Seed germination of north American species of the genus Carya, promising for cultivation in Moscow region

The purpose of research is to study the characteristics of seed germination of North American representatives of the genus Carya grown in the conditions of the Moscow Region. The objects of study are the fruits of three species of hazel: Carya cordiformis (3 samples), C. laciniosa and C. ovata. Morphological characteristics of fruits were described visually. To measure the fruits, a ShTs-II-250-0.05 caliper was used. The fruits prepared for sowing were cleaned from the fleshy part of the pericarp and stored in a refrigerator (t about 5 °C), without prior drying. Sowing was carried out in containers at a depth of 1-2 cm, in a mixture of neutralized peat: soddy soil: sand = 3 : 2 : 1. The crops were subjected to cold stratification: the containers were kept in an unheated greenhouse for 3 winter months, while they were subjected to natural temperature fluctuations , including short-term freezing. It has been established that representatives of the species Carya lacinosa (Berlin-Dahlem Botanical Garden, Germany) have the largest nuts, the average length of which is 3.953 ± 0.159 cm, and the diameter is 3.207 ± 0.094 cm, smaller nuts are in representatives of the species Carya cordiformis, the average length is 1.793 ± 0.064 cm, and the diameter is 1.744 ± 0.044 cm. The Carya ovata nuts (Tarandt Forest Botanical Garden, Germany) occupy an intermediate position among the presented species in terms of their indicators. The length value is 2.538 ± 0.055 cm, diameter is 2.788 ± 0.113 cm. Carya lacinosa seeds (Berlin-Dahlem Botanical Garden, Germany) have the highest germination rate - 100.0 %. The lowest germination rate is observed in Carya ovata (Tarandt Forest Botanical Garden, Germany) - 25 %. Samples of Carya cordiformis from different places of growth occupy an intermediate value: Carya cordiformis (Botanical Garden of the University of Warsaw, Poland) - 46.7 %; Carya cordiformis (Indian Heights Park, USA) - 45.5 %. The germination of the studied seeds of C. lacinosa exceeds this indicator from the literature; in C. cordiformis and C. ovata, the germination of seeds is lower than that indicated in the literature. The most promising for seed propagation in the conditions of central Russia is C. lacinosa, and the least promising is C. ovata.