Influences of exogenous sucrose on juvenile avocado during in vitro cultivation and subsequent ex vitro acclimatization

Abstract

We investigated changes in physiological characteristics of micropropagated juvenile avocado (Persea americana Mill.) cultured in three different sucrose concentrations (5, 30 and 50 g/l) for 4 weeks and subsequently acclimatized to ex vitro conditions. No significant differences in foliar concentrations of total chlorophylls, N mass , flavonoids and total soluble proteins were observed during in vitro growth or after acclimatization. However, ex vitro transfer exerted multiple effects on foliar ratios of chlorophyll a to b, total chlorophylls to carotenoids and stem N and C/N ratio. Both varying sucrose concentrations during in vitro growth and ex vitro transfer, affected the concentration of rubisco subunits independent of other photosynthetic components, viz. total chlorophylls, foliar N and total soluble proteins. These results suggest that preconditioning juvenile avocado microplants at different concentrations of sucrose modify several physiological parameters during ex vitro acclimatization, like concentrations of carotenoids and rubisco, which can improve vigour of plants in autotrophic conditions.

In vitro mass propagation of Murraya koenigii L

“…This does not necessarily reduce total plant water content since Malus plantlets acclimatized by reducing the relative humidity had a higher relative water content, which contributed to both higher survival and improved net assimilation rates (Diaz-Perez et al, 1995). Consequently, in this investigation also gradual removal of the polythene membrane for steady lowering in humidity was found effective which is in agreement with the method employed by Premkumar et al (2002) in Persea Americana. While, the previous studies (Rani et al, 2012;Khatik and Joshi, 2014) in Murraya does not report any competent plant acclimatization system by taking into consideration the different environmental parameters e.g., light and humidity.…”

In vitro propagation of avocado (Persea americana Mill. cv. Hass) through morphogenesis

“…An important biotechnological tool is the in vitro techniques that have emerged to have achieve, among other things, selection of clonal multiplication material and to scale. Various authors have already carried out trials to propagate avocado material using tissue culture (Wessels, 1996;Rodríguez, Capote & Zamora, 1999;Premkumar, Barceló-Muñoz, Pliego-Alfaro, Quesada & Mercado, 2002;Nhut, Thi, Khiet & Luan, 2008;Zulfiqar, Akhtar, Ahmad & Ahmed, 2009); notwithstanding, several limitations affect multiplication rate and rooting of in vitro material, and this in turn influences plant hardening. To solve these limitations several growth regulators and other additives have been evaluated in different studies.…”