Classification of cultivars of common peach (Persica vulgaris Mill.)

Abstract

The existing classifications of peach cultivars are based on the morphological characteristics of vegetative and generative organs, and are of economic importance. The classification by N. I. Ryabov (1939) gained the greatest popularity. The entire cultural assortment of Persica vulgaris Mill. was divided by him into two varieties distinguished by the type of flower. A variety with a rose-shaped flower, P. vulgaris var. rosaeflora Rjab., is divided into 4 groups: 1. American early ripers; 2. Northern Chinese peaches of the ‘Chinese Cling’ type (with cartilage-like flesh texture); 3. cultivars of the Turkestan-Transcaucasian type; 4. South Chinese ‘Honey’ type peaches (honey peaches). A variety with a bell-shaped flower, P. vulgaris var. campanuliflora Rjab., is divided into two groups: 1. Iranian, the ‘Phillips Cling’ type (with cartilage-like flesh texture); 2. Iranian, the ‘Crawford’ type (with a fibrous flesh texture). The work was carried out in the collection orchard of the Research Institute of Plant Genetic Resources of Uzbekistan.Research has shown that the groups do not have a specific geographical area and consist of cultivars from all around the world. Peach cultivars are grouped according to a set of morphological characteristics, therefore, the average values of basic biological properties within a group are very close and the differences are insignificant, which complicates the use of the classification for scientific purposes.The proposed classification of peach cultivars is based on the botanical-geographical principle (Vavilov, 1935). It is proposed to divide all common peach cultivars into groups according to their geographical origin: 1. Chinese; 2. Transcaucasian; 3. European; 4. American; and 5. Central Asian. Each of these groups has its own distribution area. The biological properties of cultivars were formed under the influence of various soil and climatic conditions. Chinese peaches are frost and winter hardy and have a long dormancy period. However, in terms of commercial and taste qualities they are inferior to modern cultivars. They can be used in breeding for creating large-fruited, frostresistant, late flowering varieties. European cultivars were forming under different conditions and they should be used differentially; they are good source material for breeding cultivars with high commercial and taste qualities of fruits. Transcaucasian varieties are superior to other groups in terms of transportability. These are cultivars for canning and high quality processed products. They are relatively resistant to fungous diseases. American cultivars are distinguished by high commercial and taste qualities of fruits. Most cultivars are highly frost-resistant, but they are poorly winterhardy. They can be used for breeding highly productive cultivars with high commercial and taste qualities of fruits, with different ripening periods. Central Asian varieties have a long dormancy period, they are frost-, drought-, and soil salinity resistant. However, they are weakly resistant to fungous diseases. They can be used in breeding according to the indicated characteristics