Drought resistance of wheat alien chromosome addition lines evaluated by membership function value based on multiple traits and drought resistance index of grain yield

Abstract

Drought is the single greatest abiotic stress leading to yield loss of wheat worldwide. The long-term domestication and selective breeding in artificial environments may have reduced the drought resistance of wheat. Wheat alien chromosome addition lines, with chromosomes derived from wild species, may possess drought resistant genetic potential and could serve as a bridge for transferring those traits to wheat. The drought resistance of 82 wheat alien chromosome addition lines along with their common parent Chinese Spring were evaluated for 10 agronomic traits under both well-watered and water-stressed conditions. Spike length was the most stable trait while biomass plant−1 was the most sensitive trait when subjected to drought stress. Evaluation of heritability and correlations with yield plant−1 suggested that plant height, peduncle length, distance between spike and flag leaf, grain number spike−1 and thousand-grain weight could be used as indicators of drought resistance. The membership function value of drought resistance (MFVD) based on those traits and grain yield plant−1, indicated 26 of the 82 wheat addition lines expressed high drought resistance. Higher MFVD was observed in the Agropyron elongatum 3E addition line in two years, and it was considered as the most drought resistant material. Analysis of the yield plant−1 suggested that the drought resistant addition lines identified by MFVD were drought resistant but not very high-yielding, thus they could be used to improve germplasm with high-yield potential but low drought resistance. The drought resistance index (DI) based on yield plant−1 indicated that 10 addition lines included both drought resistance and greater grain yield, which could be used in moderate stressed areas for improving drought resistance. Among them, addition lines with Aegilops peregrina 4SV and Ae. peregrina 3UV chromosome showed excellent performance and could be further investigated in drought resistance studies or breeding programs.