【摘要】 香榧(Torreya grandis Fort.cv.Merrillii)是我国特有的经济树种,雌雄异株。根尖细胞染色体分析表明:雌株有一对异形性染色体,异配性别,属ZW型;雄株是同配性别,属ZZ型。雌株的核型为2n=2x=22=22m(2SAT+ZW),雄株的核型为2n=2x=22=22m(2SAT+ZZ)。雌株的体细胞中只有一条最短的Z染色体,间期核的两个染色中心的差异明显。雄株有一对最短的Z染色体,间期核的两个染色中心的大小相同。根据这些特征,植株的性别可早期鉴别。更多还原

【Abstract】 Chinese torreya (Torreya grandis Fort. cv.’Merrillii’) is an endemiceconomic tree species in our country, which is dioecious. The chromosomalanalyses of the cells in root tip, show that the female plant has a pair ofheteromorphic sex chromosomes, which are heterogametic sex and belong toZW type. The male plant is homogametic sex and belong to ZZ type. Thekaryotype of the female plant is 2n=2x=22=22m (2SAT+ZW), while thatof the male plant 2n=2x=22=22m(2SAT+ZZ) In the somatic cell of the female plant there is only one shortestz chromo-some, and the difference of the sizes between the two chromocentres of inter-phase nuclei is notable. The male plant has a pair of shortest Z chromosomesand the sizes of the chromocentres of interphase nuclei are the same. Accor-ding to these characters the sexuality of the plant can be discriminated atearly stage,更多还原