Kernel weight in maize: Genetic control of its physiological and compositional determinants in a dent × flint-caribbean RIL population.

MANDOLINO, C.; D'ANDREA, K.E.; PIEDRA, C.V.; ALVAREZ PRADO, S.; OLMOS, S.; CIRILO, A.G.; OTEGUI, M.E.

MAYDICA

MAYDICA-IST SPER CEREALICOLTUR

Lugar: Bergamo; Año: 2016 vol. 61 p. 1 - 13

0025-6153

The genetic control of maize kernel weight (KW) determination could be studied through its physiological and/or compositional determinants. Our objective was to dissect the genetic control of maize KW by analyzing itsphysiological (KGR: kernel growth rate; KFD: kernel filling duration) and compositional (protein, oil, starch) determinantsin a dent×flint Caribbean RIL population, which combines a broad genetic background with grains ofhigh added value for industry. An additional objective was to determine the stability of the genetic control undercontrasting growing conditions, for which soil nitrogen offer was modified across experiments. Heritability (H2)values were high for KW (H2 = 0.74) and intermediate for the other traits (from 0.62 to 0.42). Kernel weight hada strong correlation with KFD (r = 0.69), KGR (r = 0.60) and protein concentration (r = 0.56). Ten joint QTL withinconsistent effects across years and seven epistatic interactions were detected. Despite changes in effect size,most QTL were significant under both environments. Nine QTL were associated with variations in potential KW(KWP), mean KW, KGR and oil concentration, eight with variations in protein and starch concentration and sevenwith KFD. Epistatic interactions were related to regions with significant main effects. The most important findingwas the existence of a common QTL for KWP, KGR and KFD on chromosome 5, for which there was no previousreport. Results increased our knowledge on the genetic control of KW through its phenotypic and genetic correlationwith KFD, confirming the need to explore different physiological strategies in different genetic backgrounds.