Suitability of cassava starch as a gelling agent for the in vitro culture of banana plantlets

Abstract

In this study, the suitability of cassava starch for the in vitro culture of banana tissues was investigated. A combination of cassava starch and agar was used as a solidifying agent as against pure cassava starch and pure agar. Three types of media with respect to the inclusion of cassava starch were prepared as; media with 60 g cassava starch, 6 g agar and 2 g agar+40 g cassava starch. Explants were prepared by sterilizing them with 70% ethanol which was followed by 1% sodium hypochlorite tween 20. They were then cultured at 26 0 C. The conditions in the culture room were 16 h photoperiod, 3000 lux light intensity and a relative humidity of 60%. Tissues cultured on medium with a combination of cassava starch and agar had the highest fresh weight values of 25 g and this was significantly different from those cultured on the other two media. Dry weight was also better (10 g) for plantlets cultured on a combination of cassava starch and agar, compared to those on agar alone which had dry weight value of 8 g. Medium with agar alone had a water potential of MP a and that of medium with a combination of cassava and agar was -0.3 MPa. The growth of plantlets was better on medium with cassava starch and agar combination even though the differences in some of the parameters measured were not significant. This also reflected in the number of roots produced per plantlet and subsequently the percentage survival in the nursery. Cassava starch was thus found to be a suitable substitute for agar in the in vitro culture of banana