Molecular mapping of quantitative trait loci for grain moisture at harvest in maize.

In maize, high grain moisture ( GM) at harvest causes problems in harvesting, threshing, artificial drying, storage, transportation and processing. Understanding the genetic basis of GM will be useful for breeding low- GM varieties. A quantitative genetics approach was used to identify quantitative trait loci ( QTL) related to GM at harvest in field-grown maize. The GM of a double haploid population consisting of 240 lines derived from Xianyu335 was evaluated in three planting seasons and a high-density genetic linkage map covering 1546.4 cM was constructed. The broad-sense heritability of GM at harvest was 71.0%. Using composite interval mapping, six QTL for GM at harvest were identified on five chromosomes (Chr). Two QTL located on Chr1, qgm1-1 and qgm1-2, explained 5.0% and 10.8% of the phenotypic variation in GM at harvest, respectively. The QTL qgm2, qgm3, qgm4 and qgm5 accounted for 3.3%, 8.3%, 5.4% and 11.0% of the mean phenotypic variation, respectively. Because of their consistent detection over multiple planting seasons, the detected QTL appear to be robust and reliable for the breeding of low- GM varieties. [ABSTRACT FROM AUTHOR]