GENETIC EVOLUTION AND UTILIZATION OF WHEAT GERMPLASM RESOURCES IN HUANGHUAI WINTER WHEAT REGION OF CHINA

Abstract

To determine the genetic variation of wheat germplasm resources and improve their use in wheat breeding, 215 wheat cultivars and advanced lines from the Huanghuai Wheat Region of China were used to identify 14 agronomic traits and 7 quality traits, as well as the evolution and utilization of high molecular weight glutenin subunits (HMW-GS) and low molecular weight-glutenin subunits (LMW-GS). From landrace cultivars to current cultivars there had been significant increases in grain numbers spike-1, grain weight spike-1, 1000-kernel weight, grain weight plant-1, spikelet number spike-1, sterile spikelet numbers spike-1, flag leaf width, and flag leaf area. There had been significant decreases in spike number plant-1, plant height, the first internode length, flag leaf length, kernel protein content and wet gluten content. Based on Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results, a novel HMW-GS combination 20/8 was identified in 1B chromosome of Chinese landrace cultivar Heputou. Subunits 22, 20/8, 2.2+12, and GluB3a were only found in cultivars before the 1960s, and subunits 6+8, 13+16, 3+12, and 4+12 were only found in the cultivars after the 1980s. The average diversity index of 21 traits and allele variance of HMW-GS showed a decreasing-increasing-decreasing tendency. HMW-GS and LMW-GS combination-type cultivars showed an increasing-decreasing tendency. Before the 1980s, most parental strains were from foreign cultivars and landrace cultivars, while after the 1980s, most parental strains were from released cultivars and germplasm created by distant hybridization. This study provided useful information for improvement of wheat breeding in Huanghuai winter wheat region.