IN VITRO SCREENING OF BRASSICA SPECIES FOR HEAVY METAL TOLERANCE

Abstract

The experiment was conducted at the Genetic Engineering Laboratory of the Department of Genetics and Plant Breeding, Sylhet Agricultural University, Sylhet, Bangladesh to find the suitable Brassica species grown in Bangladesh for tolerance of cadmium (Cd), lead (Pb) and arsenic (As), so that the appropriate cultivars can be used for genetic engineering for improving traits of heavy metal tolerance and accumulation in order to cleanup polluted agricultural soils. In this study, 5 genotypes of Brassica campestris, 3 genotypes of B. juncea and 3 genotypes of B. napus were subjected to Cd, Pb and As stresses. B. napus cv. BARI sarisha-13 was used to standardize the heavy metal tolerance (50% to 60% growth reduction) and other genotypes were used to determine their capacity of heavy metal tolerance against Cd, Pb and As stresses. Among the Brassica species the highest level of tolerance showed by B. campestris cv. BARI sarisha-9 and the lowest level of tolerance showed by B. juncea cv. Rai-5 against Cd-stress. B. juncea cv. Daulat showed the highest level of tolerance and B. campestris cv. BARI sarisha-15 showed the lowest level of tolerance against Pb-stress. Incase of As tolerance, B. juncea cv. Daulat showed the highest tolerance and B. campestris cv. Safal showed the lowest tolerance than the other genotypes of Brassica species. Therefore, two genotypes, B. campestris cv. BARI sarisha-9 and B. juncea cv. Daulat can be chosen for genetic engineering for heavy metal phytoremediation efficiently.