The Relation Between Phenotypic Plasticity of Senecio glaucus L. and Some Soil Factors

This study was conducted to assess the differences of some traits of Senecio glaucus L. in relation to the variation of some edaphic factors in three selected sites at the coastal part of the Arabian Gulf near Ad Dammam city in the eastern region of Saudi Arabia. It depends on recording some morphological and physiological aspects of plants in relation to some edaphic parameters of the sustained soil, depending on mechanical and chemical analyses. It was found that soil salinity stress represents the major factor affecting the morphological and physiological characteristics of the investigated species. Traits mostly affected by salinity are: length of shoot, length of root, number of leaves per plants and the number of ray florets per capitulum. It was also found that the investigated plant growing under high salt stress is characterized by low water content, low content of chlorophyll a and high content of proline. The decrease of chlorophyll a content could be related to the decrease of water content of plant leaves under salt stress; whereas, the high content of proline in the plant tissues could be explained as an osmotic adjustment mechanism for the investigated species growing under high salinity stress