Gene transfer between three groups of wheat. II. Differential transmission rates of deleterious genes in 6x and 4x wheats

Abstract

Three genes representing an indigenous (B1 gene for awn suppression), an alien [Hp gene for hairy peduncle from rye), and a lethal mutant gene (vl for virescence), were transferred from eomraon sources to a 6x {Triticum aestivum cv. S-615) and 4x wheat (T. durum va,r. reichenbachii), by repeated backcrosses using the latter as recurrent pollen parents. In every backcross generation, heterozygotes of each gene were backcrossed as well as selfpollinated, and the transmission rates of these genes to offspring weredeter-mined. The B1 gene showed normal transmission in both 6x and 4x wheats. The Hp gene was transmitted normally in 6x wheat, while its transmission rate was slightly depressed (ca. 10%) through both female and male gametes in 4x wheat. The rl gene was transmitted at slightly lower frequency (about 10%) than its normal allele in 6x wheat, while its transmission rate was greatly reduced through both female (ca. 40%) and male gametes (ca. 70%) in 4x wheat. Thus, it was concluded that polyploidy increases tolerance of plants to deleterious genes. © 1983, The Genetics Society of Japan. All rights reserved.