Xuesong Han, Yao Qin, Ada Menie Nelly Sandrine & Fazhan Qiu

Theoretical and Applied Genetics November 2020; vol. 133:3139–3150.

Key message

qKRN8, a major QTL for kernel row number in maize, was fine mapped to an interval of ~ 520 kb on chromosome 8 and the key candidate gene was identified via expression analysis.

Abstract

Kernel row number (KRN) is one of the most important yield-influencing traits and is closely associated with female inflorescence development in maize (Zea mays L.). In this study, an F_2:3 population derived from a cross between V54 (low KRN line) and Lian87 (high KRN line) was used to map quantitative trait loci (QTLs) conferring KRN in maize. We identified 12 QTLs for KRN in four environments, each explaining 1.40–14.95% of phenotypic variance. Among these, one novel major QTL (named qKRN8) was mapped to bin 8.03 in all four environments, explaining 8.79–14.95% of phenotypic variation. By combining map-based cloning with progeny testing of recombinants, we ultimately mapped qKRN8 to an ~ 520 kb genomic interval, harboring six putative candidate genes. Among them, one candidate gene showed contrasted expression level in immature ears of the near-isogenic lines qKRN8^Lian87 and qKRN8^V54. These findings should facilitate molecular breeding for KRN and the further identification of the polymorphism underlying this QTL.

See: https://link.springer.com/article/10.1007/s00122-020-03660-7