SUNFLOWER RUST: RACE IDENTIFICATION, HYBRID RESISTANCE EVALUATION, AND SEARCH FOR NEW SOURCES OF RESISTANCE
Location: Sunflower Research
Title: Progress on introduction of rust resistance genes into confection sunflower
Submitted to: World Wide Web
Publication Type: Other
Publication Acceptance Date: January 12, 2011
Publication Date: January 14, 2011
Citation: Gong, L., Markell, S., Vick, B.A., Hulke, B.S., Gulya, T.J., Qi, L. 2011. Progress on introduction of rust resistance genes into confection sunflower. Presentation at the National Sunflower Association Research Forum, January 12-13, 2011, Fargo, ND. Available: http://www.sunflowernsa.com/research/research-forum-presentations/2011/
Interpretive Summary: Sunflower rust (Puccinia helianthi) has emerged as a serious disease in the last few years. Confection sunflower is particularly vulnerable to the disease due to the lack of a resistance source. Keeping confection sunflower competitive domestically and internationally largely depends on the U.S. farmer's ability to produce a continued high quality crop. Crop diseases such as rust are key impediments to this continued success. In order to effectively control this disease, we are transferring rust resistance genes from oil sunflower to confectionery sunflower. To accomplish this, three oil sunflower inbred lines each harboring a different rust resistance gene were selected as resistance gene donors. Two USDA recently released confection inbred lines served as the receptor parents. After backcrossing three generations with the receptor parents and testing at each generation for the presence of the donor resistance gene, a resistant line that has approximately 94% of the genetic composition of the confection inbred lines will be available in the spring of 2011. The DNA molecular markers identified to be linked to each of the three resistance genes will facilitate the incorporation of these rust resistance genes into confectionery sunflower. Four other inbred lines, HA-R6, HA-R8, RHA397, and RHA464, were identified to resist rust race 336, the predominant race in the North America, and race 777, the most virulent race currently known. These lines were crossed with USDA sunflower line HA89 (a highly rust susceptible type) to create four populations to be used for mapping these new rust resistance genes onto a genetic map.
Sunflower rust (Puccinia helianthi) emerged as a serious disease in the last few years. Confection sunflower is particularly vulnerable to the disease due to the lack of resistance sources. The objectives of this project are to transfer rust resistance genes from oil sunflower to confectionery sunflower and to molecularly mark the rust resistance genes. After screening the resistance of a total of 104 entries to rust race 336 (the predominant race in North America) and race 777 (the most virulent race currently known), we selected three oil sunflower inbred lines, MC29 (R2 gene), HA-R3 (R4), and HA-R2 (R5) as resistance gene donors. Two USDA recently released confection inbred lines, CONFSCL B1 and CONFSCL R5, served as recurrent parents. The BC3F1 will be obtained in the spring of 2011. The identified molecular markers linked to R2, R4, and R5 genes will facilitate the rust resistance gene introgression. Four other inbred lines, HA-R6, HA-R8, RHA397, and RHA464, were identified to resist both rust races 336 and 777. They were crossed with HA89 (a highly rust susceptible type) to create four F2 populations for mapping these new rust resistance genes. Eight hundred seventy previously mapped SSR markers showed approximately 50% polymorphism among each of the four lines with HA89. F2:3 families (twenty plants for each family) derived from the cross of HA89 and RHA 464 were tested for their reaction to rust race 336 in greenhouse trials to confirm the phenotype and assign the genotype of the F2 plants.