engleski

QTL analysis of maize ear inflorescence in a fasciation contrasting inbreeds cross PB260 x PB266

Maize ear inflorescence architecture is intrinsically important to grain yield components. Thus a thorough knowledge of the genes affecting ear inflorescence architecture and their interactions may lead to better yield modelling. Maize ear fasciation, characterized by abnormal flatten ears with higher kernel row number, is widely present in Portuguese maize landraces showing quantitative variation. To elucidate the genetic basis of ear inflorescence architecture traits related with fasciation, F2:3 families were developed from a fasciation contrasting cross (PB260-nofasciation x PB266-fasciation). F3 lines were evaluated for 28 ear architecture traits plus yield, in two Portuguese environments (Calderao and Montemor-o-Velho). Highly significant correlations were found between fasciation and other traits. Fasciation broad-sense heritability was 0.73. Principal Component Analysis was performed to isolate the factors that defined overall variation in maize ear architecture. First three principal components accounted for 71 to 73% of variation. In order to map quantitative trait loci (QTL) for these traits, a genetic linkage map was constructed in F2 population. Overall, 64, QTLs for individual ear architecture traits (38 in Montemor and 26 in Calderao), explaining individually 10.7 to 22.4% of the phenotypic variance, were detected. 12 QTLs were conserved through environments. This analysis provided initial insight into the genetic basis of quantitative variation of fasciation related ear architecture traits. Future studies should focus on fine mapping of the identified genome regions.

Zea mays; fasciation; ear architecture; landraces; genetic mapping; QTLs

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