Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 1, 2002
Publication Date: November 1, 2002
Citation: MORNHINWEG, D.W., PORTER, D.R., WEBSTER, J.A. INHERITANCE OF RUSSIAN WHEAT APHID RESISTANCE IN SPRING BARLEY GERMPLASM LINE, STARS-9577B. CROP SCIENCE. 2002. v. 42(6). p. 1891-1893. Interpretive Summary: A new Russian wheat aphid (RWA)-resistant barley germplasm line was released to barley breeders. In order for breeders to effectively use this line in their breeding programs they need to know the inheritance of RWA resistance in this germplasm. The inheritance of RWA resistance in this germplasm line was determined through a detailed genetic study. We found RWA resistance in this new germplasm line to be controlled by alleles at two loci. Now both public and private breeders can effectively utilize this germplasm in their breeding programs to develop RWA-resistant cultivars that can be utilized by barley growers in all states where RWA has significantly reduced yield.
Technical Abstract: The Russian wheat aphid (RWA), Diuraphis noxia (Mordvilko), has become a major pest of barley (Hordeum vulgare L.) in the western United States. STARS-9577B, a six-rowed, spring barley with a high level of resistance to RWA, was recently released (PI 591617) for utilization by barley breeders in barley improvement. This study was conducted to determine the genetic control of RWA resistance in STARS-9577B. Crosses were made between Morex, a susceptible, six-rowed, malting barley cultivar and STARS-9577B. Genetic analyses were performed on reaction of parents, F1, reciprocal F1, F2, backcross (BC1F1) populations, and 300 F2-derived F3 families to RWA. Segregation in the F2 and BC1F1 poulations indicated multiple gene control. Seventy-five F3 families were found to be homozygous resistant, 11 were homozygous intermediate, and 18 were homozygous susceptible, indicating two genes control RWA resistance. Analysis of data from the F2 and BC1F1 to both parents suggested RWA resistance in STARS-9577B is controlled by dominant alleles at two loci, with alleles at one locus expressing sa greater level of resistance than alleles at other locus.