Ecological Grouping Of Phytonematodes Of Pomegranate Agrocenoses Of The Surkhandarya Region Of Uzbekistan

The article provides data on the ecological grouping of detected phytonematodes on pomegranate agrocenoses of the Surkhandarya region of Uzbekistan. The study revealed 98 species of phytonematodes belonging to 5 ecological groups: pararisobionts-20 species, devisaprobionts-23, eusaprobionts-4, phytohelminths of nonspecific pathogenic effect-34 and phytohelminths of specific pathogenic effect-17.


INTRODUCTION
Phytonematodes are a heterotrophic component of biogeocenosis. They are one of the most numerous and varied groups among invertebrates. They are microscopic worms that, with the help of digestive enzymes introduced into plant tissues, digest some of them, thereby causing serious damage to the entire body of the flower and increasing the risk of infection with viruses.
In the world, much attention is paid to the identification of parasitic plant nematodes that affect the yield of subtropical crops, their species composition, distribution, ecology, seasonal dynamics on the influence of environmental factors, as well as the development of integrated measures to combat them. In this regard, it has been determined that parasitic plant nematodes cause a decrease in the productivity of Pomegranate, like many other plants, is attacked by nematodes and these parasites cause huge damage to the harvest of these crops. Therefore, the study of the nematodofauna of pomegranate plants will determine the bioecological characteristics of parasitic species, which play an important role in solving economic and social problems.

MATERIALS AND METODS
In order to study the species composition and distribution, bioecological features of phytonematodes of pomegranate agrocenoses in the period from 2005-2019 we collected phytonematodes from the root soil and root system of plants in 28

RESULTS AND DISCUSSIONS
As a result of the carried out phytohelminthological studies in the pomegranate agrocenoses of the Surkhandarya region of Uzbekistan, we found 98 species of phytonematodes belonging to 43 genera, 28 families, 7 orders and 3 subclasses. Of these, 98 species were recorded in the root soil, and 58 species in the root system of plants.

Devisaprobionts.
The group of devisaprobionts includes 23 species that belong to the orders Plectida and Rhabditida; family Plestidae (2 species), Cephalobidae (19 species), Paragrolaimidae (2 species). They were found in the root system and rhizosphere of plants.
Species Cephalobus persegnis, Eucephalobus oxyuroides, Chiloplacus propinquus, Ch. quintastriatus, Ch. sclerovaginatus and Panagrolaimus rigidus were found in the rhizosphere and root system of pomegranate plants and were the most numerous in terms of the number of individuals. Eusaprobionts. The group of eusaprobionts, in the material we studied, turned out to have the smallest number of species -4 species (4.1% -of the total number of species). The family Rhabditidae belongs to the representatives of this group. Of the eusaprobionts, Rhabditis brevispina was found in large numbers in the root system of plants and root soil, while the species Xylorhabditis operosa and Rhabditis intermedia were found only in the rhizosphere of plants in the smallest number of individuals.
Phytohelminths of nonspecific pathogenic effect. The most numerous in terms of the number of species and individuals was the group of phytohelminths of nonspecific pathogenic effect, including 34 species belonging to the orders Aphelenchida and Tylenchida; families Aphelenchidae (3 species), Aphelenchoididae (14), Seinuridae (2), Tylenchidae (7), Psilenchidae (1), Anguinidae (6), Sphaerulariidae (1). Among families in terms of the number of individuals and species composition, Aphelenchoididae occupies the first place, which is 41.2% of the total number of species and 77.5% of the total number of individuals detected by phytonematodes.