Nature of inheritance of valuable economic traits of tobacco in F1 hybrids obtained as a result of reciprocal crossings

Abstract

Goal. To study the hybrid material of tobacco of the first generation, obtained as a result of reciprocal crossings, according to the manifestation of heterosis of economically valuable traits and the nature of their inheritance. Methods. Field (phenological observations, biometric measurements), laboratory (determination of the materiality of the leaf blade). Statistical data processing (determination of indicators of hypothetical and true heterosis, as well as the degree of phenotypic dominance) was carried out using Microsoft Excel software. Results. The results of studies of the manifestation of heterosis in 12 hybrid combinations of F1 tobacco, obtained as a result of reciprocal crossings, are given. A significant difference in quantitative indicators in direct and reverse crosses indicated the unequal influence of maternal and paternal forms on the genotype of hybrids and confirmed the participation in the process of genetically active cytoplasm. Heterosis indicators of plant height were inherited from positive overdominance in 50% of hybrid combinations to a negative effect of heterosis (50%), the number of leaves was inherited in general according to the principle of partial callous dominance (75%). The characteristics of the length and width of the leaf blade were inherited independently of each other, as evidenced by different indicators of true and hypothetical heterosis in direct and backcrosses. The effect of he­terosis and the degree of phenotypic dominance according to the materiality of the leaf blade was noted in the majority of hybrid combinations (85%). Conclusions. Hybrids with the best indicators of heterosis and the degree of phenotypic dominance in terms of yield were selected for further selection work: in the hybrids Berlei 38 / Amerikan 251 and Berlei 7 / Berlei 38, the hypothetical heterosis was 13.4 and 13.0%, the true heterosis was 12.1 and 11.3%, hp — 1.2 and 8.5, respectively. The hybrids Amerikan 251 / Berlei 38 and Virginia / Vislitsa had somewhat lower indicators: hypothetical heterosis — 9.2 and 7.2%, real heterosis — 8.3 and 3.1%, hp — 0.8 and 1.8, respectively. Tobacco varieties Berlei 38, Virginia, Vislitsa, and Berlei 7 should be used as donors of valuable economic traits (number of leaves, size of the leaf blade, high materiality of the leaf) during selection for heterosis.