Abstract

Sonu Bharti, H. S. Balyan and P.K. Gupta

In India, large areas of wheat cultivation suffer with water-stress leading to poor yield, which may be improved through genetic manipulation of plant architecture, particularly involving the root morphology. The root system plays a key role in water and nutrient absorption from the soil, but has not received due attention of geneticists in the past due to the difficulties associated with phenotyping of this trait. During the present study, we dissected the genetic architecture of four root traits through QTL analysis using a RIL mapping population derived from the cross Chinese Spring × Rye Selection. Eight QTLs located on six chromosomes were identified, which included two suggestive QTLs (one each for root length and root dry weight), and six significant QTLs, which included one QTL for root number, four QTLs for root volume and one QTL for root dry weight. A major QTL (QRv.ccsu-4A.1) for root volume, detected at a LOD score of 6.5, explained ~30% phenotypic variation in root volume. The remaining five minor QTL each explained 8.82% (QRv.ccsu-2D.1 for root volume) to 15.93% (QRdw.ccsu-2A.1 for root dry weight) of the phenotypic variation. SSR markers Xgwm89 and Xgwm610 flanking the major QTL QRv.ccsu-4A.1 may be used for marker-assisted selection for higher root volume for improvement of water absorption efficiency of wheat grown in limited-water conditions.