Effect of Saline Irrigation Water on Seed Germination and Water uptake of Three Dry Land Tree Species, (Salvadora persica, Grewia tenax and Caparis decidua)

Abstract

The objective of this study was to study the effects of saline water on seeds germination and water uptake for three dry land species (Salvadora persica, Grewia tenax and Capparis deciduas). An experiment was carried out in Genetic Engineering laborotary in National Center for Research – Ministry of Higher Education and Scientific Research -Khartoum. The seeds were collected from North Kordofan, Red Sea State and Khartoum State for Grewia tenax, Salvadora persica and Capparis deciduas respectively. Seeds were cleaned with water and immersing them in water for 24 hours to extract seed coat and to break the seed dormancy. The seeds were then germinated in sterilized Petri dishes Whatman filter- Seed germinability was assessed by the final cumulative percentage of germination at the end of the test. The experiment was laid out in complete randomized design with four replicates for each salinity concentration for each species with 25 seeds for each replicate. Four salinity concentrations (0%, 2%, 5%, and 10%) were used to irrigate the seeds, 0% was used as control. 25 seeds were weighted by sensitive balance with three decimal for every replicate for the three species and four replicates were used for each. The dry weight was recorded for each replicate. Then every replicate was immersed into different salinity levels (0%, 2%, 5%, and 10%) separately into labeled glass beaker for 48 hours, then every replicate was weighted and the fresh weights were recorded, then the water uptake was calculated for each replicate for each concentration for each species. Data were subjected to analysis of variance (ANOVA) for confirming the differences between the species and salinity level and Duncan Multiple Range Test to separate the means. The species showed a highly significant difference (.0001) but, the concentration did not show significant difference in water uptake percentage. Salvadora persica seeds achieved high water uptake followed by Capparis deciduas and lower water up take achieved by Grewia tenax. Species and salinity concentration showed high significant variation (0.003) in seed germination. Grewia tenax scored high germination% than the other species and followed by salvadora persica and lower one scored by capparis deciduas. Grewia tenax germinated more seeds under saline water than the other species. Plant tolerance to salt stress varies with the development stage. Seed germination seem to be a major factor limiting the establishment of plants under saline conditions. NaCl generate osmotic effects and ionic stress. The species selection criteria of the three species for a particular site should be made according to the relative importance of plantation in dry lands.