QTLs for Pre-harvest Sprouting and Seed d Dormancy in Chinese White Wheat Landrace Tutoumai.

Pre-harvest sprouting (PHS) in rain-affected wheat is a major constraint to the production of high quality wheat, especially for those regions where white grain cultivars are preferred. Improvement of cultivar resistance is an effective solution for the problem. A population of 162 recombinant inbred lines (RILs) was developed from the cross between PHS-resistant white wheat landrace TutoumaiA and PHS-susceptible white wheat cultivar Siyang936 from China. PHS and seed dormancy were evaluated in field in Nanjing, China and greenhouse at Kansas State University, Manhattan KS, USA, respectively. After 1543 SSR primers were screened between the parents, a linkage map of 14 linkage groups was constructed with 319 polymorphic markers for the primarily QTL analysis. Six QTLs for PHS resistance and three for long seed dormancy explained up to 45.9% and 31.7% phenotypic variation, respectively, in different experiments. QTLs QPhs.Tutoumai-5B.1 and QPhs.Tutoumai-4A were significant in three of the five experiments and explained 5.0 to 12.8% and 10.4-17.6% of the phenotypic variation, respectively. The other four QTLs were detected in two of the five experiments. QSd.Tutoumai-4A was detected in all four seed dormancy (SD) experiments and explained up to 26.4% of the phenotypic variation. QSd-tutou-4B.1 was significant in two of the four experiments. All three QTLs for SD showed effects on PHS resistance. Two-locus interaction analysis detected 3 additive QTLs and two additive by additive QTL interactions for PHS and one additive QTL and one additive by additive interaction for SD. Significant genotype by environment interactions were detected for all QTLs.  Markrs for the QTLs have the potential to be used in breeding programs to improve PHS resistance for white wheat production.