QTL detection for grain yield and micro-nutrition contents in rice (

Context Enhancing grain yield and micro-nutrition contents in rice (Oryza sativa L.) through biofortification breeding is an efficient way to address micro-nutrient deficiencies in human. Aims QTL mapping for grain yield and micro-nutritional traits is prerequisite for developing new rice varieties. Methods QTLs for grain yield and micro-nutritional traits were identified using a backcross inbred lines (BIL) derived from an interspecific backcross of Xieqingzao B and Dongxiang wild rice (Oryza rufipogon Griff.). Key results A total of 16 and 29 QTLs were identified for grain Zn, Mn and Cu contents, including three for brown and milled rice, 10 for brown rice only, and three for milled rice only, and for grain related traits, respectively. Among grain micro-nutrient QTLs, three QTLs, qMn4, qMn6.2 and qZn6.2, showed genetic effects on both brown and milled rice. Conclusion Sixteen QTLs for grain related traits and eight QTLs for grain micro-nutrient content had O. rufipogon favourable alleles. A total 31 QTLs were clustered eight chromosomal regions. Importantly, two clusters, qZn4/qGW4 and qZn6.2/qMn6.2/qCu6.3/qGYP6.2, had the favourable wild alleles, suggesting that O. rufipogon alleles had synergistic effects on both yield component and micro-nutrient content. Implications These candidate QTLs could be useful for the improvement of grain yield and micro-nutrients through QTL pyramiding.