ABSTRACT
Molecular manipulation of specific genes is a very popular area of research in biotechnology. Several technological developments promise to facilitate greatly in the identification and isolation of genes. Some techniques may permit the isolation of genes from any plant, whereas others are only applicable to one or a few plant species. Genome mapping also known as chromosome mapping establishes the road map of a genome. Chromosome mapping helps to identify the molecular environment of both coding and non-coding DNA sequences. The map of a chromosome can be of two types: genetic map and physical map. After a physical map of the genome near a target gene is constructed, the Tm2a region can be cloned by chromosome walking. Several techniques exploit the fact that certain kinds of mutations lead to relatively large alterations of chromosomal structure, which can be used to isolate the corresponding genes.
