Realization of genotypic variability in tomato ( Licopersicon esculentum Mill.) in the greenhouse conditions during periodic selection

The creation of heterotic hybrids by means of conjunction of necessary alleles as result of recombination — is one of the most promising ways of adaptive selection. The raising of frequency of recombination in tomato as self-pollinator, therefore, has large value. In the present article the authors study a model efficiency of intra- and interpopulation breeding in connection with degree of genetic variability in Licopersicon esculentum Mill. tomato lines for protected soil. The Start (24-Е ½ 12-В) and Nadezhda (24-Е ½ 21-17) indeterminant hybrids and their parents forms were used as initial material. The 24-E and 21-17 parental forms, obtained by 2-year inbreeding from the Vezha local variety and the Matra Holland variety, respectively, have high combination ability on main components of productivity. The 12-B form from collection of N.I. Vavilov All-Russian Scientific Research Institute of Plant Growing, St. Petersburg has complex resistance to cladosporium and TMV. The crossing during obtaining F 1 hybrids were made by hand. The results, obtained on F 1 hybrids of Start and Nadezhda forms, were shown that used optimal schemes for periodical breeding with minimal inbreeding and regular hybridization increase the practical frequency of combination of necessary genes, influenced on productivity and resistance to diseases, and may be used for improvement of parental forms and rising of heterosis effect in hybrids. The isolated in two cycles periodical selection the F 1 hybrids excelled the initial hybrids in productivity of 6-10 % and kept the complex resistance to TMV and cladosporium, that suggests about an efficiency of present models in tomato breeding for heterosis.