[Effects of intergenic interaction of the high pigmentation gene hp-2(dg) (high pigment-2 dark green) with the gene B (beta-carotene) in tomato].

It was shown that during intergenic interaction of genes hp-2(dg) and B in dihomozygote an additive factor is formed activating biogenesis of beta-carotene in tomato fruits. In the genotype B/B//hp-2(dg)/hp-2(dg) there is preserved the positive effects of the gene hp-2(dg) on the content of ascorbic acid and the negative one on the content of titrated acids. With this stabilization of the gene hp-2(dg) genetic depression is observed, which is manifested in the increased productivity of B/B//hp-2(dg)/hp-2(dg)-genotypes.

[Effects of cumulative polymery of tomato ripening genes].

Results of investigation of hetero- and homozygous interconnection of tomato keeping quality genes alc, nor, rin are presented. In double heterozygotes alc/alc+//nor/nor+, nor/nor+//rin/rin+, and alc/alc+//rin/rin+ a cumulative polymery resulting in formation of a new "ong-ripening", phenotype was observed. In the case of non-allelic interconnection in double homozygotes alc/alc//rin/rin, nor/nor//rin/rin, and alc/alc//nor/nor considerable inhibition of ripening processes takes place accompanied by suppression of carotenoid synthesis which favours formation of a new "on-ripening" phenotype with green-white colour of a fruit.

[Characteristics of non-allelic interaction of genes gf and B in tomato].

Results of investigation on non-allelic interaction of mutant genes gf and B in tomato are represented. It was revealed that gf gene inhibits beta-carotene synthesis owing to incomplete transformation of chlorophyll. In a double BBgfgf homozygote the joint discrete manifestation of effects of two genes takes place resulting in a new phenotype--dirty-orange colour of a fruit.

[Formation of varieties of cultured forms of tomato and the principles of their taxonomic classification].

The literature data are summarized confirming the invaluable role of mutation process in antropogenic evolution of cultivated tomato forms. It is shown that just the presence of mutant characters was the basis for existing botanical classification of cultured tomato. Expediency and alternative of existing taxonomic conceptions of cultured tomato are discussed.

[Pleiotrophic effects of the bl gene and its practical value for selection in tomatoes].

Being of great value for creation of one-stem forms of tomato, the gene bl manifests a number of pleiotropic effects, which complicate its practical usage. There is shown that the gene manifestation depends significantly on the influence of the environment and the genetic background. Sometimes it is possible to avoid the manifestation of undesirable gene effects by creation of the favorable genetic surroundings.

[Non-allelic interaction of mutant genes of tomato].

The results on studying of mutant genes with a non-allelic interaction in tomato are presented. It is determined that the mutant c and e genes of the leaf form interact by type of recessive epistasis with predominance of the homozygote cc over ee and the manifestation of the genotype ee can be influenced by genes-suppressors. It is defined that mutants ful, l-2, au, lg interact by type of dominant complementarity in F1 and by type of recessive complementarity in F2.