Developing genetic resources and genetic analysis of plant architecture-related traits in teosinte-introgressed maize populations

Abstract

Teosinte, the wild progenitor of maize, has immense potential for providing unique traits and is more divergent compared to inbred lines and landraces. One hundred and sixty-nine teosinte-introgressed maize backcross inbred lines were developed to widen the genetic base of maize with predomestication alleles. The population was evaluated phenotypically and genotypic data of 76 SSR markers were used to map quantitative trait loci (QTLs) governing the targeted traits. Sixty-six QTLs were detected for eight plant architect-related traits that are spread over 10 different chromosomes with phenotypic variation ranging from 2.29 to 13.97%. Maximum three stable QTLs were recorded for days to anthesis (DA) followed by two for days to silking (DS), plant height (PH) and node bearing first ear (NBE). For rest of three traits namely flag leaf length (FLL), flag leaf width (FLW) and ears per plant (E/P) only one stable QTL was detected. Among the 16 common QTLs, the marker phi328178-linked QTL governed four characters (DA, DS, FLL, FLW) simultaneously, followed by umc1622-linked (ASI, FLW, E/P), umc2341-linked (DA, DS, NBE) and phi075-linked QTLs (ASI, PH, NBE) controlling three traits each. Remaining 12 QTLs controlled two characters. Molecular association between co-localized QTLs for different traits was also validated at the phenotypic level by significant correlation estimates. For eight studied traits, 53 superior lines were identified which along with parents (teosinte and maize inbred DI-103) were grouped into 12 clusters. Therefore, lines clustered independently can be combined to accumulate desirable traits for the improvement of maize.