ON THE SCIENTIFIC BASIS OF CREATION OF CITRUS «TREE GARDENS»

The main breeding techniques used in the 50s of the 19th century by breeder F.M. Zorin – creator of the Friendship Tree, candidate of agricultural sciences (1944), are considered. Fyodor Mikhailovich developed valuable varieties of mandarin oranges, grapefruits, lemons, plums, figs, and hazelnuts. Author of more than 40 scientific papers. He was awarded the State Prize for the creation of new varieties of fruit plants. This article shows theoretical research and practically used methods for breeding new varieties of citrus fruits. The basis of his research was vegetative hybridization (from Greek “hybris” – inbreeding) – the production of hybrids by grafting. Zorin F.M. paid a special role in the breeding work to “tree gardens”, which were of both scientific and industrial importance. Fruits from such a tree could change shape, size, color and ripening time. At the same time, he paid attention not only to the selection of the scion, but also the rootstock. As a result, such a tree had many trunks, and the crown consisted of numerous varieties and species of three genera – Citrus, Fortunella, Poncirus of the Rutaceae family. Almost the entire Pomeranian subfamily (Aurantioideae) grafts onto each other and is highly compatible. It is important to take into account varietal characteristics: timing of flowering and ripening, as well as their biology. The main advantages of citrus «tree-gardens» are the saving of garden space, the aesthetic appearance of the trees and originality, as well as the ability to obtain more varieties per unit area.