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

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

Efficient Elimination of Viruses from Garlic Using a Combination of Shoot Meristem Culture, Thermotherapy, and Chemical Treatment

Garlic (Allium sativum L.) is a clonally propagated bulbous crop and can be infected by several viruses under field conditions. A virus complex reduces garlic yield and deteriorates the quality of the produce. In the present study, we aimed to eliminate Onion yellow dwarf virus (OYDV), Garlic common latent virus (GCLV), Shallot latent virus (SLV), and Allexiviruses from the infected crop using combination of meristem culture, thermotherapy, and chemotherapy. In this study, seven different treatments, namely shoot meristem culture, thermotherapy direct culture, chemotherapy direct culture, chemotherapy + meristem culture, thermotherapy + meristem culture, thermotherapy + chemotherapy direct culture, and thermotherapy + chemotherapy + meristem culture (TCMC), were used. Multiplex polymerase chain reaction (PCR) was employed to detect virus elimination, which revealed the percentage of virus-free plants was between 65 and 100%, 55 and 100%, and 13 and 100% in the case of GCLV, SLV, and OYDV, respectively. The in vitro regeneration efficiency was between 66.06 and 98.98%. However, the elimination of Allexiviruses could not be achieved. TCMC was the most effective treatment for eliminating GCLV, SLV, and OYDV from garlic, with 66.06% plant regeneration efficiency. The viral titre of the Allexivirus under all the treatments was monitored using real-time PCR, and the lowest viral load was observed in the TCMC treatment. The present study is the first to report the complete removal of GCLV, SLV, and OYDV from Indian red garlic with the application of thermotherapy coupled with chemotherapy and shoot meristem culture