An Investigation Of Factors Limiting Sustainable Potato Production In Ningxia And Population Analysis Of Phytophthora Infestans

Potato is one of the pillar food crop industries in Ningxia,and its sustainable production is of great significance to regional food security and farmers’ income.In this research,we focused on the potato production in Ningxia and its limiting factors by investigating and surveying published statistical data and literatures.Aiming at the effective control of the most serious potato disease in the region,late blight caused by Phytophthora infestans,we investigated population genetic analysis and examined for genetic diversity,source of variation,and sexual reproduction of P.infestans populations,and source of primary infection crucial for late blight development.The main results are as follows:1.Over last five(or 10)years,the potato production acreage is decreasing while the yield level is steadily increasing in Ningxia.Late blight is the most serious potato disease in the south Ningxia,the main potato production region,which is frequent and the limiting factor.This,together with the potato production practices in developed regions and countries,suggests that production and certification of high-quality potato seed tubers will be critical for late blight management and sustainable potato production.2.A total of 174 isolates of P.infestans were obtained in Ningxia in 2020 and characterized for level and source of genetic variation using biological and molecular population genetics methods,including mating type distribution,9 SSR markers.The results showed that the A2 mating type was dominant(97.70%).3.Characterization of P.infestans populations using 9 SSR markers showed that the population genetic diversity in Ningxia was high(H = 4.95),with 153 SSR genotypes identified from 170 isolates.However,the genetic variation was mainly within the population(82.00%).Multi-locus linkage disequilibrium analysis showed that the P.infestans populations in Ningxia were asexual.Taking into account the geographical and climatic conditions in south Ningxia and the potato production practice in the region where farmers frequently used self-reserved seed tubers,we propose that the quality of seed tubers remained an important initial infection source of late blight.Therefore,the certified seed tuber production,strict certification of seed tubers,and fungicide treatment of seed tubers will be effective in controlling late blight and supporting sustainable potato production in the region.