Abstract:

【Objective】 Quantitative trait loci (QTL) for maize flower-related traits including days to tasseling (DTT), days to pollen-shedding (DTP), days to silking (DTS) and anthesis-silking interval (ASI) were mapped in two different F2:3 families with a shared male parent to provide reference for molecular breeding and related basic research in maize. 【Method】 230 and 235 F2:3 families derived from Qi 319×Huangzaosi population (Q/H) and Ye 478×Huangzaosi population (Y/H), respectively, under six different environments (2007-Beijing, 2008-Beijing, 2007-Henan, 2008-Henan, 2007-Xinjiang, and 2008-Xinjiang) were used to map QTL controlling four flower-related traits of maize by using the inclusive composite interval mapping method (ICIM). Meanwhile, QTL Network-2.0 was used to analyze epistasis among QTLs and QTL by environment interaction (QEI). 【Result】 Phenotypic analysis showed that DTT, DTP, DTS and ASI differed significantly in both Q/H and Y/H populations, while significant statistical correlations were observed between these flower-related traits in both populations. Under all of the six environments, 85 QTLs distributed on the 10 chromosomes were identified in Q/H, while 30 QTLs among which some were clustered were identified in Y/H for these four flower-related traits. Two and one important QTLs related to multiple traits were detected in each population, which were located on the interval of umc1562-bnlg1651 of Chrom. 8, phi062-umc1115 of Chrom. 10 and nc030-umc2166 of Chrom. 3, respectively. They could be expressed under different environments (may be called constitutive QTL). The results also indicated that those QTLs which could explain a relatively higher proportion of phenotypic variation seemed to control multiple target traits. Further, four QTLs were observed to be consistent between Q/H and Y/H. 【Conclusion】 Previous studies suggested that the genetic mechanisms of the flowering-related traits in maize are quite complicated. However, the results obtained here may give an important clue for precise mapping and positional cloning of QTL which could be stably expressed under different environments or genetic backgrounds.

Key words: maize')">maize, flowering-related traits, quantitative trait loci