Comprehensive evaluation of wheat disease resistance and screening of excellent germplasm resources of new wheat varieties （strains）in the south of Huanghuai region

【Objective】The purpose of the study was to comprehensively evaluate the disease resistance of new wheat varieties（strains）in the south of Huanghuai region and screen excellent germplasm resources to provide a reference for disease resistance breeding and future varieties layout of wheat in the south of Huanghuai region.【Method】A total of 299 new wheat varieties（strains）summarized at all levels of tests in 2021-2022 in the south of Huanghuai region of China （unified test）were used as test materials，and the results of their disease resistance identification were evaluated，analyzed for comprehensive resistance，and screened for excellent germplasm resources with strong resistance to the disease by combining agronomic traits and quality traits.【Result】The comprehensive resistance scores of the tested varieties （strains）to stripe rust and leaf rust were 39.73 and 38.46 respectively，reaching chronic disease level. The comprehensive resistance scores to fusarium head blight，powdery mildew and sharp eyespot were 16.96，20.40 and 21.24 respectively， which were between middle susceptible and high susceptible. There were 192 varieties（strains） （64.2%）with resistance to stripe rust，182 varieties（strains） （60.9%）with resistance to leaf rust，4 varieties（strains） （1.3%）with resistance to fusarium head blight，35 varieties（strains） （11.7%）with resistance to powdery mildew，and 1 variety（strain） （0.3%） with resistance to sharp eyespot at the level of chronic disease resistance or above，but there were no varieties（strains） that were immune or near-immune to fusarium head blight and sharp eyespot. The resistance score of the tested varieties （strains）ranged from 50 to 230 with a median of 130，of which 149 varieties（strains） （49.8%）had a comprehensive resistance score higher than the median. The comprehensive resistance score of the varieties was extremely significantly negatively correlated with the effective spike number and stability time（P＜0.01，the same below），and extremely significantly positively correlated with water absorption. Phenotypic traits of disease resistant and susceptible varieties（strains） were expressed differently，with resistant varieties（strains）having lower plant height and shorter stability time. Varieties （strains）with resistance to stripe rust had higher protein content，higher wet gluten content，and higher water absorption. Varieties（strains）with resistance to leaf rust had higher yield，higher 1000-grain weight，higher test weight，and higher protein content. Varieties（strains）with better resistance to fusarium head blight had higher 1000-grain weight， higher protein content，higher wet gluten content，and higher water absorption. Varieties（strains）with resistance to powdery mildew had higher grain number per spike，higher protein content，higher wet gluten content，and higher water absorption. Varieties（strains）with resistance to sharp eyespot had higher yield，longer growth period，more effective spikes，and higher 1000-grain weight， higher test weight，and higher wet gluten content. The comprehensive resistance evaluation result screened out a total of 29 varieties（strains）with good comprehensive disease resistance and excellent yield and agronomic traits.【Conclusion】The tested varieties （strains）have better resistance to stripe rust and leaf rust，and poorer resistance to sharp eyespot，powdery mildew and fusarium head blight. Varieties with better disease resistance have higher yield，higher 1000-grain weight，higher protein content，higher water absorption，lower plant height，lower effective spike number，lower grain number per spike，lower test weight，and shorter stability time. The 29 selected varieties （strains）with excellent comprehensive performance can be used as disease-resistant gerplasm resources for future wheat disease resistance breeding.