In vitro mutagenesis in rose (Rosa hybrida L.) cv. Raktima for novel traits

The efficiency of gamma-ray was worked out in generating mutant populations of Rosa hybrida L. cv. Raktima. Single node cuttings (25 cuttings per treatment with 3 replications) were irradiated with different doses of gamma-rays (0, 5, 10, 15, 25, 40, 55, 65, 70 & 80 Gy) using a Co-60 source and then cultured aseptically on Murashige and Skoog basal medium supplemented with 13.31 mu M 6-benzyl aminopurine (BAP) plus 0.54 mu M alpha-napthalene acetic acid (NAA) plus 1.44 mu M giberellic acid (GA(3)) plus 0.8% w/v agar-agar to induce sprouting and shoot proliferation. The 40 Gy-treatment was found to be the LD50 dose. Morphological abnormalities, such as, fused leaves, leaf albinism and variegated leaves, were observed at the higher doses (25, 40 & 55 Gy). In vitro raised mutant plants and non-irradiated (control) plants were transferred to plastic pots 1 month after acclimatisation and examined for their morphological traits. Two types of flower colour mutants with altered or novel flower colour in comparison to original flower colour were isolated. The aim of the present study was to develop a protocol for induction of mutagenesis that could be used successfully to develop novel traits in rose.