|Gulya Jr, Thomas|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/29/2004
Publication Date: 9/1/2004
Citation: Jan, C.C., Quresh, Z., Gulya Jr, T.J. 2004. Registration of seven rust resistance sunflower germplasms. Crop Science. 44:1887-1888. Interpretive Summary: Wild sunflower species are valuable genetic sources for the improvement of cultivated sunflower. Sunflower rust is one of the most important diseases affecting sunflower production. Seven sunflower germplasms, each with resistance to the four prevailing North American (NA) races of rust, were derived from hybridization between susceptible inbred line HA 89 and with resistant plants of seven highly resistant wild Helianthus accessions. These germplasms will provide diversity for genetic resistance to the prevailing sunflower rust races and are available for use in sunflower breeding and genetic programs.
Technical Abstract: Seven sunflower (Helianthus annuus L.) germplasms, PH1 to PH7, with resistance to the four prevailing North American (NA) races of rust (races 1, 2, 3, and 4) [caused by Puccinia helianthi Schw.], were cooperatively developed and released by the USDA-ARS and the North Dakota Agricultural Experiment Station. The germplasms were derived from hybridization and backcrossing of the susceptible inbred line HA 89 with seven highly resistant wild Helianthus accessions. Resistant plants of each wild Helianthus population were crossed with HA 89 as the male parent. The F1 progeny with combined resistance to all the four NA races were backcrossed with HA 89 as the male parent. Those resistant BC1F1 plants were again backcrossed to HA 89. A single plant from each accession was selected as the donor parent for each generation to be crossed with HA 89 to produce F1, BC1F1, and BC2F1 generations. One resistant BC2F1 plant from each accession was selected and self-pollinated. A minimum of 15 resistant BC2F2 plants from each accession were self-pollinated to produce the BC2F3 generation. More than 30 random BC2F3 plants were self-pollinated to produce BC2F4 seed for distribution. Each germplasm is expected to have dominant resistance genes at an approximate frequency of 75%. These germplasms have 87.5% cultivated H. annuus and 12.5% wild Helianthus nuclear genes in HA 89 (H. annuus) cytoplasm. Most plants are single-headed and self-compatible. Seeds are either black or black with white stripes.