Intraspecific differences of section on root head of siler (Saposhnikovia divariacata (Turcz.) Schischkin) in Mongolia

Abstract

The present study reveals intraspecifi c diff erences in root head sections of Saposhnikovia divaricata, and explains controlling factors. Root head sections have been divided into three categories, and these were compared to factors of geography, climate, fi re and human activities. The category clearly distinct section was predominantly recorded in Dornod and Selenge-Tuv-Arkhangai provinces but it showed lower frequency in Khentii and Sukhbaatar. With respect to administrative province, it was more common in Bayan-Uul, Sergelen, Dashbalbar and Tsagaan-Ovoo sites, Dornod province; in Dadal, Norovlin and Bayan-Khutag sites, Khentii province and Shaamar, Zuunduren and Altanbulag, Selenge province. The frequency of that category increased with more droughts during early summer and over lower aridity index and in pasturelands. It was higher on wild roots of S. divaricata than in cultivated ones. The frequency of category poorly recognized section was higher in Zuunkharaa, Nomgon and Siakhan sites, Selenge province while that of the category not-sectioned root head was higher on cultivated roots. The results of our study suggest that frequency of clearly distinct section on root head decreased by coldness, strong fi re frequency, trampling and/or gathering and cultivation.