<b>Cytogenetic and flow cytometric analysis of new allotetraploid forms derived from wild cotton species with A1 and G genomes</b>

<jats:p>Wild Australian and Afro-Asian cotton species are characterized by their natural resistance to diseases and pests, serving as valuable genetic resources for the introgression of these beneficial traits into cultivated cotton varieties. This study presents the results of research aimed at determining the ploidy level of novel allopolyploid hybrid forms derived from wild Australian (Gossypium nelsonii) and Afro-Asian (G. herbaceum) cotton species using interspecific hybridization and experimental polyploidy methods. Cytogenetic analyses demonstrated that the interspecific F1 hybrids possess a diploid chromosome set (2n=2x=26), whereas the synthetic F1C hybrids developed via experimental polyploidy exhibited a multiplied chromosome set (2n=4x=52). Furthermore, flow cytometry analysis conclusively confirmed this chromosome doubling, showing that the nuclear DNA content doubled from an average value of - 12.8 in the diploid parental forms to 25.492 in the F1C allotetraploids. The study evaluated the interspecific crossability of species belonging to different genomic groups and successfully generated genetically stable synthetic allotetraploids. This demonstrates the feasibility of utilizing wild diploid species in genetic and breeding research.</jats:p>