BSA-seq-based identification of a major additive plant height QTL with an effect equivalent to that of Semi-dwarf 1 in a large rice F-2 population

Bulked-segregant analysis is a time- and cost-saving strategy for identifying major quantitative trait loci (QTL) in a mapping population. Bulked-segregant analysis combined with whole-genome sequencing (BSA-seq) was performed to rapidly identify QTL for heading date, plant height, and panicle length in a large F-2 population derived from two landraces: Chuan 7 (C7) and Haoboka (HBK). Twenty plants with extremely low or high phenotypic values for the target traits were selected from an F-2 population of 940 plants to construct low- and high-value bulks. Three pairs of bulks for the three traits were constructed, resulting in six DNA pools. BSA-seq revealed nine QTL: four for heading date, three for plant height, and two for panicle length. These QTL were validated in a random F-2 population or BC4F2 populations. The major novel plant height QTL, qPH8, acting additively with an effect equivalent to that of semi-dwarf 1 (sd1), is potentially valuable for hybrid rice breeding. qPH8 controls mainly the elongation of basal internodes. The C7 allele of qPH8 reduces plant height and increases lodging resistance without yield penalty, suggesting a potential role for qPH8 in improving rice plant architecture. (C) 2021 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.