Riyadh Muhaidat

PhD student


My PhD research focuses on pieces of the structure function relationship puzzle in an interesting taxa of C4 dicots in which the C4 syndrome has independently evolved. Whereas three biochemical subtypes occur within the C4 species of the grass family (Poaceae), only two have been so far identified in sedges and dicots (NADP-ME and NAD-ME). However, while considerable attention has been paid toward C4 monocots, C4 dicots have received little attention. Therefore, I am interested in my PhD research to focus on interesting groups of C4 dicots that have not yet been well studied. The biochemical pathways in these taxa are not known and thus make further anatomical assessments more challenging. My research falls into three main lines:


A-    Biochemical characterization of certain groups of C4 dicots. This will be assessed through enzymatic assays, identification of the initial photosynthetic products using TLC, immunolocalization of the key C4 enzymes and gas exchange properties.

B-    Comparative quantitative anatomy of assimilating organs of several taxa of C4 dicots at the biochemical subtype level and compare them with C3 relatives.

C-    Convergence of Kranz anatomy (See more) between C4 species of Haloxylon (Chenopodiaceae) and Calligonum (Polygonaceae). The species of both genera have unusual photosynthetic apparatus. Lateral green articulated shoots function as the main carbon assimilating organs, whereas the true leaves are quite reduced in the form of scale-like.


An important part of my research was the field work I did during summer, 2002 in Jordan. I collected several species; C4 and C3, from different localities mainly desert areas such as: Dead Sea Area, Wadi Araba, Wadi Al-Yotum, Wadi Rum, Al-Azraq and Ghor Al-Safi.




Muhaidat R, Al-jassabi S, El-Oqlah AA, Jaradat AA (1998). Glume morphology and comparative culm anatomy of Aegilops L. species from Jordan. PP. 135-147. Triticeae III.Ed. Jaradat AA.




Laboratory Manual Of General Biology (2001). Department Of Biological Sciences, Yarmouk University, Irbid-Jordan