Abstract:
Determining how to choose parents and conduct selections is a critical issue in plant breeding. The genetic and breeding simulation tool QuCim can predict the outcome of a cross under a specific selection scheme, when genetic information for the targetted traits is known. In this paper, we use genetic information from Australian wheat breeding programs about glutenin, as it relates to wheat quality, to predict the outcomes from some example crosses. The 8 Silverstar sister lines used in our study are morphologically very similar, but have different values for 2 important quality traits, maximum dough resistance (Rmax) and extensibility. Supposing we intend to use Silverstar in crosses with other adapted cultivars, without losing grain quality, which sister line should we use? Under the condition that high Rmax is the major breeding objective, QuCim simulation showed that Silverstar 3 and 7 should be chosen if the other parent does not have allele b at Glu-A3 and allele d at Glu-D1. If the other parent has allele b at Glu-A3 and allele d at Glu-D1, all 8 lines can be used. If the other parent does not have allele b at Glu-A3, but has allele d at Glu-D1, Silverstar 3, 4, 7, and 8 should be used, and if the other parent has allele b at Glu-A3, but does not have allele d at Glu-D1, Silverstar 1, 3, 5, and 7 should be used. Therefore, the optimum Silverstar line depends on the alleles present at glutenin loci in the other parent. Australian wheat cultivars Krichauff and Machete have a similar value for Rmax, but they differ substantially as a donor for improving Rmax in other parents. For crosses with Australian wheat cultivar Trident, Machete is the better choice, but for crosses with the Australian wheat cultivar Westonia, Krichauff is better. In conclusion, QuCim can accurately predict the outcome from a specific cross under a selection scheme when gene information is known. It can help breeders identify the best crosses and selection methods to achieve their breeding objectives.