Determination of proper gamma radiation dose for creating variation in Indian garlic varieties

Abstract

Garlic (Allium sativum L.) an important neutraceutical crop. It is used as traditional medicine to aid digestion, respiration, parasitic infestation and to treat leprosy and various other diseases. But biologically garlic is sterile in nature hence for creating variation; traditional breeding methods are not applicable. Further clonal propagation method leads garlic more prone for various seed and soil borne diseases including virus infection. And natural genetic variation in morphological as well as biochemical traits is limited in garlic. Considering this is in view, among various methods of creating variation, treating bulbs with radiation is simple and easy technique. Main activity of mutation breeding using gamma radiation is to determine optimum dose (LD-50). Hence in present experiment, two garlic varieties were subjected to gamma radiation treatments (0, 1, 5, 10, 25, 50, 75 and 100 gray). Aim of this experiment is to identify LD-50 dose and then generate variation in garlic like increase in bulb size, bulb shape, high neutraceutical compounds like allicin etc. In results, both treated varieties recorded 50 percent germination at dose 10 grays as LD-50. Further on basis of survival of plantlets and final matured plants count, optimum gamma radiation dose of 5 gray for Bhima Omkar and in between 5 to 10 gray for Bhima Purple is identified as LD-50 respectively. In case of Bhima Purple, there is further need to screen the population for exact dose value of LD-50. All other morphological traits in both varieties recorded decreasing trend with increase in radiation doses. However no significant alterations observed visually in any treatment. This optimized radiation dose will be helpful for subjecting other genotypes for getting mutants and generating diversity in garlic which may have high neutracutical compounds and would suitable for processing and export.