Utilization of wheat 55K SNP array for QTL mapping of plant height and flag leaf in a RIL population

Abstract

Plant height (PH) and flag leaf (FL) are two crucial agronomic traits for crop yield. A recombinant inbred line (RIL) population from ‘Mian 96-5’ (M96-5) and ‘Guixie 3’ (GX3) was investigated in five environments to study PH and FL characteristics in Chinese southwest wheat. Eight QTLs related to PH were detected on five chromosomes 1D (1), 2D (1), 4B (2), 4D (2), and 5A (2). Of these, Qph.gaas.2D explained phenotypic variance (PVE) of 22.40%, Qph.gaas.4B.1 (PVE = 21.92%), Qph.gaas.4D.1 (PVE = 12.29%), and Qph.gaas.4D.2 (PVE = 13.69%), which were consistent with known Rht8, Rht-B1, and Rht-D1 loci, respectively. The other four QTLs about PH, namely Qph.gaas.1D (212.50–258.36 Mb), Qph.gaas.4B.2 (643.50–646.67 Mb), Qph.gaas.5A.1 (515.06–523.07 Mb), and Qph.gaas.5A.2 (523.07–528.26 Mb), were novel QTLs for reduced wheat PH. Five, four, and five QTLs were related to length, width, and area of flag leaf. Among them, a major QTL (Qfll.gaas.2D, 15.79 ~ 37.04 Mb) was detected on chromosome 2D, where six candidate genes related to the photo-respiration stage of photosynthesis were found. Two important regions on chromosome 4B (25.83 ~ 29.20 Mb and 32.96 ~ 35.63 Mb) were related to the length, width and area of flag leaf at multi-environments, and including genes related to programmed cell death and metabolic regulation of gibberellin in the wheat grain-filling stages. These QTLs would be useful in further studies for decreasing plant height, providing theoretical support for the improvement of wheat plant type and boosting grain yield through pyramiding breeding.