光穗鹅观草的染色体组组成

为了研究小麦族鹅观草属光穗鹅观草 (2n=4x=28)的染色体组组成,本研究成功地获得了它与斯皮卡他草 (2n=2x=14, St)、长芒鹅观草(2n=4x=28, StY)和鹅观草(2n=6x=42, StYH)的属、种间杂种,对亲本和杂种F1花粉母细胞减数分裂中期I染色体配对行为进行了分析.结果表明:光穗鹅观草是严格的异源四倍体,拥有St和Y两组完全不同的染色体组;与长芒鹅观草的染色体组同源,有较近的亲缘关系;是鹅观草属有效的物种.

Genomic constitution of Roegneria glaberrima

Intergeneric and interspecific hybridization of Roegneria glaberrima (tetraploid: 2n=4x=28) with three "analyzer" species, i.e., Pseudoroegneria spicata (diploid: 2n=2x=14, St), Roegneria dolichathera (tetraploid: 2n=4x=28, StY) and Roegneria kamoji (hexaploid: 2n=6x=42, StYH), were performed successfully. Chromosome pairing at metaphase-I in meiosis of pollen mother cells was studied in the parental species and hybrids to determine the genomic constitution of R. glaberrima. It is concluded from this study that R. glaberrima i) behaves in a strict allotetraploid nature, comprised of two different genomes; ii) contains the St and Y genomes; iii) is closely related to R. dolichathera; and i) is a valid species of Roegneria, which comprises taxa with StY and StYH genomes.