Genetic diversity within and between Turkish populations of the wild progenitor of wheats, tetrapioid wild emmer wheat, Triticum turgidum var. dicoccoides, was studied electrophoretically. Forty-eight enzyme loci were assayed in 157 individual plants representing four populations of T. t. dicoccoides, across a transect of 90 km in Turkish Kurdistan. The following results were indicated: (i) T. t. dicoccoides in Turkey comprises medium levels of aiiozyme diversity. Out of 48 putative loci 19 (40 per cent) were polymorphic and the level of genetic diversity was medium He =0·057. (ii) Altogether we scored 72 alleles in the 48 loci, (iii) The population genetics structure of T. t. dicoccoides in Turkey, similar to that in Israel (Nevo et al., 1982), displayed an ecological-genetic, semi-isolated, “archipelego”. Thirteen of the 24 variant alleles (or 54 per cent) were localized, (iv) The mean genetic distance between populations was D = 0·046, range 0·019-0·082. (v) About 86 per cent of the plants (101 out of 117) analyzed by discriminant analysis were correctly classified in their population spaces, (vi) Genetic diversity, He, and some representative allele frequencies were significantly explained by two variable combinations of water, temperature or geographical factors, (vii) 63 per cent of the aiiozyme variation was within and 37 per cent was between populations, (viii) Significant gametic phase disequilibria abound, displaying allele association at the two-locus level, (ix) Strong allele associations occur at the multilocus level at the megapopulation and at each of the 4 populations. On the average, the megapopulation was 71 per cent higher in the number of expected heterozygous loci, K, than that expected under random associations; the range between populations was X(2) = 29-125 per cent. These results suggest that (i) climatic selection plays an important role in genetic differentiation of wild emmer populations, and (ii) the wild gene pool comprises significant genetic resources for utilization in wheat improvement.
|Number of pages||15|
|State||Published - Aug 1988|
Bibliographical noteFunding Information:
Acknowledgements We thank D. Zohary for field assistance and E. M. Golenberg and T. Krugman for laboratory assistance. This research was supported by grants from the Wolfson Foundation; The Israel Discount Bank Chair of Evolutionary Biology; the "Ancell-Teicher Research Foundation for Genetics and Molecular Evolution", established by Florence and Theodore Baumritter of New York, and by the Humana Inc., Kentucky.
ASJC Scopus subject areas