[Change in gene action, genotype ranks, and results of selection in a Johannesen populations under the effect of environmental factors]. / Izmeneniia sily deistviia genov, rangov genotipov i posledstvii otbora v iogannsenovskikh populiatsiiakh pod vliianiem sredovykh faktorov.

Eight mapped mutants (er, tfl, fb, fca, fd, fe, fg, and fy) of arabidopsis (Arabidopsis thaliana (L.) Heynh.) were chosen as the model for investigation of plant response to vernalization and day length. Six quantitative characters were recorded: the number of days from sowing until flowering, plant weight, stem height, number of rosette leaves, number of cauline leaves, and total leaf number. The genotypes responded differently to environmental changes, which altered the effects of genes on quantitative traits, genotype ranks, and selection consequences. A certain set of environmental factors may result in selection in favor of one genotype, and another set may result in selection for another genotype, with direction and intensity of selection being the same.

[Changes in the intensity of effect and spectrum of action on quantitative traits of genes in Arabidopsis under varying conditions of cultivation]. / Izmeneniia sily vliianiia i spektra deistvuiushchikh na kolichestvennye priznaki genov u Arabidopsisa pri razlichnykh usloviiakh ego vyrashchivaniia.

Three experiments were performed in different years to study a pleiotropic effect of two marker genes A and B on quantitative traits in Arabidopsis thaliana L. (Heynh.) Experiments differed in their conditions for plant growth (light intensity and soil fertility). In experiment 1, substitution of B- by bb did not affect the duration of the sowing-flowering period, whereas substitution of A- by aa caused a 2-day delay in flowering. Experiment 2 showed that both genes affected this trait. The delay in flowering was one, two, or three days when B- was substituted by bb, A- by aa, or A-B- by aabb, respectively. Therefore, these genes were additive. Data of experiments 3 were opposite to those of experiment 1: substitution of A- by aa did not affect the trait studied, whereas substitution of B- by bb caused a 2-day elongation of the sowing-flowering period. Thus, variations in growth conditions transformed the effects of the marker genes duration of the sowing-flowering period and changed a set of genes that determined this trait. Note that effects of A and B genes on other qualitative and quantitative traits (for example, plant height) were constant in all experiments. Therefore, transformation of a gene set, which influenced the sowing-flowering period, was not related to the repression or derepression of A and B genes.

[Experimental verification of several assumptions and methods of statistical genetics. II]. / Eksperimental 'naia proverka nekotorykh predpolozhenii i metodov statisticheskoi genetiki. Soobshchenie II.

The applicability of A. S. Serebrovsky's formulas and N. A. Sobolev's methods was investigated for a dihybrid cross. It was shown that Serebrovsky's formulas do not always lead to a correct estimation of the minimal number of genes by which the parents are distinguished. In the case of gene interaction this estimation sometimes proved to be exaggerated 2-4 times. A test of Sobolev's method demonstrated that this method cannot be considered as reliable for work. Most of his estimations are not correct. Various estimations of the same phenomenon are often contradictory.