Genetic Studies on Growth Habit of some Important Spring Wheat Cultivars in Japan, with Special Reference to the Identification of the Spring Genes Involved

Abstract

This work was planned to identify the spring gene or genes involved in several Japanese common wheat cultivars which are important in Japan and show the spring habit of growth. As the tester stocks, a set of isolines differing each other only in a single spring gene in the same genetic background of the cultivar Triple Dirk was used. Prior to the allelic tests, the genetic constitution of these isolines, received from PUGSLEY, were retested. The results indicated that the four spring genes, Vrn 1, Vrn 2, Vrn 3 and Vrn 4, were all inherited independently and incompletely dominant over the alleles for winter habit. Eight important spring wheat cultivars in Japan were then crossed to the T'riple Dirk tester stocks and also to one winter wheat cultivar, in order to identify the genes for spring habit of growth involved. It was made clear that wheat cultivars indigenous to Japan and also those developed from hybridization between them have a single spring gene Vrn 3 in common. On the other hand, the Vrn 1 gene was found to be the main spring gene involved in wheat cultivars developed from hybridization between Japanese wheats and foreign ones. It was assumed that the Vrle3 gene was original for Japanese wheat cultivars and those having Vrn 3 were more suitable to the growing conditions in southern Japan than the cultivars with Vrn I which were developed from hybridization between Japanese wheats and foreign ones and were usually susceptible to frost damage.