A comparative study on variability and phylogeny of Triticum species : 1. Intraspecific variability.

Intraspecific variability of A, S and D genome diploid species and AAGG and AABB allotetraploid species of the genus Triticum was examined in a comparative study using isoenzymatic characters (peroxidases of embryo plus scutellum, and endosperm; and alkaline phosphatases) of dry mature seeds. The methodology followed was based on the definition of variables from characters and three functions related with total intraspecific, intrapopulational and interpopulational variabilities. The diploid species with the greatest intraspecific variability were speltoides and longissimum, and among the allotetraploid species, timopheevii. Concerning all variables, interpopulational variability was found to be greater than intrapopulational in urartu, monococcum, timopheevii, dicoccoides and sharonensis. Intraspecific variability differences found among species are discussed with reference to Nevo (1978) and a hypothesis concerning intraspecific variability differences between allotetraploids is suggested. The final objective of the present paper is to provide information on intraspecific variability differences among species for future use in discussing the interspecific relationships.