Genetic mapping of the gene affecting polyphenol oxidase activity in tetraploid durum wheat
The quality of durum wheat (Triticum turgidum ssp. durum) is influenced by polyphenol oxidase (PPO) activity and its corresponding substrates. A saturated molecular-marker linkage map was constructed previously by using a set of recombinant inbred (RI) lines, derived from a cross between durum wheat cultivars Jennah Khetifa and Cham 1. Quantitative trait loci (QTL) for PPO activity in seeds were mapped in this population. PPO activity in seeds of the parents and 110 RI lines was measured spectrophotometrically. The PPO activity of Cham 1 was significantly lower than that of Jennah Khetifa. QTL analysis of these data indicated that most of PPO activity was associated with major loci on the long arm of chromosome 2A. The trait was found to be strongly associated with the SSR marker Xgwm312@2A. With this knowledge, marker-assisted selection can be used to select genotypes with lower PPO activity in durum wheat populations.
N. Watanabe, Ibaraki University, College of Agriculture, 3?21?1 Chuo, Ami, Inashiki, Ibaraki 300?0393, Japan