部分菊属植物及其种间杂种减数分裂异常现象观察

Primary study on abnormalities of meiosis in some species of Dendranthema and their hybrids

关键词:  菊属  种间杂种  减数分裂异常行为  染色体结构变异

Key words:  Dendranthema  interspecific hybrids  meiosis abnormalities  structural variation of chromosome

摘要:

对不同倍数性菊属植物及其部分种间杂种的减数分裂异常现象进行观察统计,并分析其形成机制以及在菊属系统演化中的作用。结果表明,菊属减数分裂异常现象包括分裂不同步、二价体提前解离、二价体互锁、染色体桥、落后染色体等。减数分裂不同步现象普遍存在于菊属植物减数分裂过程。二倍体的菊花脑、甘菊、异色菊的部分二价体在终变期提前解离为单价体。菊花脑及其部分杂种中观察到了互锁二价体。四倍体菊花脑、南京野菊、‘黄英'、‘滁菊'在AI和AII都出现了染色体桥,毛华菊有1.5%的PMC在AI出现染色体桥。四倍体菊花脑AI、AII期出现落后染色体的频率分别为10.6%和7.3%; 毛华菊AI期出现落后染色体的频率为4.4%; 栽培菊‘黄英'和‘滁菊'在AI、AII期出现落后染色体的频率高于毛华菊。杂种出现染色体桥及落后染色体的频率普遍高于亲本。倒位以及由其引起的各种染色体结构变异可能在菊属系统演化过程中起着重要作用。

Abstract:

The meiosis abnormalities phenomenon in Dendranthema and some of their hybrids were observed,and the formation mechanism also the role which played in the process of phylogenesis were analyzed. The results indicated that abnormalities of meiosis in Dendranthema comprised nonsynchronous division,bivalent disjunction,interlocking bivalent,chromosome bridge,lagged chromosome,fragment and so on. While more,meiotic nonsynchronous division is ubiquitous in the course of meiosis of Dendranthema,some bivalents disjuncted at diakinese in diploid species of D.nankingense,D.lavandulifilium,D.dichrum. Interlocking bivalent in D.nankingense and some of its hybrids were also observed. Chromosome bridge occurred in D.nankingense(4X),D.indicum,D.morifolium‘Huangying'and D.morifolium‘Chuju'at AII and AI.However,1.5% PMCs of D.vestitum had chromosome bridge only at AI. The frequency of lagged chromosome in D.nankingense(4X)was 10.6% and 7.3% respectively. The frequency of lagged chromosome in D.morifolium‘Huangying' and D.morifolium‘Chuju' at AII and AI were higher than that of D.vestitum,which was 4.4% only at AI. And the frequency of the chromosome bridge and lagged chromosome of parents was normally higher than that of their hybrids. There were genes that probably controlled the formation of structural variations such as chromosome inversion and translocation on some chromosomes might play important roles in the process of phylogenesis of Dendranthema.