Submitted to: Euphytica
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/15/2000
Publication Date: N/A
Citation: Interpretive Summary: Barley yellow dwarf viruses are the most economically import virus disease effecting cereal production worldwide. Despite long term and intensive efforts to identify natural resistance genes progress has been limited often due to a lack of accurate and reliable screening methods. The disease symptoms can easily be confused with numerous other biotic and abiotic conditions or the disease is symptomless in many crops until late in the growth of the plant. The information reported here is the first step in developing a screening technique that uses a molecular marker that can identify a disease resistance gene present in the DNA of plants at any growth stage. We have identifired one major and several minor genes whose presence indicate the plant would be resistant to barley yellow dwarf. A simple test to determine presence or absence of these genes in plants provides a quick and reliable alternative to conventional methods for selecting disease resistant plants. Current methods require that young plants be infected with the virus and then grown in a greenhouse or field until maturity (several months) to observe the disease reaction and effects of the disease on plant growth. The new method can be used to screen young seedlings so there is considerable savings in time, labor and materials.
Technical Abstract: Recombinant inbred lines from the oat population Kanota X Ogle were analyzed in order to detect QTL for BYD resistance. Plants were scored for BYD symptoms in three locations (Urbana-IL, Ithaca-NY, and greenhouse), and in four years (1992, 1993, 1994, and 1995). All plants were inoculated with infected aphids at the three-leaf stage, and the scores were recorded at the early flowering stage. Two chromosomal regions were found to be associated with resistance in IL, five in NY, and eight in the greenhouse. A multiple linear model was fitted for each location and genetic background in order to evaluate the best combination of markers for selection in a backcross breeding program. In IL the best model explained 17%, 14%, and 15% of the genetic variation for 1992, 1993 and 1994, respectively. The best model for NY explained 9% of the genetic variation in 1992 and 16% in 1993. The best model for the greenhouse explained 46% and 49% of the genetic variation in 1994 and 1995, respectively. These models will allow genotypic selection for BYD resistance to the extent that the markers are linked to the QTL.