Abstract

A detailed Karyotypic and meiotic study in three species of Chlorophytum is presented and its significance is discussed in the light of the modern concepts. Chlorophytum elatum R. Br. is tetraploid with 2n=28 chromosomes, C. heynei Baker. and C. laxum Baker. are diploids with 2n=14 or 16 chromosomes, in x=7 and 8 basic number lines and C. elatum shows asymmetrical karyotype while C. heynei and C. laxum show symmetrical karyotypes. Karyomorphological studies reveal some minor differences between the three species, such as absolute chromosomal length and relative length which clearly indicate a common origin and close relationship of these three species. However, populations of Chlorophytum elatum, C. heynei and C. laxum vary slightly in their intraspecific cytomorphological characteristics which may be the basis of ecotypic differentiation. The behaviour of chromosomes during meiosis in all the 3 species is found to be fairly normal. Nevertheless, in C. elatum quadrivalent association of chromosomes, laggards and bridges are of common occurrence. The presence of B-chromosome in C. elatum is recorded for the first time.

中文摘要

本文詳細報導三種吊蘭屬的核型及體細胞分裂的研究，且藉現代學理以討論其意義。彈絲吊蘭是四倍體，染色體為2n=28。赫氏吊蘭及小花吊蘭是雙倍體，染色體兼具2n=14 及16，而基數為7及8。彈絲吊蘭表現不對稱核型，而赫氏吊蘭及小花吊蘭則表現對稱核型。三種間之核型形態稍異，例如染色體絕對及相對長度明示此三種為同緣及親緣極相近。但此三種之族群內之細胞型特徵均稍異而顯示具有生態型分化現象。細胞分裂中之染色體行為在三種均為正常。但彈絲吊蘭常見染色體為四價，遲滯及橋之現象。B－染色體出現於彈絲吊蘭為首次之報告。

Keyword: Asphodeleae, Cytology, Chlorophytum elatum, Chlorophytum heynei, Chlorophytum laxum, Liliaceae.