Extinction Threads of Astragalus Adscendensel a Valuable Source of Persian Manna (Gaz- Anguibini)

Abstract

Astragalus L. (Fabaceae) is a genus which is widely distributed throughout the temperate regions of the world. Iran is one of the main centers of diversity of various species of this genus and based on the latest<br><br>information, 804 species, with endemism rate of more than 600/o is reported, comprising more than llo/o of the Iran's flora. There are many species with ecological, social and economic importance in Astragalus<br><br>genus. Astragalus adscendens is a native species to kan and is distributed in central areas. Mannas are valuable substances which are secreted directly from plants or by the activity of some insects in hot and dry environment. ,4. adscendens produce a valuable manna called Gazanguibini as well as a high quality Tragacanth. The Manna has high economical value and is only produced from ,4. adscendens in Iran.<br><br>Unfortunately, in recent decades the population of this species in its habitat and consequently the production of manna is declined due to many reasons like fire in grassland and human activities which put this plant at the risk of loss of genetic diversity and extinction. This review considers multiple aspects to address this problem. Moreover the manna production process? the appropriate extraction method, its medicinal value, the Manna inducing insect as well as biology, propagation methods and the main habitats of A. adscendens is being discussed.In general, the findings show that the reason for decline in Manna production is mainly due to loss of the inducing insect and secondly due to changing in climate condition of A. adscendens habitat.