VIEW ARTICLE

Computer-Generated Hypothetical Genotypes for Reaction and Pathogenicity of Wheat Cultivars and Cultures of Puccinia graminis tritici. W. Q. Loegering, Professor of Plant Pathology, University of Missouri, Columbia 65201; Coleman H. Burton, Associate Director of the Computer Network, University of Missouri, Columbia 65201. Phytopathology 64:1380-1384. Accepted for publication 12 April 1974. DOI: 10.1094/Phyto-64-1380.

Sixty-nine cultivars of wheat chosen at random from the Plant Introduction collection, 13 monogene lines, and three background cultivars were inoculated with 19 cultures of Puccinia graminis tritici. The resulting data were subjected to computer analysis to determine genotypes for high-low (H-L) reaction and pathogenicity of cultivars and cultures by means of interal and external correlation programs and a new “boxing” program. Internal correlation indicated that most of the cultivars differed in their genotypes for low reaction, and external correlation indicated that none of the cultivars had any of 13 different. Sr genes for low reaction represented in the monogene lines. The new “boxing” program permitted print-out of postulated H-L genotypes for reaction and pathogenicity for cultivars and cultures. It is suggested that such postulated genotypes are as valid as those obtained from F₂ data and are useful in plant breeding programs as well as in setting up hypotheses to be tested by geneticists.