Autecology of Withania coagulans (Stocks) Dunal in Sistan and Baluchestan province

Development and implementation of effective programs to conservation، reclamation and efficient utilization of valuable plant species seem to have a special importance. To achieve this goal، ecological characteristics of important plant species، forming natural vegetation، need to be detected and recognized. Withania coagulans (Stocks) Dunal، belonging to the Solanaceae family، has received much attention in recent years due to the presence of a large number of steroidal lactones، known as withanolides. One of the most important withanolides is withaferin A، having anticancer properties. To study the autecology of W. coagulans، its habitats in Sistan and Baluchestan region were identified and habit characteristics including climate، soil physical and chemical properties، altitude، slope gradient، aspect and phenological stage were investigated in several locations. Results showed that this plant is exclusively distributed in limited areas of the province. The climate of the study area is arid based on Demarton aridity index. Average annual rainfall is 124. 8 mm with a relative humidity of 32% and average temperature of 24. 2 C°. This species is mainly (45%) distributed at an altitude of 1200 to 1400 meters above sea level، in slopes، valleys، road edges and mainly in waterways and the bed of seasonal rivers and in all aspects particularly the South and a slope from zero to 74%. The soil texture of the study habits is predominantly sandy loam with a pH of 7. 5-7. 8، an EC of 0. 5-5. 2 ds/m and 8. 4-23. 1% lime. W. coagulans is a drought resistant species growing in arid climate conditions with an average annual rainfall of 150 mm. In general، essential measures need to be taken towards the conservation and distribution of this rare and valuable species.