池杉染色体核型的分析

<正> 前言 池杉(Taxodium ascendens Brongn.)别名池柏,是杉科(Cupressaceae)落羽杉属(Taxodium)的高大乔木,生长快,材质好,抗性强,树型美,为良好的用材和造园树种。 池杉原产北美,本世纪初引入我国江苏南京、南通、上海和河南鸡公山等地。三十年代扩种到武汉、江西庐山、广州等地。解放后,池杉的分布区迅速扩大,长江南北各省广泛栽

KARYOTYPE ANALYSIS OF TAXODIUM ASCENDENS BRONGN

Taxodium asccndens Brongn. ( Taxodiaceae), a timber tree native to North America, was probably introduced to China at the beginning cf this century. It is nowadays widely cultivated on both sides cf the Changjiang ( Yangtze)River.A kary-ctypical analysis cf the species was investigated for the first time, and the num-ter of chrcmcscmes in grewing tip cell of thcot was fcur.d to be 22 = 2B, rgreeing with these reported ty Stebbins for Taxcdinm distichum(L.)Rich., Mehra and Khoshoo for T.mucronatum Ten., and Hizume and Tanak'a for Taxodium in general, except for the presence of two B-chrcmosomes. According to the terminology defined by Levan et al. ,the karyotype formula is therefore 2n = 24 = 22m +2B(m). Photomicrographs of the chromosome complements and idiogram of the karyotype are given in Fig. 1 and 2 respectively.Measurements in microns of chromosomes are given in Table 1 .The occurrence cf B-chrcmosomes in Taxodium asccndcns is probably due to changes in environmental conditions since its introduction into China.