Author
Percy, Richard | |
HENDON, BRALIE - Texas Tech University | |
Bechere, Efrem | |
AULD, DICK - Texas Tech University |
Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 4/15/2015 Publication Date: 5/15/2015 Citation: Percy, R.G., Hendon, B., Bechere, E., Auld, D. 2015. Quantitative genetics and utilization of mutants. Book Chapter. doi:10.2134/agronomogr57.2013.0042. Interpretive Summary: Technical Abstract: The relatively low level of genetic variability currently available in cotton makes mutagenesis attractive to overcome this problem. Mutations can occur either spontaneously or be induced. The majority of the genes we use today are spontaneous mutants that developed over a long period of time. Induced mutants are developed with the use of physical or chemical mutagens. Ionizing radiation which includes gamma rays and x-rays have been the most common physical mutagens. Ethyl methanesulfonate (EMS) is the most widely used chemical mutagen. It is easy to use, do not require any specialized equipment, and can provide a very high mutation frequency. EMS selectively alkylates guanine bases causing the DNA-polymerase to favor placing a thymine residue over a cytosine residue opposite to the 0-6-ethyl guanine during DNA replication, which results in a random point mutation. Besides developing much needed diversity in cotton, induced mutations are used in the production of genetics resources for functional genomics, i.e., the identification of genes and the elucidation of their function. Taking advantage of the genetic information, induced mutants are used in identifying and ascribing functions to genes. By combining the high variation of mutagenized populations with novel screening methods, traits that were almost impossible to identify by conventional breeding are now being developed and characterized at the molecular level. Mutation breeding is a beneficial tool for the cotton breeder and geneticist. With a clear objective, efficient mutagenic protocol, and a high throughput and efficient phenotypic screening method, mutagenesis can be of great benefit to the improvement of cotton. |