Isolation and Characterization of Sodium Chloride-Resistant Callus Culture ofVigna radiata(L.) Wilczek var. radiata

Abstract

Callus cultures were initiated from seedling root segments of mungbean (Vigna radiata (L.) Wilczek var. radiata) cv. K 851 on modified PC-L2 basal medium. Growing cells were exposed to increasing concentrations of NaCl in the medium. A concentration of 300 mol m3 NaCl proved completely inhibitory to growth of the calli. On incubation for 25 d, cells which could tolerate this concentration of NaCl grew to form cell clones. Selected clones were characterized with regard to their growth behaviour, K + , Na+ and free proline content when grown under stress as well as on normal media and were compared with the normal sensitive callus. The selected callus was capable of growing on medium containing NaCl at the inhibitory concentration. The K+ content of the selected callus was lower in the case of the NaCl medium than for the normal medium. However, the selected clones maintained higher K+ and Na+ levels, with increased salinization compared with the wild-type cells. Salt-selected cells accumulated higher levels of free proline under NaCl stress compared to wild-type cells. Under normal conditions, however, the amounts of free proline in selected and non-selected calli were comparable.