Mapping QTLs for important agronomic traits in an Iniadi-derived immortal population of pearl millet

Abstract

Pearl millet [Pennisetum glaucum (L.) R. Br.] is a climate-hardy nutricereal and an essential staple for the people living in dry regions. Substantial improvement has been achieved for seed yield stability in pearl millet, the cultivable area under pearl millet reduces. Deployment of early-flowering, bold-seeded and dwarf genotypes in pearl millet is a vital breeding strategy to improve grain production and enhance the adaptability of pearl millet in low-input farms. Therefore, an experiment was performed for mapping agronomically important traits like flowering time (FT), plant height (PH), panicle length (PL), and 1000-grain weight (TGW) in 317 recombinant inbred line (RIL) population derived from ICMS 8511-S1-17-2-1-1-B-P03 × AIMP 92901-S1-183-2-2-B-08 cross. Broad-sense heritability estimates were high to very high, ranging from 0.52 (PL) to 0.86 (PH). FT showed a significant positive correlation with PH. A key QTL for FT was mapped on LG 1, 15 QTLs for PH scattered on 10 chromosomes, five QTLs for PL dispersed on four chromosomes, and two QTLs for TGW spanned linkage groups 3 and 7. One QTL on LG1 was common for FT and PH. Two major QTLs for PH, one each on LG4B/8 cM and LG7/110 cM were detected. The large effect QTL for TGW on LG7 had a phenotypic variance (R²) of 24.3%. The R² for PH and PL ranged between 5.2 - 24.5% and 5.0–11.5%, respectively. The QTLs mapped for FT and other agronomic traits in the current study can be exploited to develop elite hybrid parental genotypes/cultivars through marker-assisted breeding and genomic selection.