Effect of Indole-3-Butyric Acid on Clonal Propagation of Mulberry (Morus albaL.) Stem Cuttings: Rooting and Associated Biochemical Changes

Abstract

Fuel wood scarcity in the Himalayan region is an established fact and mulberry (Morus albaL.) tree has a great potential in fuel and energy production. This study determines the role of indole-3-butyric acid (IBA) for rapid clonal propagation of mulberry for higher biomass and large-scale production; and examines the associated biochemical changes during rooting. The non-treated (control) and treated (1000, 2000 and 3000 IBA mg L -1 ) soft stem cuttings were cultured in mist chamber. After 50 days the rooting percentage, root number and root length were found to be higher in IBA-treated cuttings than in the nontreated ones. The rooting zone of IBA-treated and untreated cuttings were sampled at day 0 (prior to the culture in mist chamber), 15, 30, and 45 for estimation of total soluble indole content, peroxidase (POX), indole acetic acid oxidase (IAA-oxidase) and total soluble sugar (TSS). The total soluble indole, POX and IAA-oxidase were enhanced due to IBA. POX increased from day zero to day 45 of culture. IAA-oxidase kept increasing for 30 days and thereafter declined markedly. IBA initially increased TSS, which later decreased with passage of time till the 30th day both in IBA-treated and control cuttings. Thereafter, TSS content exhibited statistically non-significant variation at day 30 and 45 of culture. On the whole, IBA increased rooting phenomenon and activated carbohydrate metabolism. IAAoxidase appears to trigger and initiate root primordia, whereas POX is invo