EFFECTS OF LIGHT, CARBON DIOXIDE, AND HORMONE LEVELS ON TRANSFORMATION TO PHOTOAUTOTROPHY OF SUGARCANE SHOOTS IN MICROPROPAGATION

摘要

Sugarcane (Saccharum spp.) shoots were transferred from a heterotrophic micropropagation environment and cultured on sugar-free Murashige and Skoog (MS) salts medium in the controlled atmosphere of a growth chamber. The purpose was to achieve photoautotrophic shoot culture to be used for micropropagation. Effects on the shoots were tested for three factors: carbon dioxide concentration, light level, and the hormone concentration of the growth medium. Factorial design was applied for the experiment such that all combinations of high and low factor levels were utilized, and the medium level of each factor level constituted the middle point of the design. All shoots were observed to become yellowish in color and lose vigor in the sugarless environment, although the successful treatments regained their color and vigor. Average dry weights of shoots per vessel were recorded at the end of two weeks as a quantitative measure of transformation of shoots to photoautotrophy. Light and CO 2 levels were found to have statistically significant and positive effects. The negative effect of hormone concentration was insignificant.