Character of Inheritance of the Number of Fertile Nodes in Determinate Forms of Garden Pea

Abstract

The character of inheritance of the determinate stem growth type in a garden pea form having four productive nodes (cv. Pervenets with a dwarf stem) has been first studied. The analysis of first-generation hybrids obtained from crosses between indeterminate forms and determinate samples (DTR-2 and DTR-4) showed that the phenotype of all plants was characterized by a usual stem growth type and formation of buds in the stipule axiles. In the case of DTR crosses between themselves, all plants corresponded to the DTR-2 phenotype. In the case of the cross combination (indeterminate form × DTR-2), segregation at a 3 : 1 ratio was observed in the second generation. In the case of the (indeterminate form × DTR-4) variant, phenotypes of resulting plants were segregated into four classes indicating the presence of two genes. For the (DTR-2 × DTR-4) cross, a 3 : 1 segregation was observed in relation to the early bud production. The inheritance of the “number of productive nodes” trait in the cv. Pervenets is determined by two genes, one of which is not related to the determination. This fact was confirmed by the test crossing with the further evaluation of the deviation of the actual segregation from the expected one using the χ2 (chi-square) method. According to the obtained data, the crossing [DTR-2 × (Voronezhsky zeleniy × Ranniy 28-11-early budding)] resulted in a new variety characterized by a limited stem growth type and four fertile nodes that is suitable for mechanical harvesting.