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تحميل الدليل التدريبي

أسئلة شائعة

Autecology of Rhazya stricta

Awarding Institute: Research Center of the College of Food & Agric. Sciences.
Principle Investigator:
Prof. Abdulaziz M. Assaeed
Co-Investigator: Dr. Ali A. Al-Derfasi (Plant physiologist).



Rhazya stricta is a native poisonous  plant that increase in abundance over large areas of deteriorated rangelands in the Riyadh area. The plant is an evergreen dwarf shrub of the Apocianaceae family. Although no reports of livestock poisoning by the plant, heavy grazing puts the R. stricta in a competitive advantage over valuable range plants. Sometimes R. stricta forms pure stand vegetation. Therefore, rangelands infested with R. stricta may become worthless. The plant has a pharmacological value and could have a potential value as source of pesticides. Despite all that, little is known about the autecology of R. stricta. This research project is expected to yield valuable information towards management of rangelands infested with R. stricta.


Research Objectives

The objective of this study is to generate information on the autecology of R. stricta through:

  1. Studying the effects of physical environmental factors (mainly temperature and soil moisture) on seed germination and seedling growth and survival.

  2. Characterizing life history of the plant (including seed production and dispersal).

  3. Observing the rooting pattern of mature individual plants occurring naturally and of seedlings grown in a controlled environment.

  4. Studying the physiological responses of to water stress.

  5. Studying plant water relations and photosynthesis of the plant in different stages of growth as well as in different seasons of the year.



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  1. Assaeed, A.M. 2006. Germination Ecology of Rhazya stricta. 1st. European Congress of Conservation Biology. 22-26 August, 2006  Eger – Hungary.

  2. Assaeed, A.M. 2007. Seed Production and Dispersal of Rhazya stricta. The International Association for Vegetation Science 50th Annual Symposium, 23-27 July, 2007, Swansea, UK.

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