We studied the cytogenetic characteristics of the seed progeny of the walnut (Juglans regia L.) trees introduced to and grown within the territory of the Central Russian Upland. Three seedling groups with polymorphic cytogenetic characteristics were revealed: mutable (with a high level of pathological mitoses), low mutable (with a low level of cytogenetic disturbances), and intermediate groups. Cytogenetic characteristics (mitotic activity, parts of cells at various stages of mitosis, the level and spectrum of pathological mitoses, sizes of nucleoli and the spectrum of their types, the occurrence of cells with a persistent nucleolus in the stages of meta-, ana-, and telophase) in each of the selected groups were described; homeostatic mechanisms at the cellular level were discussed. The sizes of polymorphic groups were established. The small number of seedlings with a high level of cytogenetic disturbances (7.5%) and the predominance of seedlings with medium (70%) and low (22.5%) values of pathological mitoses indicated a high degree of adaptation of the introduced walnut mother trees to the environmental conditions of the Central Russian Upland. Predictors for assigning any seedling to one of the selected model groups (mutable or low mutable) were established using ROC analysis methods. The obtained data on the qualitative and quantitative polymorphism of cytogenetic characteristics can be used for the development of recommendations for improving the system of seed production and the selection of new forms of walnut in the Central Chernozem Region.

The phytin (myo-inositol-1,2,3,4,5,6-hexacystichydrophosphoric acid) content was studied in the endosperm of five species of Juglans grown in the Central Russian Upland conditions: 1) Persian walnut (Juglans regia L.); 2) Manchurian walnut (Juglans mandshurica Maxim); 3) heartnut (Juglans cordiformis Maxim); 4) grey walnut (Juglans cinerea L.); 5) black walnut (Juglans nigra L). The walnut is shown to have the highest phytin content (31.90±0.67 mg/g wet weight) and a low coefficient of variation (Cv=4.23%). Based on the research, we can conclude that walnut is well adapted to the conditions of the Central Russian Upland and is recommended for the creation of fruit plantations by seed.