Quantitative Trait Loci (QTLs) Mapping of Root Traits in Four Different Doubled Haploid Mapping Populations of Bread Wheat (Triticum aestivum L.)

The genetics of root system is still not dissected for wheat and lack of knowledge prohibits the use of marker assisted selection in breeding. Doubled haploid bi-parental mapping populations are well known and practical solutions for genetic maps. The Synthetic W7984 X Opata M85 bi-parental doubled-haploid mapping population (SynOpDH) was evaluated for mature root biomass, and three newly generated doubled haploid populations by the pair-wise crossing of three landrace cultivars (Cv. Sonora, cvs. Foisy (F) and Chiddam Blanc de Mars (CBdeM)) were evaluated for seedling root angle and number traits. All populations showed significant phenotypic variation for all traits and each demonstrated transgressive segregation. Major QTL for total root biomass on SynOpDH population were detected on homoeologous chromosomes 2A and 2D with LOD scores between 6.25 and 20.86. A QTL on 2DS appeared in two of the three pair-wise populations. One QTL for seminal root number was identified on chromosome 4BL. The QTLs for root biomass and angle addressed chromosome 2D. There is a high possibility of a conserved region on chromosome 2D for root system traits.