Evaluation of qDTY QTL introgressed rice genotypes for yield under drought stress across environments

Rice production is severely hampered by drought stress, especially during reproductive stage, which causes enormous yield losses. Present study screened 120 backcross inbred lines (BILs) which harbours three qDTY QTLs (qDTY1.1, qDTY3.1 (Apo) and qDTY12.1 (Wayrarem)) combinations along with three parents ADT(R) 45, Apo and Wayrarem under managed water stress conditions. Best performing 21 BILs were evaluated for its stable yield performance under four different environments. AMMI and GGE biplot analysis revealed that five BILs, viz., W 47, W 18-8-7, I 85, I 127 and I 172, having qDTY 12.1 either alone or in combination with other qDTY QTLs were found to be highly stable with higher yield across the environments. This result implied that greater interaction of qDTY_12.1 with the genotypes for their stable performance across the environments than other two qDTY QTLs is observed. Intensive root phenotyping of these BILs through basket method identified that BILs, such as I 127 and I 85, were possessed maximum root numbers, root thickness coupled with deep rooting. Thus, the genotypes harbouring qDTY12.1 could be released as potential varieties and utilized in future breeding programmes to improve the yield under drought stress in rice.