中国水韭属植物的染色体数目及其分类学意义

利用细胞学方法观察统计了中国4种水韭属Isoestes植物的染色体数目。结果发现4个种的染色体基数均为x=11，其中高寒水韭I．hypsophila Hand.-Mazz．为2n=22，为首次报道；台湾水韭 I．taiwanensis DeVol为2n=22；中华水韭I．sinensis Palmer 2n=44为四倍体；而产于云南贵州一带并一直被当作是宽叶水韭I．japonica A．Br．的水韭属植物2n=22，与文献报道的宽叶水韭(2n=66，67，77，87，88，89)完全不同，应重新予以认识和评价。依据本文和其他相关的研究结果，对东亚水韭属植物进行了分类处理。

Chromosome numbers of the Chinese Isoetes and their taxonomical significance

Chromosome numbers of four species of Isoetes from China are reported. The basic chromosome number in the four species is x=11. A chromosome number of 2n=22 was reported for the first time in I. hypsophila Hand.-Mazz. The 2n=22 was also found for I. taiwanensis DeVol, being consistent with previous report. I. sinensis Palmer from China has a chromosome number of 2n=44, which is different from that reported for I. sinensis Palmer from Japan (2n=44, 65, 66, 68). Another species of Isoetes from the Yunnan-Guizhou Plateau, which had previously been identified as I. japonica A. Br., has been shown to have a chromosome number of 2n=22, which is completely different from that reported for the latter species (2n=66, 67, 77, 87, 88, 89). More intensive studies on this new species should be made. Data from cytology and morphology of Isoetes species in China suggest that they may provide valuable clues for a better understanding of the origin and evolution of the genus Isoetes in East Asia.