Analysis of Genetic Diversity and Trapping Elite Alleles for Plant Height in Drought-Tolerant Wheat Cultivars

Abstract

Plant height (PH) reduction has obviously contributed to lodging resistance and yield increase of wheat ( Triticum aestivum L.) in the last decades. The objectives of this study were to understand the diversity status of wheat cultivars in northern China and to identify simple sequence repeat (SSR) markers associated with PH. Using 117 SSR markers evenly distributed on wheat chromosomes, a total of 1484 alleles were detected in 136 winter wheat cultivars that were historically planted in northern China. The average allele number per locus ranged from 2 to 42 with an average of 12.6. The polymorphism information content (PIC) values ranged from 0.016 to 0.941 with an average of 0.640. Based on the cluster tree, the cultivars developed by the same breeders or kin cultivars were gathered in the same subgroup. Some cultivars with similar ecotypes or developed contemporaneously also fell into the same subgroup. Nineteen SSRs each were significantly associated with PH under drought and well-watered conditions, respectively ( P < 0.01), including 9 common markers, viz., Xbarc125 (7D), Xbarc168 (2D), Xgwm126 (5A), Xgwm130 (2B), Xgwm212 (5D), Xgwm285 (3B), Xgwm495 (4B), Xgwm95 (2A), and Xwmc396 (7B). The alleles of Xgwm285-220, Xgwm495-181, Xbarc125-167, and Xgwm212-99 were elite alleles for reducing PH.