MOLECULAR MARKER ANALYSIS OF HELIANTHUS-ANNUUS L .1. RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM BETWEEN INBRED LINES OF CULTIVATED SUNFLOWER

cDNA and PstI genomic clones have been used to assess levels of restri ction fragment length polymorphism (RFLP) in Helianthus annuus and to determine the inter-relationships between a diverse set of 24 inbred l ines. Of the cDNA clones screened 45% were useful as RFLP probes, comp ared to less than 20% from the PstI library, which showed high levels of redundancy for high copy sequences. Fifty-seven low-copy DNA probes (23 PstI and 34 cDNA clones) were used to fingerprint 12 maintainer ( B) lines and 12 restorer (R) lines. The average number of RFLP variant s per probe was found to be 3.2, with a mean polymorphic index of 0.49 , indicating that high levels of nuclear DNA polymorphism are to be fo und in cultivated sunflower. Cluster and principal coordinate analysis of the fingerprinting data clearly separated the maintainer and resto rer lines, but there was a degree of association between 2 unbranched R-lines and the B-line germ plasm pool.