Determination of Lethal Dose For Gamma  Rays and Ethyl Methane Sulphonate  Induced Mutagenesis In Cassava (Manihot  Esculenta Crantz.)

Kangarasu S; Ganeshram S; A. John Joel

Volume : III, Issue : I, January - 2014

Determination of Lethal Dose For Gamma Rays and Ethyl Methane Sulphonate Induced Mutagenesis In Cassava (Manihot Esculenta Crantz.)

Kangarasu S, Ganeshram S, A. John Joel

Abstract :

Chemical and physical mutagenesis has been used to raise the genetic variation in crop plants. Chemical mutagens such as EMS, MMS and sodium azide and physical mutagens such as Gamma rays, X-rays and fast neutrons have been oadly used to cause a majority of practical variations in several crops. In this research, an attempt was made to find out the effects of gamma ray and EMS on survival, shoot length, leaf length and width to identify the Lethal Dosage (LD) in cassava. The stem cuttings of potential genotype of the popular cassava cultivar H226 was exposed to different doses of gamma radiations (10-100 Gy) using 60Co as the radiation source. Also the cuttings treated using EMS with concentrations (25-200 mM). Based on the probit curve from survival of treated material the LD50 dose/concentration for Gamma rays and EMS were 27.5 Gy and 122 mM respectively. The increase in concentration of EMS, a decrease in survival, shoot length, leaf length and width was observed. In addition, shoot length, leaf length and width decreased with the increase in Gamma Dose and an abnormal decrease in survival was observed. The Lethal Dose was determined by different measurements on treated material compared to untreated control. The effective dose observed based on the reduction of growth parameters after treatment that was between 20 and 30 Gy of gamma exposure and between 75 and 125 mM in the EMS mutagenesis for the cassava cultivar H226.