Aminoacid composition and species relationships in genus Triticum

The genus Triticum is composed of di- tetra- and hexa-ploid species including both wild cultivated types. Based on evidence from chromosome pairing in F1 hybrids and on gross morphological and karyotype comparisons, three basic genomes -A, B and D- have been recognised in the cultivated types. Tetraploids - AABB - are thought to be originated by amphiploidy between diploids AA and BB {JENKINS, 1929; SARKAR and STEBBINS, 1956; SEARS, 1956; RILEY, et al., 1958), probably before the advent of agriculture, while exaploids - AABBDD - emerged later as a result of amphiploidy between a tetraploid AABB and diploid DD (KIHARA, 1944; McFADDEN and SEARS, 1944). The problem of confìrming the parents of polyploid types is intensifìed by the genetic heterogeneity accumulated by them in centuries of evolution. In recent times, numerous biochemical parameters, such as phenolic compounds (Dass, 1972; FROST and HoLM, 1977), proteins {JOHNSON and HALL, 1965, 1966), isoenzyme (NAKAI, 1973; MITRA and BHATIA, 1971; JAASKA, 1978) and immunochemical methods (Bozzini et al. 1973) have been used for studying the phylogenetic relationships in wheats. The present investigation on quantitative differences in the aminoacids, from hydrolyzed proteins, of different species of Triticum was undertaken in order to assess the biochemical bases of the species relationships.