Identification And Screening Of High-blight-resistant Potato Materials Based On The Identification Of Pathogenic Phytophthora Effector Proteins Avr3a^KI And Avr3a^EM

Late blight caused by Phytophthora infestans is a major potato disease and has been an important factor limiting sustainable potato production.The most economical and environmentally friendly strategy for the prevention and control of potato late blight is the selection and application of disease-resistant varieties.PiAvr3a^KI is the core effector protein of Phytophthora pathogen,which can be specifically recognized by the Potato Disease Resistance Gene-coding Protein R3a to stimulate the variety-specific disease resistance response.However,PiAvr3a^KI overcomes R3a-mediated varietal disease resistance by producing variant type PiAvr3a^EM evade recognition through sequence mutation.The creation and screening of potato materials that can identify PiAvr3a^KI and PiAvr3a^EM at the same time are expected to promote potato late blight resistance breeding and lay a foundation for the cultivation of highly resistant and durable late blight resistant potato varieties.In the previous laboratory resistance study on cultivars,it was found that Longpotato No.12 and Ningpotato No.18 could identify PiAvr3a^KI,and Longpotato No.7 and Longpotato No.14 could identify PiAvr3a^EM.Screening and identification of materials with high late blight resistance in potatoes from PiAvr3a^KI and PiAvr3a^EM can be identified at the same time,which provides valuable materials for potato late blight resistance breeding.Here are the research results:1.According to the laboratory analysis of the disease resistance gene composition of some late-blight resistant varieties,we designed a total of 12 hybrid combinations,including Qing 9×Ning 18,Ning 18×Long14,Qing9×Ning 20,Long12×Long7,and carried out forward and reverse crossing,a total of 220 pollination times,and obtained 47 potato fruits and more than 6000 seeds.2.Avr3a^KI and Avr3a^EM-activated cells were tested for allergic necrosis reaction of Avr3a^KI and Avr3a^EM activated cells using Agrobacterium tufacieco-mediated transient gene expression technology mediated by Agrobacterium tufacieco,and 81 materials were obtained and confirmed to identify Avr3a^KI and Avr3a^EM at the same time.The frequency of different combinations of hybrid offspring containing 2 disease resistance genes at the same time was slightly different,both of which were about 10%.3.Two portions of potato material obtained were tested for late blight resistance by indoor sterilization,and the results showed that the crossbred live seed material obtained by screening had higher late blight resistance than the parents.4.Some of the selected materials are planted at the potato breeding base in Zichang City.No diseases occurred in the field seeds,and three parts of material with good field growth were successfully screened.