Technique for the retention of leaf senescence of six ericoid wild plant taxa using ascorbic acid

Efficacy of a growth promoter ascorbic acid (Vitamin C) on senescence deferral action was analysed using leaf discs of six wild ericoid plant taxa. Changes of some biochemical parameters like chlorophyll, protein, soluble and insoluble carbohydrates, RNA and DNA as well as activity of catalase enzyme were analysed as reliable senescence indices during detached leaf senescence of these six species under dark condition. With the progress of ageing duration from zero to 144 hours the levels of chlorophyll and proteins in leaf discs gradually declined in both control and ascorbic acid treated samples. However, in the chemical / Vitamin-C treated samples the rate of decline was found to be much slower. Concomitantly the levels of insoluble carbohydrate, RNA and DNA started declining right from 48, 96 and 144 hours of observation period both in treated and untreated samples. And here also ascorbic acid arrested the rapid rate of reduction of the levels of the biochemical parameters. On the other hand, soluble carbohydrate level started increasing irrespective of the treatments during the whole observation periods. However, the magnitude of increase was found to be low in case of the leaf samples which experienced treatment with ascorbic acid. The activity of the enzyme catalase was found to decrease progressively during the four observation periods (0, 48, 96 and 144 hours) regardless of the treatments. Ascorbic acid partially averted the rapid fall of the enzyme activity during the ageing periods. Ascorbic acid, a nonconventional senescence deferred thus seems to be a potent senescence deferral phytohormone /chemical / vitamin at least in case of six ericoid wild plant taxa.