Use of marker assisted selection for the introgression of quality traits from Australian into Chinese wheats

Use of marker assisted selection for the introgression of quality traits from Australian into Chinese wheats

[Abstract]Quantitative Trait Loci (QTLs) for polyphenol oxidase and xanthophyll have a significant impact on variation in wheat flour for noodle colour and colour stability. QTLs from two Australian wheat cultivars, Sunco and Tasman, have been backcrossed into two Chinese wheat varieties, Chuanmai 22 and Mianyang 11, to assess marker predictability for these important traits in significantly different genetic backgrounds. The concept of Marker-Assisted-Selection (MAS) is being trialled in this study as a proposed method for wheat improvement. In this approach molecular markers are used in conjunction with backcross breeding methods to introgress specific characters into elite breeding materials, with the goal of improving the quality attributes of wheat for the Asian noodle market. After three single seed descent generations, the backcross populations generated allow four QTLs to be investigated. These include two for polyphenol oxidase (chromosome 2A and 2D) and two for xanthophyll (chromosome 3B and 7A).

This research was successful in identifying microsatellite markers that are capable of predicting PPO activity levels and Xanthophyll content within the backcross populations. These microsatellites were validated as useful markers for these quality traits, as they have also found to be important in the Sunco x Tasman doubled haploid population. The combination of marker assisted selection and backcrossing has generated three lines that contain different combinations of the PPO activity and Xanthophyll content QTLs. These lines have been found to produce low levels of PPO activity and have a low Xanthophyll content. This improvement in flour colour and colour stability highlights the potential of marker assisted selection as a useful tool in wheat breeding.