Features of Chromosome Introgression from L. into L. during the Development of Alien Substitution Lines.

The creation of L./ L. chromosome-substitution lines is an important method to transfer agronomically valuable traits from into . In this study, 30 monosomic lines of from the Cytogenetic Collection of Uzbekistan, created in the genotypic background of line L-458, were used in crosses with the line Pima 3-79 to create substitution lines. In the course of this work, new monosomic lines were identified for chromosome and monotelodisome of the Asubgenome and for chromosomes , and of the Dsubgenome using chromosome-specific SSR markers and a well-defined tester set of cotton translocation lines (USA). Compared to those in the F hybrids, a strong decrease in the crossing and setting rates was found in the BCF backcross lines, with the substitution of chromosomes , , , , and of the Asubgenome and , , , and of the Dsubgenome. The F and BCF offspring from interspecific crosses differed in their transmission of univalents. Despite the regular pairing of chromosomes and the high meiotic index, interspecific aneuploid hybrids were characterized by a decrease in pollen fertility, which may indicate hidden structural variability in these genomes that did not affect meiotic division. The identification of chromosomes using chromosome-specific SSR markers in the early stages of plant development has greatly accelerated the detection of monosomic plants. The analysis of morphobiological traits revealed that monosomic F hybrids were more similar to the donor line, while BCF hybrids were more similar to the recurrent parent but also showed previously undetected traits.