Use of quantitative serology in predicting the genotypic relationships of oat cultivars

Summary Quantitative serological techniques were used to estimate the genotype relationships of six oat (Avena sativa L.) cultivars to a seventh. Reciprocal comparisons were made in which leaf, pollen, whole grain, and scutellum antigens were used. The reciprocal comparisons did not estimate genotypic relationships in the same order, but produced reciprocal results, i.e., when one method estimated lower relationships the other estimated higher, often above 100%. The reciprocal results were attributed to antigens common to each cultivar and these antigens masked and confounded the qualitative differences needed to estimate genotypic relationships. The different responses of common and qualitative antigens in the reciprocal comparisons made possible an analysis method that removed much of the masking effect of common antigen differences. In these tests, whole grain and embryo mean serological relationships agree well with best genetic estimates of genotypic relationships.1 Journal Paper No J-6291 from the Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa, Project 1176. In cooperation with the Crops Research Division, Agriculture Research Service, U.S. Department of Agriculture.