• 作者： 吳大本
• 作者服務機構： 臺灣大學植物學系
• 中文摘要： Para-sorghum 亞屬內 Sorghum nitidum 和 S. versicolor 的外部形態不同，但二者的粗絲期核型頗相似，又該二物種相互不能雜交，且二者地理分佈互異，本文根據此等訊識探討該二物種相互之親緣關係。 S. nitidum 和 S.versicolor 的染色體交叉頻度差異顯著，藉此細胞特徵，有助於識別此二物種。本研究尚分析出 Para-sorghum 亞屬內另一物種 S. purpureo-sericeum之核仁染色體，知其形態和長度皆與 S. nitidum 和 S. versicolor之核仁染色體頗相似，但前者具次末端核仁組成體，而後二物種具末端核仁組成體。
• 英文摘要： In morphological comparison, the awn length, sessile spikelet size, pediceled spikelet sex and rhizo-matous character appear to be the outstanding morphological characters distinguishing S. nitidum fromS. versicolor, both belonging to subgenus Para-sorghum. Pachytene analysis and comparison between thesetwo species indicate that their karyotypes are essentially similar. None of the attempts to obtain an inter-specific hybrid between these two species has been successful. Moreover，it is shown that they are isolatedfrom each other geographically. Based on these morphological, cytological, breeding and geographicaldata, the phylogenetic relationships between them are discussed. The phenomenon of a low mean number of chiasmata in S. nitidum and a higher value for S. versi-color was noticed at diakinesis and was considered to be a reliable cytological criterion distinguishing thesetwo species. The pachytene chromosomes of one other species of Para-sorghum, S. purpureo-sericeum, were alsoanalyzed here. The results of this analysis showed that the general appearance of nucleolus-associatedchromosomes in this species is similar to those in S. nitidum and S. versicolor, but the position of thenucleolus-organizing region differs from them: in S. purpureo-sericeum, it is subterminal; in S. nitidum andS. versicolor, terminal.
• 中文關鍵字： --
• 英文關鍵字： --