**9. Conclusions**

of their hybrids are grown at the greenhouse conditions in soil. All data collected are stored

The Cytogenetical Collection of cotton currently stored in the National University of Uzbe‐ kictan at Tashkent. It is funded by Committee for Coordination of Science and Technology

**Figure 25.** Haploid plant 171/417 in cotton *G. hirsutum* obtained in M2 after pollen irradiation. (A) haploid plant; (B) fertile branch with two bolls; (C) leaf, flower and bract in parental line L-458 (1-3) and haploid plant (4-6); (D) cup,

petal and staminate column in parental line L-458 (1-3) and haploid plant (4-7).

as a hard copy catalogue book that is being conversed to electronic format.

Development (CCSTD) under the Cabinet Ministry of Uzbekistan.

**8. Location, maintenance and funding**

282 World Cotton Germplasm Resources

In conclusion we studied new Cotton Cytogenetic Collection adapted to the Central Asian condition in contrast Cytogenetic Collection from USA using different types of seed and pollen irradiation. We propose the presence of unique cotton aberrations involved chromosomes for absent chromosomes in American collection. The results suggested a detection of "reduced" stigma as a useful phenotypic marker for cotton monosomics which makes it possible to distinguish different cytotypes without cytological analyses. The results demonstrated of new unique desynaptic cotton plants in which progeny produced monosomics with high frequen‐ cy. We observed the very occurrence of univalents misdivision probably owing to monosome stability in the unique genetic background. Our cotton monosomic lines are unique and should be a valuable cytogenetic tool not only for chromosome assignment of new marker genes and genome enrichment with new chromosome deficient plant, but also for a development of new cotton chromosome substitution lines and germplasm introgression.

Alternatively, the creation of chromosome substitution lines through crossing of each of the new monosomics with *G.barbadense* genotype (Pima 3-79) is in progress. This will serve as a foundation to apply molecular marker (e g., SSPs) for the identification of our monosomics in hybrids with chromosome substitutions for a given monosome. At the same time, our monosomic cotton lines with initial cytogenetic characteristics, which developed using single genome background, should be useful germplasm for cotton researchers to use as material for future breeding genetic, cytogenetic and molecular-genetic investigation of cotton genome.

In future we plan to identify the chromosome deficiencies by molecular markers (SSR) to map of cotton genome. Also we will continue identification monosomic lines of our cytogenetic collection using a well-defined tester-set of translocation lines of the USA Cytogenetic Collection, kindly provided by Dr. D.M. Stelly, Texas A&M University, USA, under USDA germplasm exchange program.
