|
PRINT ISSN : 2319-7692
Online ISSN : 2319-7706 Issues : 12 per year Publisher : Excellent Publishers Email : editorijcmas@gmail.com / submit@ijcmas.com Editor-in-chief: Dr.M.Prakash Index Copernicus ICV 2018: 95.39 NAAS RATING 2020: 5.38 |
Mutation is sudden heritable changes in the DNA sequence that are not derived from genetic segregation or recombination. Spontaneous mutation occurs at a very low frequency 1 in 10 lacs or 10-6. In fruit crops spontaneous bud mutation are more common called as bud sports. The occurrence of a large number of natural bud sports in citrus, mango, grapes etc. made the fruit breeders interested to breed through induced mutation. Since, mutations bring about variation, they provide the ultimate basis for evolution of new forms, varieties or species. Mutations may result into deletion, inversion, translocation of chromosome and nucleotide base substitutions. Mutation can be induced artificially with the help of various physical and chemical agents which are called mutagens. Most commonly used Physical and chemical mutagens are gamma rays and EMS (Ethyl Methane Sulphonate) respectively. Dose inducing 25 to 50% lethality (LD25-LD50) among mutated plants will result in the highest mutation rates. Perennial nature, long juvenile phase, heterozygosity, sexual incompatibilities etc in fruit crops limits their improvement through conventional breeding.