|MA, GUOJIA - North Dakota State University|
|MARKELL, SAM - North Dakota State University|
|GULYA, THOMAS - Retired ARS Employee|
Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/3/2015
Publication Date: 1/4/2016
Citation: Ma, G.J., Seiler, G.J., Markell, S.G., Gulya, T.J., Qi, L.L. 2016. Registration of two double rust resistant germplasms, HA-R12 and HA-R13 for confection sunflower. Journal of Plant Registrations. 10:69-74.
Interpretive Summary: Two major types of sunflower (Helianthus annuus L.), oil and confection, are grown globally. Oilseed sunflower is characterized by its high oil content and ranks fifth among the most important cash crops worldwide. Confection sunflower is grown on a much smaller scale, but is a very important component of the sunflower industry. Confection sunflower has a very different genetic background, making it more sensitive to the biotic and abiotic stresses than the oilseed type. Part of the reason for this is due to the breeding focus in confection sunflower on seed size, not disease resistance. Germplasm with multiple rust resistance genes is urgently need in confection sunflower to provide a durable broad spectrum resistance to this destructive pathogen. Two confection germplasms, HA-R12 and HA-R13 were developed, each containing two different rust resistant genes with high levels of resistance to the predominant and the most virulent rust race currently identified in the United States. These germplasms will be a welcome addition to the confection sunflower breeder’s efforts to provide urgently needed rust resistance genes that can be incorporated into finished commercial confection hybrids.
Technical Abstract: The confection sunflower (Helianthus annuus L.) germplasms HA-R12 (Reg. No. ______, PI 673104) and HA-R13 (Reg. No. ______, PI 673105) were developed by the USDA-ARS, Sunflower and Plant Biology Research Unit in collaboration with the North Dakota Agricultural Experiment Station, and released in July 2014. Puccinia helianthi Schwein., known as sunflower rust, is a major yield- and quality-limiting factor for sunflower production worldwide. Due to the evolution of new rust pathotypes, it is important to combine multiple resistance genes into one sunflower genotype to overcome the newly emerging virulent races. HA-R12 and HA-R13 were developed by the pedigree breeding method and DNA marker-assisted selection. HA-R12 harbors the rust resistance (R) genes, R2 from MC29 (AUS) and R13a from HA-R6, while HA-R13 contains R5 from HA-R2 and R13a from HA-R6. Marker testing and rust resistance evaluation confirmed that HA-R12 and HA-R13 each separately harbors two rust resistance genes in the homozygous condition, with both lines showing high levels of resistance to rust races 336 and 777, the predominant and the most virulent race currently identified in the United States, respectively. Germplasms HA-R12 and HA-R13 will provide urgently needed rust resistance genes that can be incorporated into finished commercial confection hybrids, providing a constant and broad spectrum rust resistance.