Histological and biochemical changes in Aegle marmelos Corr before and after acclimatization

Abstract

Maximum mortality of micropropagated plants occur during acclimatization phase because plantlets undergo rapid and extreme changes in physiological functioning, histological and biochemical changes. In order to investigate the actual reason of this limitation, test samples were collected at different stages of micropropagation of Aegle marmelos Corr. (In vitro stage, acclimation stage, and field established plants). The biochemical result showed that micropropagated plantlets produced significantly low total chlorophyll (0.042 mg/g fresh weight), reducing sugar (3.227%), NR activity (1.353 NO2/h/g fresh weight) and but higher protein (0.048 µg/g) during in vitro phase. The in vitro raised plants showed abnormal histological features like altered leaf mesophyll, absence of thick cuticle, sunken stomata, poorly developed stem and root histology. These results revealed that the photoautrophic mode of nutrition during in vitro phase increased the survival rate during acclimatization compared to photoheterotrophic mode of nutrition. This suggests that photoautotrophism phenemoneon has substantial influence on the physiology and development of in vitro regenerated Aegle marmelos Corr. plantlets.