The identification of the cotton monosomics lines of Uzbek cytogenetic collection using a tester-set of translocation lines

Working group session: 
Germplasm and Genetic Stocks
Presentation type: 
poster
Authors: 
Sanamyan, Marina; Ernazarova, Dilarbo; Saha, Sukumar ; Stelly, David; Abdurakhmonov, Ibrokhim
Presenter: 
Sanamyan, Marina
Correspondent: 
Sanamyan, Marina; Abdurakhmonov, Ibrokhim
Abstract: 
In this study, we analyzed the chromosomal deficiency of 14 monosomic lines in the Uzbek Cotton Cytogenetic collection. Hybrids were created between the monosomic individuals of the Uzbek Collection and chromosomally identified homozygous reciprocal translocation lines of the Cotton Cytogenetic Collection at Texas A&M University. The monosomes were identified by analyzing meiotic metaphase I configurations of the synthesized monosomic translocation heterozygous F1 hybrids. When the monosome of such a hybrid involves neither of the translocated chromosomes, each metaphase-I cell typically includes a quadrivalent and a monosome (23 II + IV + I); when the monosome involves one of the translocated chromosomes, a trivalent typically occurs (24 II + III). For example, we observed had 24 bivalents + 1 trivalent in metaphase-I cells of the 2n-1 F1 hybrids resulting from crosses of Mo4 with the translocation line TT 13R-19R, which shows that Mo4 is either the chromosome 13 or 19. Similarly, 2n-1 F1 hybrids from cross Mo62 with translocation line TT 14R-24R formed 24 bivalents + 1 trivalent, which shows that Mo62 is either chromosome 14 or 24; we observed that Mo62 has a “reduced” stigma, which can serve as a new phenotypic marker. Two other monosomics, Mo73 and Mo90, have been associated with the tester lines TT 9R-17Ra and TT 5R-23R, respectively. However, tests of several other monosomics in the Uzbek Collection, such as Mo69, Mo71, Mo58, Mo72, Mo84, Mo85, have not shown any common chromosome pairing with tester translocation lines of known chromosomes, suggesting that additional tests are needed to identify these monosomics. The details of the translocation tests conducted will be presented.