Influence of Mating Structure on Agronomic Performance, Chip Fry Color, and Genetic Distance Among Biparental Tetraploid Families

The impact of mating structure on progeny performance is not routinely analyzed in potato breeding programs, despite the importance of choosing parental lines. Varying degrees of assortative and disassortative mating can have a significant effect on the agronomic performance and cold chipping ability of potato breeding clones. A disassortative mating strategy of crossing parents from different market types can incorporate commercially relevant traits into a market class which lacked that trait. Here we report the effect of mating structure in three breeding families created from parental lines from different market classes, within the same market class, and from self-pollination. Disassortative mating structure produced clones with increased yield and tuber size while assortative mating produced clones with improved cold-storage chipping ability. Inbreeding depression was observed for yield, tuber traits, and chip color in the selfed progeny. Chip color in a russet type clone was improved through crossing with an elite chipping parent, demonstrating a viable method for improving russet processing quality. Mating structure explained a significant proportion of phenotypic variance for yield, tuber, and chipping traits across the three families. Discriminant analysis of principal components and genetic distance based on SNP markers from the SolCAP project were able to discriminate among family types and were informative about the relative diversity generated from each particular cross. A number of promising genotypes from both the russet x chipper family and the chipper x chipper families were identified which outperformed parental varieties for chip color and tuber size.