Annual Report: 2005

Development of Sclerotinia Resistant Germplasm Utilizing Wild Helianthus Species

Principal Investigator:
Dr. Chao Chien Jan
USDA-ARS-RRVARC
Fargo, ND

2006 Annual Report:
This report serves to document research conducted under Cooperative Agreement 58-5442-5-291 between the ARS and North Dakota State University, Department of Plant Sciences.  Additional details of research can be found in the report for the parent project 5442-21000-027-00D, "Enhancement of Sunflower Germplasm Diversity through the Use of Wild Species and Genome Characterization."

The 18 head-rot resistant Helianthus maximiliani and H. nuttallii accessions identified by NDSU scientists, with consistent results for three years, were crossed with NMS HA 89, and over 100 F1 plants were established for further crosses with head-rot tolerant HA 441.

Evaluation in 2005 at Mapleton, ND, indicated total resistance in wild perennial species H. maximiliani, H. divaricatus, H. giganteus, H. decapetalus, and H. grossesserratus, while the susceptible checks were 100% infected.  These resistant wild accessions are expected to provide valuable genes for our pyramiding with the moderately tolerant lines HA 441 and HA 410.  Previously identified stem-rot resistant H. schweinitzii, and H. californicus were crossed with stem-rot tolerant line HA 410.  Their F1 plants were resistant to stem rot and with good backcross seed set.

Field evaluation of interspecific amphiploids indicated excellent stem rot resistance for five amphiploids, with the amphiploid involving H. nuttallii segregating for head rot resistance.

Contact Information:
Dr. Chao Chien Jan, Research Geneticist
USDA-ARS-RRVARC
Northern Crop Science Laboratory
1307 18th Street North
Fargo, ND  58105-5677
701-239-1319