Phenotypic Variation of Component Traits Affecting Maturity in Cultivated Peanut (Arachis hypogaea L.)

A wide range of time-to-maturity exists among peanut accessions and cultivars, and it is a complex trait likely controlled by many genes and influenced by the environment. Underground formation of fruit coupled with indeterminate growth habit makes peanut a difficult crop species to explore genetic controls of this trait. Dividing the total phenotype of time-to-maturity into component traits can facilitate the dissection of genetic pathways controlling maturity in peanut. In this study, component traits contributing to time-to-maturity included flowering on the main stem, flowering rate, flower-to-peg conversion ratio, internode length, distribution of reproductive and vegetative nodes, branch numbers, percentage of harvestable pods, and harvest index, which were quantified for six genetically diverse peanut genotypes. Statistically significant differences were detected for all measured traits among the tested genotypes. These genotypes are parental lines of four established recombinant inbred populations. Populations with contrasting parental phenotypic values could be utilized for further QTL mapping of the relevant traits.