黄瓜四个品种的核型分析及其倍性变化的研究

KARYOTYPE STUDIES AND OBSERVATION ON PLOID VARIATION IN FOUR CUCUMBER CULTIVARS(CUCUMIS SATIVUS L.)

摘要: 本文对黄瓜的四个不同品种(“津一号”、“津二号”、“津四号”和“一串连”)进行了核型及倍性变化的研究,染色体数目为2n=14,其染色体组成为2n=2x=14=14m(2SAT)均为中部着丝点染色体,每一品种只有一对随体染色体,“津一号”和“津二号”还具有一个次级缢痕。黄瓜体细胞倍性的变化有3n、4n和6n,随着细胞倍性增高,其多倍性细胞频率依次下降,不同品种倍性的变化以“津四号”为最高,“一串连”品种为最低。

Abstract: The karyotype of somatic chromosomes is 2n=14=14m(2SAT). All chromosomes are metacentric in all the four cultivars studied, with only one pair of satellite chromosomes in each cultivar. Two cultivars have one secondary constriction. Three ploid levels of somatic cells, 3n, 4n, and 6n are found. The higher is the ploid level, the lower is the frequency of polyploid cells. The number of polyploid cells varies with cultivars. The causes of morphological and ploid variation in cucumber chromosomes are discussed.