Vertical-Zonal Distribution of Nematodes of Wild Plants of Zerafshan Mountains of Uzbekistan

Abstract

The purpose of the research is to study the patterns of vertical distribution of nematodes of wild perennial plants growing on the slopes of the Zerafshan mountains.

Materials and methods. Material was collected in Spring (April–May) in 2016–2018 by the route method. Objects of the research – nematodes living on 7 species of wild perennial plants collected in four high-altitude zones. To detect nematodes, we collected and analyzed samples of plants and basal soil of whole leaf cousin (Cousinia integrifolia F.), curly sorrel (Rumex crispus L.), camel thorn (Alhagi kirghisorum Sch.), creeping mustard (Acroptilon repens L.), looser loosestrife (Phlomis salicifolia Regel), onion barley (Hordeum bulbosum Torn.) and onion bluegrass (Poa bulbosa L.). The aboveground organs and the root system of plants, basal soil of the sod and sub-sod layers from a depth of 0–10 and 10–20 cm were also analyzed. A modified funnel method was used to isolate nematodes from plants and basal soil. In total, about 1200 plant and soil samples were collected. Atlases and determinants were used to identify nematode species. Morphometric measurements were carried out according to the de Man formula.

Results and discussion. In the examined wild plants and in their root soil, more than 14,000 nematodes of 121 species were found. All detected nematodes belong to two classes (Adenophorea, Secernentea), four subclasses (Enoplia, Chromadoria, Rhabditia, Diplogastria) and eight orders. Among the latter, the order Tylenchida is dominant, represented by 59 species, accounting for 48.2% of all detected nematodes. They are followed by orders of Rhabditida (29 species – 23.6%) and Dorylaimida (16 species – 13.8%). The orders Araeolaimida, Monhysterida and Mononchida have in their composition from four to seven species, the orders Triplonchida, Diplogasterida – only one species. In plants and basal soil from the upper zone of the mountain massif, 64 were found, the middle zone – 93, the lower zone – 104, the foothill zone – 79 species of nematodes. Representatives of the order Tylenchida dominate in all examined zones.