Obtaining Synthetic Polyploid Sources through Hybridization of Diploid Species of Gossypium L. and Their Cytological Analysis

Abstract

The wild diploid species Gossypium anomalum is considered a promising genetic resource for improving the genetic traits of cultivated cotton varieties due to its natural adaptation to abiotic (e.g., drought, high temperatures) and biotic (e.g., insects, diseases) stress conditions. Due to the challenges in hybridizing cultivated tetraploid and wild diploid species, the genome of the F1 generation, obtained from the hybridization of wild species G. herbaceum subsp. pseudoarboreum (A1 genome) and Gossypium anomalum (B1 genome), was amplified through synthetic polyploidy to restore crossbreeding fertility. Cytogenetic analysis of F1С hybrids revealed unbalanced tetrads and abnormal dyads during sporogenesis. These anomalies, resulting from genetic differences between the species, negatively impacted the fertility of the hybrids. Additionally, disturbances in chromosome distribution during microsporogenesis were observed, leading to reduced viability of pollen grains in hybrid plants. Based on these findings, it was concluded that further breeding efforts are necessary to enhance the genetic stability and restore the fertility of these hybrids.