Construction And Initial Identification Of Physiological Race Library Of Magnaporthe Oryzea In South-west Hubei Province

Rice blast, caused by the ascomycete fungus Magnaporthe oryzae, is one the mostdevastating diseases of this crop worldwide. Breeding and utilization of resistant varieties isstill the most effective, economical and environment-friendly way to control the disease.While M. oryzae is known for its complex population structure and high variability in fieldconditions, which causes frequent loss of host resistance. Therefore, analysis the geneticstructure and variation of M. Oryzae can provide an important basis for the prediction andforecasting of disease and the layout of resistant varieties, which can effectively preventdisease epidemic caused by loss of host resistance.The Wuling mountainous area has special ecological conditions and is marked as thedisaster area of rice blast. In this study, M. Oryzea infected rice straws were collected fromSouth-West Hubei Province, belonging to the Wuling mountainous area, to construct thephysiological race library. Based on the analysis of the genetic structure differences, we hopeto provide a basis for predicting the trend of changes in M. Oryzea population and breedingnew resistant varieties for local region. The main results are as follows:1. In total,82strains were isolated from infected rice straws, which were collected from7rice main production region of South-West Hubei Province. By comparison of sporulationusing6different culture mediums, the additional juice of preserved plum can effectivelyenhance the sporulation of M. Oryzea.82initially isolated strains were identified by checkingwhether it can generate typical pear shaped single pore or not. The52strains are consideredas typical M. Oryzea strains. The other30strains cannot generate typical pear shaped singlepore, which are removed from the following research.2.52identified isolates were divided into3categories, according to the color differenceof colony after5-days and10-days culture, respectively. Cluster analysis of34representativeisolates was conducted by RAPD and REMAP.34strains could be divided into6lineagesaccording to their genetic differences.3. The information of collection source, morphological classification and molecularfingerprint was registered and all the52isolates were kept in-80℃freezer. Thus, aphysiological race library of M. Oryzea, which is including52isolates from South-WestHubei Province, was preliminarily constructed.