In vivo and in vitro studies on heavy metals tolerance in sesbania grandiflota L. +CD

number: 
1726
إنجليزية
Degree: 
Imprint: 
Biotechnology
Author: 
Shaimaa Abdul Wahab Yousir
Supervisor: 
Dr.Kadhim M. Ibrahim
year: 
2007
Abstract:

In an attempt to enhance heavy metal tolerance in tissue cultures and intact plant of S. grandiflora. Several experiments were carried out. Callus was induced on cotyledon explants and maintained on MS medium upplemented with (0.5) mg/l BA and (2) mg/l 2,4-D. Heavy metals (Cd, Co, Cu, Cr and Zn) were added to the culture medium at different concentrations as ontamination agents.Results showed that callus fresh weight decreased with increasing heavy metals concentrations in cultural medium.In order to asses these heavy metals on seed germination, seeds were sown in soil contaminated with different concentrations of heavy metals for 3 weeks. Result showed that germination percentage and plant height increased over time. However a reduction occurred in these parameters with increasing of heavy metals level. Atomic Absorption Spectrophotometer 5000 was used for analysis of samples taken from whole plants and callus culture Levels of metals accumulated in callus were (0.001, 0.011, 0.012 and 0.013%) at (0.0, 0.05, 0.075 and 0.1) mg/l Cd respectively, (0.001, 0.008, 0.016 and 0.006%) at (0.0, 0.1, 0.25 and 0.5) mg/l Co respectively, (0.001, 0.020, 0.034 and 0.015%) at (0.0, 0.075, 0.2 and 0.5) mg/l Cu respectively, (0.001, 0.013, 0.012 and 0.010%) at (0.0, 0.25, 0.4 and 0.5) mg/l Cr respectively and (0.027, 0.051, 0.059 and 0.056%) at (0.0 , 0.75, 1.0 and 1.5) mg/l Zn respectively. Levels of metals accumulated in whole plant were (0.08, 0.55, 1.11, 0.83 and 0.44%) at (0.0, 1.0, 2.0, 3.0 and 4.0) mg/Kg soil Cd respectively, (0.11, 0.22, 0.55, 0.47 and 0.44%) at (0.0, 15.0, 30.0 45.0 and 60.0) mg/Kg soil Co respectively, (0.01, 0.10, 0.57, 0.58 and 0.72%) at (0.0, 25.0, 50.0, 75.0 and 100.0) mg/Kg soil Cu respectively, (0.08, 0.80, 1.28, 1.31 and 0.88%) at (0.0, 25.0, 50.0, 75.0 and 100.0) mg/Kg soil Cr respectively and (0.06, 1.11, 1.20, 1.83 and 2.22%) at (0.0, 100.0, 200.0, 300.0 and 400.0) mg/Kg soil Zn respectively.