Genetics, Vol. 178, 1117-1122, February 2008, Copyright © 2008
doi:10.1534/genetics.107.083576

Completely Distinguishing Individual A-Genome Chromosomes and Their Karyotyping Analysis by Multiple Bacterial Artificial Chromosome–Fluorescence in Situ Hybridization

Kai Wang1, Bing Guan1, Wangzhen Guo, Baoliang Zhou, Yan Hu, Yichao Zhu and Tianzhen Zhang2

National Key Laboratory of Crop Genetics and Germplasm Enhancement, Cotton Research Institute, Nanjing Agricultural University, Nanjing 210095, China

2 Corresponding author: National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
E-mail: cotton{at}njau.edu.cn

Twenty bacterial artificial chromosome (BAC) clones that could produce bright signals and no or very low fluorescence in situ hybridization (FISH) background were identified from Gossypium arboreum cv. JLZM, and G. hirsutum accession (acc.) TM-1 and 0-613-2R. Combining with 45S and 5S rDNA, a 22-probe cocktail that could identify all 13 G. arboreum chromosomes simultaneously was developed. According to their homology with tetraploid cotton, the G. arboreum chromosomes were designated as A1–A13, and a standard karyotype analysis of G. arboreum was presented. These results demonstrated an application for multiple BAC–FISH in cotton cytogenetic studies and a technique to overcome the problem of simultaneous chromosome recognition in mitotic cotton cells.