CHARACTERIZATION OF CORNUS (DOGWOOD) GENOTYPES USING DNA FINGERPRINTING

Several horticulturally important members of the genus Cornus were characterized at the DNA level to identify genotypes. Random genomic DNA fragments from Cornus florida L. 'Barton' were cloned into pBR322 and lambda-Gem-11 and used to search for restriction fragment length polymorphisms (RFLPs) among C. sericea L., C. kousa Hance., and four cultivars of C. florida: 'Barton', 'Cherokee Princess', 'Cloud 9', and 'Mary Ellen'. Total DNA from these genotypes was restricted with several endonucleases (of which BamHI, EcoRI, and HindIII were used to search for RFLPS), vacuum-blotted onto nylon membranes, and probed with the C. florida 'Barton' DNA clones. RFLPs were common among the Cornus species sericea, kousa and florida, suggesting considerable DNA sequence divergence at the species level. RFLPs were less common among the cultivars of C. florida. These cultivars were selected from a narrow geographical area in North America from nursery-grown trees and exhibit much less DNA sequence divergence.