Morphological characters of sugarcane mutant (Saccharum officinarum L.) from in vitro selection for drought stress

Mutation followed by in vitro selection is a breeding technique that can produce tolerant mutants to biotic or abiotic stress. The change in the resulting mutant's character is an indication that mutation has occurred. This research aimed to study changes in morphological characters in mutants selected in vitro against drought stress. Mutations were performed on callus of sugarcane variety Bululawang using gamma ray irradiation at a 5-35 Gy dose range. In vitro selection for tolerance to drought stress was carried out using PEG 6000. The research material was 25 mutants selected for drought stress tolerance in vitro, followed by in vivo selection in a greenhouse, using Bululawang variety as a control. Observations consisted of morphological characters, including leaf, leaf-sheath, internode, stem, and bud. Parent and mutants have a 0.47 dissimilarity coefficient. Each mutant changes in a different character. Changes in morphological characteristics occur in leaf characters (auricle, color, and width), leaf-sheath (hair, waxiness, and color), internode (shape and length), stem (diameter and waxiness), and bud (wing, shape, and position). Most mutants have a narrower leaf, thinner diameter, shorter internodes than their parent, and an absence of auricle. It is necessary to study further the correlation of these characters with resistance to drought stress.