Viability and enzyme activity of ageing seeds of bamboo (Dendrocalamus strictus (Roxb.) Nees) in relation to exogenous plant growth regulators

摘要

The effect of plant growth regulators (PGRs) on enzyme activity and germinability was studied at six monthly ageing intervals in bamboo (Dendrocalamus strictus (Roxb.) Nees) seeds. Enzyme activity of a amylase and beta-amylases was assayed at 48, 72 and 96 h of germination and peroxidase activity at 96, 120 and 144 h of germination after the application of PGRs, viz. GA(3) (40 ppm), IBA (20 ppm), 1,2,4-acid (1-amino-4-sulphonate-beta-naphthol, 20 ppm) and resorcinol (1,3-dihydroxybenzene; 20 ppm). All the treatments increased the activities of alpha-and beta-amylase enzyme over the control. IBA (20 ppm) and resorcinol (20 ppm) proved to be the best treatments in increasing enzymes activity after 96 h of germination and in turn the germination percentage. After six months ageing interval, the effectiveness of these two treatments increased significantly in increasing the germinability and enzyme activity and effectiveness of the treatment was highly concentration dependent. After six months of ageing, effectiveness of all treatments except IBA (20 ppm) declined. Peroxidase activity declined drastically during six months of ageing and the PGRs used in the study were not effective on membrane system repair mechanisms as the electrolyte leakage increases drastically with ageing, suggesting that ageing in bamboo seed leads to two major changes in the metabolism, viz. (i) the hormonal imbalance causing rapid loss in germinability which can be recovered only till certain stage of ageing by exogenous PGRs and (ii) the slow deterioration of membrane integrity which is irreversible, leading to permanent loss of viability.