الفهرس | Only 14 pages are availabe for public view |
Abstract In the polyploid species, genetic analysis for quantitative and qualitative characters is somewhat difficult and less conclusive compared to similar ~ysis in diploid species. This difficulty is caused by the presence of gene loci, governing the same trait, on homoeologous chromosomes belonging to different genomes. These homoeologus gene loci can interact additively or non additively and greatly influence the phenotypic expression of a trait. The feasibility of monosomic analysis in tetraploids, and monosomic and nullisomic analysis in hexaploids greatly facilitates genetic somy of these species. In addition, monosomics can be employed in the solution of certain practical problems. The most efficient method of associating genes with their respective chromosomes is by monosomic analysis. The number of generations studied and the procedures followed for monosomic analysis vary slightly according to the gene action involved. Mono-telo-disomics, which are hemizygous for one chromosome arm, can be employed for locating genes to chromosome arms and for estmating the map distance of the marker from the centromere. |