Indian Journal of Horticulture

In vitro mutagenesis study was conducted by taking the some commercially important rose cultivars. In vitro grown meristems of Rosa hybrida cvs. First Red, Cri Cri and Pusa Gaurav were used with various concentrations of ethyl methane sulfonate (EMS) to develop mutants. Depending on the concentration used, fifty percent survivality was obtained in microshoots pretreated with 1% EMS in 6 hours. The treated microshoots were used further for shoot multiplication. The maximum rate of shoot multiplication was obtained on MS medium supplemented with various concentrations and combinations of 2.0 mg/l BA, 0.25 mg/l NAA, 100 mg/l Ads, 0.5 mg/l GA₃ and 1% (v/v) EMS. The elongated shoots were rooted on ½ strength MS medium supplemented with 0.25 mg/l IBA within 2 weeks of culture. About 70 to 75% of rooted plantlets survived in the greenhouse. The genetic variation was detected among the in vitro raised plants by using RAPD markers. The result showed that 22.9, 19.2 and 27.1% polymorphism was obtained among the in vitro raised plants of ‘First Red’, ‘Cri Cri’ and ‘Pusa Gaurav’ respectively. The in vitro raised mutants as well as control plants were grown in the pots and flowered. There was variation between mutant and control plants morphologically with regard to height of plants, number of branches, number of flowers, stalk length of the flower, leaf size and number of petals/flower. This study will help for developing mutants for rose improvement programme.