Laboratory of Cellular and Molecular Cytogenetics, Department of Botany, University of Delhi, 110007, Delhi, India.
Plant Cell Rep. 1992 Dec;12(1):12-7. doi: 10.1007/BF00232414.
Comparisons of the chromosome numbers, 2C nuclear DNA amounts and karyomorphology were made in explant cultures of diploid (2n = 2x = 14) and autotetraploid (2n = 4x = 28) Phlox drummondii. In 6-36 week old calli derived from diploid internodal segment explants, and in cells of root tips regenerated from such callus, marked differences were observed in chromosome number. The chromosome numbers ranged from 2n = 14 to 2n = 100 and DNA amounts from 8.20 to 63.20 pg in the diploid derived callus, while the extent of variation was much reduced in the regenerated roots. In contrast, the autotetraploid cultures were characterised by the maintenance of the same chromosome number and DNA amounts as the mother plant. Modified chromosome structures were not apparent in any of the cultures. The possible reasons for the chromosomal instability at the diploid level and stability at the tetraploid level are discussed.
对二倍体（2n = 2x = 14）和同源四倍体（2n = 4x = 28）福禄考外植体培养物的染色体数目、2C 核 DNA 含量和核型形态进行了比较。在来源于二倍体节间段外植体的 6-36 周龄愈伤组织，以及从这种愈伤组织再生的根尖细胞中，观察到染色体数目的明显差异。在来源于二倍体的愈伤组织中，染色体数目范围从 2n = 14 到 2n = 100，DNA 含量范围从 8.20 到 63.20pg，而在再生的根中，变异程度大大降低。相比之下，同源四倍体培养物的特征是与母株保持相同的染色体数目和 DNA 含量。在任何培养物中都没有明显的染色体结构改变。讨论了二倍体水平染色体不稳定性和四倍体水平稳定性的可能原因。
