国产13种鸢尾属植物的核型研究

对中国产13种鸢尾属Iris植物进行了核型研究。其中中甸鸢尾I.subdichotoma、长葶鸢尾I.delavayi、大锐果鸢尾I.cuniculiformis为中国特有。大锐果鸢尾的染色体数目及核型为首次报道,核型公式为2n=22=4m 6sm 12st(2SAT)。长管鸢尾I.dolichosiphon的核型为首次报道,核型公式为2n=22=4m 12sm 6st。中甸鸢尾的染色体数目为新报道,核型公式为2n=42=20m 22sm。矮紫苞鸢尾I.ruthenicavar.nana的染色体数目为新报道,3个居群的染色体数目均为2n=42,核型公式分别为中甸居群2n=42=30m 12sm(2SAT),丽江甘海子居群2n=42=28m 14sm(2SAT),中甸尼西居群2n=42=36m 6sm(4SAT)。结合以往的细胞学研究结果,显示尼泊尔鸢尾亚属subgen.Nepalensis是一个染色体数目变化较大的类群,其中的中甸鸢尾可能是联系野鸢尾属Pardanthopsis与尼泊尔鸢尾亚属的重要类群。已报道的紫苞鸢尾I.ruthenica染色体数目为2n=84,与我们所研究的变种矮紫苞鸢尾(2n=42)呈倍性关系,通过与相邻类群的分析比较,认为紫苞鸢尾应是由二倍体类群演化而来。还对鸢尾属内染色体数目的变化和核型进化的趋势进行了探讨。

Karyotypical studies on thirteen Iris plants from China

Cytological studies were carried out for 13 taxa in the genus Iris from China, of which three species, namely I. subdichotoma, I. delavayi and I. cuniculiformis were endemic to China. The chromosome numbers in somatic cells for each taxon were as follows: I. subdichotoma, 2n=42; I. japonica, 2n=34; I. wattii, 2n=30; I. laevigata, 2n=32; I. ruthenica var. nana, 2n=42; I. collettii, 2n=28; I. dolichosiphon and I. cuniculiformis, 2n=22; I. bulleyana, I. delavayi, I. chrysographes, I. forrestii, and I. lactea var. chinensis, 2n=40. The chromosome number and karyotype of I. cuniculiformis were reported here for the first time and its karyotype formula was 2n=22=4m 6sm 12st(2SAT). The karyotype of I. dolichosiphon was also firstly reported, whose karyotype formula was 2n=22=4m 12sm 6st. The chromosome number and karyotype of I. subdichotoma was newly observed, whose karyotype formula was 2n=42=20m 22sm. Three populations of I. ruthenica var. nana from different localities were investigated and all the three populations had the same chromosome numbers different than previously reported. The karyotype formulae for I. ruthenica var. nana were shown as follows: Zhongdian population, 2n=42=30m 12sm (2SAT); Lijiang population, 2n=42=28m 14sm(2SAT); Nixi population, 2n=42=36m 6sm (4SAT). In addition, the 2n chromosome numbers of three subgenera Limniris, Iris and Nepalensis in the genus Iris from present results and previous reports were summarized. The results showed that the chromosome number varied considerably in subgen. Nepalensis, in which I. subdichotoma was possibly a key species between the genus Pardanthopsis and subgen. Nepalensis. Chromosome number of I. ruthenica was reported as 2n=84 which was twice as much as its variety I. ruthenica var. nana (2n=42) we observed. By comparing with related groups, I. ruthenica is likely to derive from diploid group. Finally, variation of chromosome number and evolutional tendency of karyotype in the genus Iris were also discussed.