Similarities and differences between Amaranthus species and cultivars and estimation of outcrossing rate on the basis of electrophoretic separations of urea-soluble seed proteins

The methods of distinguishing Amaranthus species and cultivars and assessme nt of outcrossing rate in grain amaranths are proposed. The collection of 2 0 cultivars and accessions of 7 species (A. tricolor, A. mantegazzianus, A. cruentus, A. caudatus, A. hypochondriacus, A. hypochondriacus x A. hybridu m and A. paniculatus) was examined. Urea-soluble proteins both from bulked samples (20 seeds) of particular cultivars, and samples which were obtained by mixing together cultivars of each species were extracted. To estimate t he outcrossing rate, the proteins were extracted from each of 100 seeds of cultivar A10 (A. caudatus). In this case seeds were collected both from iso lated inflorescences and from flowers exposed to open-pollination. The elec trophoretical separations of proteins (SDS-PAGE) were performed. The protei n pattern of 56-64 bands was detected. The samples were classified to three groups: 1- A. caudatus and A. cruentus, 2- A. tricolor and A. mantegazzian us and 3- A. hypochondriacus, A. hypochondriacus x A. hybridus and A. panic ulatus. All species can be distinguished from each other. The protein patte rn of A. tricolor (leafy type of amaranths) is considerably different from other species. The present study suggests a closer similarity between A. ca udatus and A. cruentus than between the pairs of species A. hypochondriacus /A. caudatus and A. hypochondriacus /A. cruentus. Only small differences we re seen between cultivars, nevertheless they were sufficient for distinguis hing all the cultivars. It is possible to detect outcrossing between cultiv ars, by observing that 30% of 'A10' seeds performed other patterns of prote ins. Electrophoretic analysis of seed proteins proved to be useful for dist inguishing species and cultivars of Amaranth, for describing similarity bet ween species and for estimation its outcrossing rate.