Autecological studies of Trigonella subenervis.

Investigation on ecological factors affecting on growth and development of plant species Trigonella subenervis ( wild fenugreek ) was carried out in line of auteccology research plans on important plants in rangelands of Khorassan. In first step of the study, plant provenances and habitats from all over the province were investigated and identified in order to preparing distribution map. After preparing map, three outstanding provenances includig Kame of Torbat haydariee, Joghatai of Sabzevar and Moeenabad of Birjand were selected to study other cases of the study on field containing of phenology, propagation methods, vegetation cover percent, associated plants, density, soil type etc. Phenological study was done from beginning of growth season at minimum intervals of 15 days for recording how vegetation growth, regeneration and both sexual and asexual reproduction. In addition, some seeds from the specimen of each provenance were collected to indicate germination test in laboratory. Also in each provenance, dominant plant type, associated plants, total vegetation cover percent as many as the related plant, density and frequency were identified. Soil characteristics in each provenance were investigated by digging certain profiles from depth of 0-60 cm. and analyzing the obtained data in soil laboratory. Dominant climates of the provenances are cold to extra cold semi arid. The studied region with 777353 ha. Area isextended from old and new Oughaz villages in north to Moeenabad mountains in south of Khorassan province. Other measured parameters are as the following: Altitude of the provenances ranged from 1600-2700 m., Annual mean precipitation 200-400 mm., annual mean temperature 13-17 centigrade degree and annual mean evaporation 1000-3000 mm.. Trigonella subenervis is a perennial forb with several branchrd stems and 20-60 cm. height, alternate leaves with 3 leaflets, raceme inflorescence and yellow flowers. Vegetation growth of the plant is initiated in late February that completed in late April, subsequently come in reproductive stage with appearing flowers until early June then ended to producing fruits until late July. The seeds after ripening in fruit fall immediately and subsequentlythe plant come in deciduous stage from late August to late September and finally come in dormancy and hibernation period in winter season. Also, plant reproduction and propagation is made by both sexual and asexual methods from cultivating seeds and dividing plant in dormancy stage respectively. Analysis of the soil profiles data showed light texture of the provenances bed soil ( sandy loam to loamy sand ) with PH 7 – 7/5 , EC 0/6 – 2/33 m.mohs, relative poor to relative fertility from viewpoint of nutritive substances especially in sandy regions.