Effect of physical and chemical mutagens on leaf sclerophylly and stomatal characteristics of Kinnow mandarin mutants

Abstract

In the present study, Kinnow buds were treated with different doses of gamma irradiation (5, 10, 15, 20 Gy) and ethyl methane sulphonate (EMS) (0.05, 0.1, 0.2, 0.5%). The mutated buds were chip budded in situ on Jattik khatti rootstock. Two years after the establishment of plants, the developed mutants were examined in terms of alterations in leave sclerophylly and stomatal characteristics. Irradiation doses at 10 and 15 Gy resulted in more succulent leaves as compared to EMS treated plants. The maximum reduction in density of foliar tissue (DFT) was observed at 10 and 15 Gy (12.81%) and 0.2% EMS (7.27%). Stomata length and number was significantly reduced in plants at higher doses of irradiation i.e., 15 and 20 Gy and 0.2% EMS treatment. A general diminution of 11% in stomata nmber was observed under the EMS treatment while at 20 and 15 Gy stomata number was reduced by 40.16 and 32.73% respectively. Varaition in leaf sclerophylly and stomatal characteristics of the mutants indicate that both lower and higher doses of mutagenic treatments may give rise to the mutants of economic imporatance indicating their potential use as mutagens in future breeding programmes.