Mapping QTLs for polyphenol oxidase activity in a DH population from common wheat

Abstract

The polyphenol oxidase ( PPO) is a major factor to cause an undesirable brown discoloration of wheat-based end products during processing or storage. A double haploid (DH) population with 71 lines derived from Zhongyou 9507 with higher PPO activity and CA9632 with lower PPO activity. Field trails were conducted at three locations with two replications. A total of 173 loci included SSR, STS of storage protein and AFLP markers were used to construct a linkage map, covering 2 881 cM of whole genome at 21 linkage groups. With the method of composite interval mapping (CIM), two putative major QTLs were detected on chromosome 2AL and 2DL, accounting for 37.9%－50.0% and 25%－29.1% of the phenotypic variance across three environments, respectively. The QTL on 2AL played a more significant role than the QTL on 2DL. Reduction of PPO activity through genetic improvement and molecular marker assisted selection was also discussed.