ABSTRACT
Deficiency refers to any chromosome loss and may be terminal or intercalary. The recessive gene expresses in both types; it is known as pseudodominant and has been effectively utilized for locating qualitative genes in the chromosomes of maize and tomato. Deficiencies in chromosomes of diploid plants are rarely identified, however, they have been induced by irradiating pollen grains of normal plants by X-rays and fast neutrons. The irradiated pollens were pollinated onto recessive homozygous morphological mutants. Chromosome pairing at pachynema stage. Appearance of recessive gene in crosses from mutant female and X-rayed pollen, known as pseudodominant technique. An extra chromosome segment is attached to either the same homologous chromosome or transposed to one of the nonhomologous members of the genome. The telocentric chromosome is identified at mitotic metaphase or at meiotic pachynema. Somatic metaphase chromosome by acetocarmine staining identified Triplo 5L in barley. Giemsa N-banding verifies the acetocarmine staining and clearly showed that telocentric chromosome contains half of the kinetochore.
