Mapping QTLs associated with root traits using two different populations in wheat (Triticum aestivum L.)

Abstract

A well organized root system is of great importance in plants for better anchorage and efficient nutrient use. Two wheat populations were used to map QTLs associated with root traits. A double haploid population contains 216 lines and derived from a cross between Nongda 3338 and Jingdong 6. The RIL progeny includes 217 lines which were evolved from another cross between Nongda 3331 and Zang 1817. Root morphological parameters were measured in seedling stage using hydroponic culture technique. Total root length, root surface area, root volume, number of root tips and main root length were measured for both the populations. In total, 54 QTLs for root traits were detected. Among the QTLs detected, 39 QTLs distributed on chromosomes 2A, 2B, 3A, 4B, 4D, 5A, 6A, 6D, and 7B were identified in DH population, while 15 QTLs on chromosomes 1B, 2B, 3B, 4A, 4D, 5A, 5B and 7A were identified in the RIL population. QTLs were clustered in 8 genomic regions in DH and 4 genomic regions in RIL population. Important QTL rich regions on chromosome 2A (wsnp_Ex_c19516_28480622-Xgwm614b), 3A (Excalibur_c24354_465-Kukri_rep_c102151_697 and Xwmc695-IAAV5821) and 4D (RAC875_c5827_554-wsnp_BF473052D_Ta_2_1) in DH and 3B (Xbarc115-Xwmc291), 4A (Xcwem34-Xbarc28b) and 4D (Xbarc1118-Rht2) in RIL population were found as they had pleiotropic effect for controlling root traits. Negative correlation was found between root traits and plant height in both populations. Root traits was found unaffected by Rht2 gene. Major QTLs detected on chromosome 4D for root traits might be different from the QTL detected previously for plant height.