Marker-assisted selection and QTL mapping for yield, root morphology and agronomic traits using MASARB25 (aerobic) × Pusa Basmati 1460 F3 mapping populations

Abstract

Increasing scarcity of water has threatened the sustainability of the irrigated rice production system and hence the food security and livelihood of rice producers. Experiments were conducted to study the correlation and QTL mapping for yield, root-related and agronomic traits under aerobic conditions using MASARB25 × Pusa Basmati 1460 F3 mapping population. Yield of aerobic rice variety MASARB25 was 9-12.3% higher than Basmati rice variety Pusa Basmati 1460. MASARB25 had 9.32% higher root length, 11.76% higher fresh root weight, 19.98% higher dry root weight as compared to Pusa Basmati 1460. A total of 15 QTLs associated with 10 traits were mapped on chromosomes 2, 4, 6, 8, 9, and 11. qGY8.1 with an R2 value of 36.3% and qGY2.1 with an R2 value of 29% and qRL8.1 with an R2 value of 27.2% were identified for root length indicating the role of root traits in improving grain yield under water limited conditions. A positive correlation was found between root traits and yield under aerobic conditions. Breeding lines with higher yield per plant, root length, dry root biomass, length-breadth ratio, and with Pusa Basmati 1460-specific alleles in a homozygous or heterozygous condition at the BAD2 locus were identified that will serve as novel material for the selection of stable aerobic Basmati rice breeding lines.