野牡丹科6种植物染色体数目及核型分析

The Chromosome Number and Karyotypes of Six Species of Melastomataceae

研究了野牡丹科国产野牡丹属（MelastomaL．）4种植物和从国外引种的蒂牡花属（TibouchmaAubL）2种植物的染色体数目，并对4种野牡丹属植物的核型进行分析。结果表明，野牡丹属植物的染色体数目为2n=24，为二倍体植物，蒂牡花属的蒂牡花（T.urvilleari）和银毛野牡丹（T．hetemmall）的染色体数目为2n=36。核型公式为：野牡丹（Mmalabahricum）2n=10m（2SAT）＋14sm；毛稔（Msmguineurn）2n=10m＋12sm＋2st；地稔（M.dodecmdrum）2n：12m＋12sm；细叶野牡丹（M.intermedium）2n=12m＋10sm＋2st。核型分析表明国产野牡丹属植物染色体为小染色体，绝对长度为0．43～1．79μm；核型不对称系数为59．47～62．91，均属2B型。野牡丹属植物的核型为首次报道。

The chromosome numbers of six species of Chinese Melastoma L. and Tibouchina Aubl. in Melastomataceae and karyotypes of four speices of Melastoma were investigated. The results showed that the four Chinese Melastoma species was found to be diploid with the chromosome number 2n = 24. The chromosome number of Tibouchina urvillean and T. heteromall was 2n = 36. The karyotype formulae were as follows： M. malabathricum 2n = 10m（2SAT） ＋ 14sm; M. sanguineur 2n = 10m ＋ 12sm ＋ 2st; M. dodecandrum 2n = 12m ＋ 12sm; M. intermedium 2n = 12m ＋ 10sm ＋ 2st. The karyotype analysis showed that the chromosomes in Melastoma were short in length, ranging from 0.43 to 1.79 μm. The arm ratios of all the chromosomes were larger than 2. The karyotypes were of Stebbins＇s 2B type. The karyotypes of Melastoma were reported for the frst time.