Interspecific hybridization of nuts of the genus Juglans in the Voronezh region

The expanding the range of tree species suitable for various forest growing purposes should be carried out through the breeding and selection of new forms and hybrids that are not only highly resistant, but also exhibit heterotic qualities that are not characteristic of local species. Consequently, for the full cultivation of plants of the genus Juglans in the Voronezh region, it is necessary to develop selection methods, including hybridization. The main goal of the work is to study interspecific hybrids of nuts of the genus Juglans and evaluate their adaptive, somatic and reproductive properties to identify and select stable, high-yielding, adaptive forms with fruits of a given quality. The authors carried out interspecific hybridization by artificial pollination of the best forms of walnut – J. regia (L.), Manchurian walnut – J. manshurica (Max.), black walnut – J. nigra (L.) and gray walnut – J. cinerea (L.), used as pollinators, as well as the heartnut – J. cordiformis (Max.), used as a mother plant. From the resulting interspecific hybrids, an experimental object was created, on which observations were carried out for 12 years. When assessing hybrids for vigor and growth energy, true somatic heterosis was revealed in hybrids J. cordiformis × J. cinerea, which at the age of 10 years outgrow both parental species by an average of 30%. This is confirmed by statistically significant differences between the values of the compared indicators (at a probability level of 0.95) – t = 4.08 (gray walnut) and 6.78 (heartnut). The hybrid variant also has a high adaptive potential (AP = 3.12), which allows it to fully compete with native breeds. No have been identified hybrids that have fruits of acceptable quality and at the same time have high adaptive potential. Based on the results obtained, hybrid forms of J. cordiformis × J. cinerea may be included in the expanded range of tree species suitable for creating forest crops and protective afforestation in the Voronezh region.