiang.It is of great significance to prevent the outbreak and malignant spread of ACLR disease and to promote the healthy and sustainable development of forest and fruit industry in Xinjiang.