Allelopathic assessment for the environmental biosafety of the transgenic oilseed rape lines harboring the antifungal synthetic chitinase (NiC) gene

Abstract

Brassica is famous for its contribution to fulfil the edible oil demand. Allelopathic tests were conducted on two varieties of Brassica napus i.e., Durr-e-NIFA (DN) and Abasyn-95 (AB-95) and their corresponding six transformed lines .The transgenic lines harbor synthetic chitinase gene (NiC) that confers resistance against Alterneria brassicicola. Allelopathic assessments were conducted on plant parts and the below ground soil samples of corresponding transgenic and non-transgenic lines using sandwich bioassay method. No difference was found in the effect of transgenic and non-transgenic lines (when using either fresh or dry leaf sample) on seed germination and seedling length of lettuce. Similar non-significant differences were found between the transgenic and non-transgenic lines for lettuce seeds germination in soil. The impact of root secreta from lines of both varieties was determined on fungi, actenomycetes and bacteria (microbes of the rhizosphere). Non-significant variation was found between transgenic and their corresponding non-transgenic lines for all the three tested microbes. In comparison to DN variety and the transgenic DN lines, the AB-95 variety and its transgenic lines showed slightly higher CFU (colony forming units) values. However, these differences were non-significant and considered to inherent differences between the two varieties. On overall basis, a substantial equivalence was considered on transgenic and non-transgenic lines for all the tested bioassays.