Location: Sunflower Research
Project Number: 5442-21000-039-15
Start Date: Aug 12, 2010
End Date: Aug 11, 2014
The head rot evaluation misting facility at Carrington, ND, will be used as the primary site for field Sclerotinia head rot evaluation of wild Helianthus interspecific hybrids and early generation progenies when materials become available. Backcrossed progenies of interspecific hybrids or from amphiploids will be evaluated in replicated field plots as soon as the plants reach 2n=34 chromosomes and have sufficient seeds from either self-pollination or further backcrosses. The field evaluation will be conducted every year as more progeny families are produced. Five cross combinations between amphiploids, head rot resistant wild sunflower, or stalk rot resistant wild sunflower will be made with HA 441 or HA 410, followed by backcrossing to obtain new resistant lines. For inheritance studies, these new resistant lines will be crossed with susceptible inbred line HA 234, and disease evaluations will be conducted on F1, F2, and F3 progeny families. Due to the quantitative nature of Sclerotinia resistance and low probability of obtaining the resistant recombinant, the number of 2n=34 progeny families for field test will be continuously increased throughout the years of the project. In addition, 2n=36 plants from selfed 2n=35 plants, expected to be disomic additions, will be tested in the field to identify major resistance QTLs associated with specific chromosomes. If major resistance QTLs are found, their transfer into lines HA 410 or HA 441 will be followed and the disomics will be located to specific linkage groups of the sunflower RFLP map.