Evolution of Wheat (Triticum aestivum L.) Germplasm Traits and Evaluation of Breeding Value in Southern Huang-Huai Winter Wheat Region in Recent 20 Years.

To study the evolution of wheat traits and genetic diversity in southern Huang-Huai winter wheat region, the wheat varieties in the recent 20 years in southern Huang-Huai winter wheat region were as materials. The evolution of wheat traits and genetic diversity were explored from a new perspective by using Shannon-Wiener diversity index (H') and coefficient of variation analysis, fitting trend line after dimensionless traits, principal component analysis, comprehensive score (D' value) evaluation, regression model construction and other methods. The indexes used for the evaluation of wheat varieties in southern Huang-Huai winter wheat region and the germplasm with excellent performance were screened. The results showed that a total of 443 wheat varieties were bred in southern Huang-Huai winter wheat region from 2003 to 2022, and it could be divided into 3 stages based on the number of bred varieties: basic stable stage (from 2003 to 2017), temporary high stage after obvious uplift (from 2018 to 2019, and blowout eruption stage (from 2020 to present ). In recent 20 years, plant height of wheat in southern Huang-Huai winter wheat region decreased slowly with time-going; water absorption remained unchanged; spike number, grain number per spike, 1 000-grain weight, yield, basic seedlings, test weight, protein content, wet gluten content and stability time showed upward trend, among which 1 000-grain weight, yield, basic seedlings, test weight and wet gluten content had relatively strong upward trend. The increase of yield was mainly due to the increase of 1 000-grain weight. The proportion of high-quality special wheat (strong gluten wheat, medium strong gluten wheat, weak gluten wheat) increased in recent years, mainly due to the increase in the proportion of medium strong gluten wheat. The proportion of strong gluten wheat has not increased significantly, which was mainly limited by water absorption and stability time. The dispersion degree and evolution trend of agronomic traits and quality traits were quite different, but their genetic diversity was constantly improving with the year, and genetic stability should be further strengthened. The results of regression model construction showed that 5 traits could be used as the evaluation indexes of the comprehensive performance of wheat in southern Huanghuai winter wheat region, including spike number, yield, test weight, protein content and water absorption. Among 443 varieties, 'Jimai 336' 'Anke 1801' 'Jimai 44' Gushenmai 19' and 'Huawei 305, which had higher D', performed well and could be used as excellent germplasm resources in the breeding of strong gluten wheat. In the future, the breeders should strengthen breeding new varieties with high-quality special wheat, especially weak gluten wheat, and enhance the protection and utilization of germplasm resources. [ABSTRACT FROM AUTHOR]