摘要
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 chromosome behavors of pollen mother cells and somatic karyotypes of 10 species in Malus having 2n=34 were analyzed by the improved smear method and the wall degradation hypotonic method respectively. Data on chromosome pairing reveal that meiosis is normal in most of these and 17 I configurations occupy a dominant position. Nevertheless, such anomalies as precocious or delayed disjunction of some bivalents, occurrence of multivalents, heteromorphic bivalems and univalents, chromosome lagging and fragmentation, formation of micronuclei and unequal anaphasic sagregation were found occasionally in some species. In the kary-otypic constitution the majority of chromosomes are metacentric (m) and submetacentric(sm) chromosomes; and 1-2 subtelocentric(st) homologous chromosomes are always present. These karyotypes belong to 2A, 2B and 3B types. All species show heterozygous chromosomes to a certain degree. The results obtained provide evidence of allopolyploid origin in Malus. The mode of origin with X = 17 was discussed.
出处
《果树科学》
CSCD
北大核心
1994年第4期216-220,共5页
Journal of Fruit Science
基金
国家自然科学基金资助课题<3870444>
关键词
苹果属
染色体
行为
核型
二倍体
Malus
Chromosome behavior
Karyotype
Diploid
Chromosomal base number
