|Gulya Jr, Thomas|
Submitted to: Proceedings Sunflower Research Workshop
Publication Type: Proceedings
Publication Acceptance Date: 3/10/2006
Publication Date: 3/10/2006
Citation: Feng, J., Seiler, G.J., Gulya Jr, T.J., Jan, C.C. 2006. Development of Sclerotinia stem rot resistant germplasm utilizing hexaploid Helianthus species. 28th Sunflower Research Workshop, January 11-12, 2006, Fargo, ND. Available: http://www.sunflowernsa.com/research/research-workshop/documents/Feng_Sclerotinia_06.pdf Interpretive Summary: Sclerotinia sclerotiorum (Lib.) is considered one of the most destructive pathogen for sunflower, which causes white rot and wilt. No complete resistance has been identified in the cultivated sunflower. However, some wild Helianthus species, e.g. Helianthus californicus DC. and H. schweinitzii T and G, are supposed to be potential sources of disease resistance and can be exploited in interspecific crosses to increase the genetic variability of cultivated sunflower. Among USDA released tolerance lines, HA 410 had the lowest percentage of Sclerotinia-infected plants among the eight released Sclerotinia-tolerant lines for stem rot. Therefore, the main objectives of this project were to transfer new resistance genes from these two perennial species into HA 410 and to develop new germplasm lines superior to HA 410. The interspecific hybrids between HA 410 and H. californicus and H. schweinitzii were produced via an embryo rescue technique. Greenhouse evaluation indicated excellent stem rot resistance for interspecific F1 progeny and HA 410. Most F1 progenies had good backcross seed set, but with much lower sib-pollinated seed set.
Technical Abstract: All interspecific hybrids between HA 410 and H. californicus and H. schweinitzii were produced using an embryo rescue technique, and the seedling survival rate was high. Our greenhouse evaluation indicated excellent stem rot resistance for interspecific F1 progeny between H. californicus and H. schweinitzii, and HA 410. Most F1 plants with resistant to stem rot produced acceptable backcross seed set for further evaluation. BC1F1 progenies are presently being established in the greenhouse, and will be subjected to artificial inoculation, and the resistant selections will be backcrossed with HA 410.