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采用改良涂片法和去壁低渗法对苹果属10个二倍体种的小孢子母细胞染色体行为及根尖体细胞核对进行了分析.结果表明:小孢子染色体行为大多表现正常,联会构型以17Ⅱ占绝对优势.但偶尔也发现某些二价体的提早成延迟分离,多价体的发生,异型二价体、单价体、落后染色体及微核的形成以及后期的不均等分配;在体细胞染色体组成上,以中部着终点染色体(m)和近中都着丝点染色体(sm)为主,此外还有1—2个近端都着终点(st)同源染色体,核型为2A、2B和3B型.在每一种类的核型组成上均存在不同程度的染色体杂合现象.这些结果表明了苹果染色体组的异源多倍体起源,最后讨论了基数X=17的起源类型.
The chromosomal behavior and apical somatic cell nuclei of microspore mother cells of 10 diploids of apple genus were analyzed by modified smear method and wall-down osmosis method.The results showed that most of microspore chromosome behaviors were normal, The conformation is dominated by 17 ¢ ò, but the occasional early separation of some divalent species, the occurrence of multivalent species, the formation of heterodimeric, monovalent, lagging chromosomes and micronuclei, and the late unequal distribution are also found ; In the somatic cell chromosome composition, the end of the central chromosome (m) and near the centromere (sm) -based, in addition to 1-2 proximal end point (st) homologous chromosomes, nuclear Types 2A, 2B, and 3B, with heterozygous chromosome heterozygosity for each of these karyotypes.These results indicate the origin of allopolyploidy in the apple genome, and finally the radix X = 17 The origin of the type.