A Study to Detect CAM Plants in Mongolia

Abstract

In order to discover CAM plants from the Mongolian flora, four species, Orostachys spinosa (L.) C. A. Mey ., O. malacophylla (Pall.) Fisch ., O. thyrsiflora Fisch . and Sedum aizoon L. of Crassulaceae D.C . family were examined in terms of their leaf anatomy , photosynthesis and transpiration intensity for a 24- hour cycle. Photosynthesis by these plants has been studied using isotope-discriminate analysis ( δ 13 C) and a special method for CAM. Transpiration was measured by the weight-method and leaf anatomy and stomatal movement by microscopy . 13 C/ 12 C value of Orostachys spinosa , O. thyrsiflora C 4 -like (-13.44 %ο ,- 18.10 %ο ), O. malacophylla , Sedum aizoon C 3 -like (-25.03 %ο ,-26.32 %ο ). CAM plant characters are clearly discovered in two species Orostachys spinosa and O. malacophylla. Although dif ferences in the acidity value cycle of Sedum aizoon in terms of a 24-hour cycle was similar to the previous two plants, stomatal movement was commonly closed during night and day showing that we need to conduct more future studies for this species. Orostachys thyrsiflora does not have CAM photosynthetic response.

Keywords

• leaf anatomy
• CAM
• photosynthesis
• transpiration intensity