Abstract

Curculin, which is extracted from fruits of Curculigo latifolia has been found to have a sweet taste with sweetness-modifying characteristics of natural sweeteners and has been shown to be a good low-calorie sweetener. In vitro growth performance of C. latifolia cultures is limited by contamination and browning. This study was aimed to minimize the effect of phenolic components, eliminate contamination and identify suitable explants for in vitroregeneration of C. latifolia. Our results showed that the use of ascorbic acid, citric acid, polyvinylpyrrolidone (PVP), bavistin and chloramphinicol (0.1%) for 9 h significantly reduced the shoot tip explants browning. This pre-treatment was followed by 70% ethanol for 90 s, 30% Clorox^® and Tween 20 for 15 min, mercuric chloride (0.1%) for 5 min, and 10%Clorox^® for 10 min for eliminating contaminants. This technique reduced contamination (62.5% aseptic) with high survival rate (100%) of shoot tip explants. In petiole explants, pre-treatment with ascorbic acid, citric acid, PVP, bavistin, chloramphinicol and streptomycin (0.1%) for 9 h followed by the same sterilization technique significantly reduced browning and contamination (83.3% aseptic), but the percentage survival of explants was only 49.2%. Beside, rejuvenation of explants from petiole was difficult when compared to shoot tip cultures. The results showed that this technique was more efficient in sterilization of shoot tip tissue than petioles.

Keywords: Curculigo latifolia, in vitro cultures, phenolic components, sterilization technique, plant preservative mixture (PPM).