Abstract. Drought is one of the problems that decrease sugarcane productivity. Therefore it needs to develop a new drought tolerant sugarcane variety. The objectives of this research were to evaluate the response of gamma irradiated calli and drought tolerant of putative mutants through in vitro and in vivo selection. Kidang Kencana (KK) variety was used as mother plant in this study. It has high productivity but susceptible to drought stress. Embryogenic calli were induced on MS media supplemented with 9 μM 2.4-D + 4.5 μM Picloram. Six levels of Gamma rays irradiation were used (0, 10, 20, 30, 40 and 50 Gy), while two levels of Polyethylene Glycol (PEG) were used for in vitro selection (0 and 10%). The plantlets derived from in vitro selection were acclimatized and selected in greenhouse. These putative mutants were treated with drought and watering condition (control). The result showed that irradiated calli at 10 and 20 Gy were more tolerant to 10% PEG selection media compared to the negative control (0 Gy). Among 42 obtained, the 17 putative mutants had higher drought tolerance than their negative and positive controls. However, only four putative mutants had higher drought tolerance level than positive control (PSJT 941). It was concluded that gamma irradiation continued with in vitro and in vivo selection could increase drought tolerance of sugarcane.
Keywords: Saccharum officinarum L.; Induced mutation; polyethylene glycol; somaclone; selection.