ASSESSMENT OF THE TYPE AND DEGREE OF RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISM (RFLP) IN DIPLOID SPECIES OF THE GENUS TRITICUM

The A genome of the Triticeae is carried by three diploid species and subspecies of the genus Triticum: T. monococcum ssp, monococcum, T. mo nococcum ssp. boeoticum, and T. urartu, the A-genome donor of bread wh eat. These species carry many genes of agronomic interest, including d isease resistances, and may also be used for the genetic mapping of th e A genome. The aim of this study was to evaluate the variability pres ent in a sample of 25 accessions representative of this group using RF LP markers. Twenty probes, consisting of genomic DNA or cDNA from whea t, were used in combination with four restriction enzymes. A high leve l of polymorphism was found, especially at the interspecific level. Se lecting the most informative enzymes appeared to be of great importanc e in order to obtain a stable structure for the diversity observed wit h only 20 probes. The results are largely consistent with taxonomy and data relating to geographical origins. The probes were also tested on 14 wheat cutivars. A good correlation coefficient was found for their informative values on wheat cultivars and diploid lines. Whether the group of species studied here would be useful for genetic mapping rema ins to be determined. Nevertheless, RFLP markers will be useful to fol low genes that can possibly be introgressed from these species into cu ltivated wheat.