Generation and application of VNTR DNA markers to fruit trees.
Lavi U., Adato A., Kaufman D., Mhameed S., Sharon D., Lahav E., Hillel J., Cregan P. B.
Author Affiliation: Volcani Center, Agricultural Research Organization, Bet Dagan, Israel.
: 265-273
Abstract : Multilocus and single locus variable number of tandem repeat (VNTR) DNA markers have been used to identify individuals and races as well as to detect genetic linkage with genes. Multilocus VNTR markers are advantageous for identification, while single locus markers are suitable for linkage analysis. DNA fingerprint information was used to identify mango [Mangifera indica] cultivars and to analyse genetic relationships among 20 mango cultivars. Individual specific patterns were obtained for each cultivar and the probability of obtaining a similar pattern for 2 different cultivars was 9.4 × 10-6. Individual specific patterns were also obtained for 9 Carica species and for tomato and avocado [Persea americana] cultivars. Evolutionary trees, based on genetic distances, were established for the mango cultivars, tomato cultivars and accessions, and several Persea species and avocado races. Analyses using VNTR multilocus probes detected a high level of heterozygosity in these loci in avocado. By applying several methodologies of linkage analysis, a specific avocado DNA fingerprint band (p8) was identified as being linked to a gene coding for avocado fruit skin colour. Simple sequence repeat (SSR) single locus DNA markers were generated to identify linkages with the traits of interest in avocado. Because of their characteristics, these SSRs are the markers of choice for geneticists. The generation scheme for SSR markers, as well as their evaluation, are presented.