[Monomorphism of isoenzyme loci in natural and cultivated amaranth (Amaranthus L.) populations].

Starch gel electrophoresis was used for isozyme analysis of ADH, GDH, MDH, IDH, and ME in populations of amaranth. Experiments were performed with 93 populations and 4 cultivars. Some populations proved to be polymorphic, and this fact allowed analysis of the genetic control of the enzymes listed. The populations examined showed poor allozyme variability. Monomorphism for all loci studied was observed in 73 populations and 4 varieties. Starch gel electrophoresis was used for isozyme analysis ofADH, GDH, MDH, IDH, and ME in populations of amaranth. Experiments were performed with 93 populations and 4 cultivars. Some populations proved to be polymorphic, and this fact allowed analysis of the genetic control of the enzymes listed. The populations examined showed poor allozyme variability. Monomorphism for all loci studied was observed in 73 populations and 4 varieties. Only some populations demonstrated rare polymorphism for a single locus each: Adh, Mdh 2, Gdh, Idh 1, Idh 2, or Mod 2. The results demonstrate genetic monomorphism of amaranth for the studied loci.

[Isozyme analysis in a genetic collection of amaranths (Amaranthus L)].

In various populations of the cultivated and weedy amaranth species, the electrophoretic patterns of alcohol dehydrogenase (ADH), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH) and malic enzyme (Me) were studied. In total, 52 populations and two varieties (Cherginskii and Valentina) have been examined. Allozyme variation of this material was low. Irrespective of species affiliation, 26 populations and two varieties were monomorphic for five enzymes; a slight polymorphism of three, two, and one enzymes was revealed in three, nine, and fourteen populations, respectively. A single amaranth locus, Adh, with two alleles, Adh F and Adh S, controls amaranth ADH. Two alleles, common Gdh S and rare Gdh F, control GDH; no heterozygotes at this locus were found. The MDH pattern has two, the fast- and slow-migrating, zones of activity (I and II, respectively). Under the given electrophoresis conditions, the fast zone is diffuse, whereas slow zone is controlled by two nonallelic genes, monomorphic Mdh 1 and polymorphic Mdh 2 that includes three alleles: Mdh 2-F, Mdh 2-N, and Mdh 2-S. Low polymorphism of IDH and Me was also found, though their genetic control remains unknown.

[Intrapopulation variability of some meadow plant species with respect to their ability to accumulate 90Sr]. / Vnutripopuliatsionnaia izmenchivost' nekotorykh vidov lugovykh rastenii po ikh sposobnosti kontsentrirovat' 90Sr.

Field and laboratory studies of different plant species revealed the presence of intraspecific polymorphism in respect of the ability to accumulate 90Sr. The populations consisted of the plants effectively and ineffectively accumulating 90Sr; the former were capable of two to thirty-seven times higher accumulation than the latter. The proportion of the plants with high accumulating ability can reach 10%. Judging by the high values of the coefficients of correlation between the laboratory and field data, the results of the 90Sr content analysis different plant species were highly concordant. Accumulation of 90Sr by plants is in direct relation to its content in soil, but within the limits of the same contamination density, and is controlled by the plant genotype.

[Seed set analysis in three amaranth species (A. cruentus, A. caudatus, and A. lividus) under self- and cross-pollination conditions]. / Analiz zaviazyvaemosti semiian u trekh vidov amaranta (Amaranthus cruentus L., A. caudatus L.,i A. lividus L.) pri svobodnom opylenii i samoopylenii.

Seed set was analyzed in three amaranth species (A. cruentus, A. caudatus, and A. lividus) under conditions of self- and cross-pollination during four vegetative periods in 1995-1998. It was demonstrated, that the populations of these species are polymorphic for the breeding system and that they consist of self-sterile and self-fertile plants. The populations were composed mostly of self-sterile plants and the percentages of self-fertile plants were only 34.7%, 18.7%, and 12.5% for A. cruentus, A. caudatus, and A. lividus respectively. The level of self-fertility was high in the first year of isolation, it sharply decreased during the subsequent years of selfing, due to inbreeding effect. Seed set under self- and cross-pollination is determined by species-specificity of the plants, influence of conditions of their growth, and inbreeding depression. Conditions of growth had the strongest influence on seed set. Index of its influence varied from 0.53 to 0.87 for the cross-pollinated plants and from 0.13 to 0.68 for the self-pollinated ones. Analysis of variance demonstrated a weak effect of the interaction of these factors. Spearman's rank correlation demonstrated a highly significant agreement between the seed set values for the self- and cross-pollinated plants of A. cruentus and A. lividus. The lines derived from the three amaranth species varied widely in the seed set values under both self- and cross-pollination conditions.