几种菊属植物及其种间杂种减数分裂行为观察

 对菊花脑〔D. nankingense ( 2x) 〕、甘菊〔D. lavandulifilium ( 2x) 〕、四倍体菊花脑〔D.nankingense (4x) 〕、‘滁菊’〔D. morifolium ‘Chuju’ (6x) 〕、‘黄英’〔D. morifolium ‘Huangying’ (6x) 〕及其部分种间杂种减数分裂过程染色体行为进行研究。结果表明: 二倍体的菊花脑和甘菊减数分裂中期Ⅰ(MⅠ) 每个花粉母细胞( PMC) 平均染色体配对构型分别为0.83Ⅰ + 8.58Ⅱ和1.50Ⅰ + 8.25Ⅱ; 四倍体菊花脑PMCMⅠ染色体配对构型为2.64Ⅰ + 13.35Ⅱ + 1.03Ⅲ + 0.93Ⅳ; 六倍体‘滁菊’和‘黄英’PMCMⅠ染色体配对构型分别为0.48Ⅰ + 26.09Ⅱ + 0.33Ⅳ和1.09Ⅰ + 25.18Ⅱ + 0.18Ⅲ + 0.50Ⅳ, 是两个已经二倍体化的异源六倍体。菊花脑×甘菊的杂种F₁ PMCMⅠ染色体配对构型为1.61Ⅰ + 8.19Ⅱ; 四倍体菊花脑×菊花脑、菊花脑×四倍体菊花脑杂种F₁ PMCMⅠ染色体配对构型分别为3.42Ⅰ + 8.34Ⅱ + 1.53Ⅲ +0.58Ⅳ和3.62Ⅰ + 8.31Ⅱ + 1.50 Ⅲ + 0.56Ⅳ; 菊花脑ב黄英’、‘黄英’ ×菊花脑和甘菊ב黄英’、‘黄英’ ×甘菊正反交杂种F₁ PMCMⅠ染色体配对构型分别为0.30Ⅰ + 16.45Ⅱ + 0.70Ⅳ、0.29Ⅰ + 16.07Ⅱ + 0.89Ⅳ、0.63Ⅰ + 16.32Ⅱ + 0.68Ⅳ和0.47Ⅰ + 16.38Ⅱ + 0.65Ⅳ + 0.03Ⅵ; 四倍体菊花脑ב滁菊’杂种F₁ PMCMⅠ染色体配对构型为3.59Ⅰ + 18.03Ⅱ + 0.98Ⅲ + 0.52Ⅳ + 0.07Ⅴ。由减数分裂行为可以看出菊花脑和甘菊亲缘关系较近, 菊花脑和甘菊及其近缘种可能是栽培菊花的1个染色体组供体; 菊属3个染色体组间分化程度较低, 彼此亲缘关系较近, 且部分染色体可能存在易位等结构变异, 或菊属内广泛存在促进配对的基因。

Research on Meiosis of Some Dendranthema Species and Their Hybrids

Meiosis behaviors of D. nankingense ( 2x) , D. lavandulifilium ( 2x) , D. nankingense(4x) , D. morifolium ‘Chuju’ (6x) , D. morifolium ‘Huangying’ (6x) and part of interspeicific hybrids between them were studied. The results were concluded as following: The chromosome pairing configuration in meiosis MI per PMC of diploid D. nankingens and D. lavandulifilium was 0.83Ⅰ + 8.58Ⅱ and 1.50Ⅰ+8.25Ⅱ, respectively. The chromosome pairing configuration in meiosis MⅠ per PMC of tetraploid D. nankingense (4x) was 2.64Ⅰ + 13.35Ⅱ + 1.03Ⅲ + 0.93Ⅳ. The chromosome pairing configuration in meiosis MⅠ per PMC of hexaploid D. morifolium ‘Chuju’and D. morifolium ‘Huangying’were 0.48Ⅰ + 26.09Ⅱ+ 0.33Ⅳ and 1.09Ⅰ + 25.18Ⅱ + 0.18Ⅲ + 0.50Ⅳ, respectively, which elucidated that they were two allohexaploids with diploidization meiotic behavior, as well, there were structural changes as translocation on somechromosomes. The chromosome pairing configuration in meiosis MⅠ per PMC of D. nankingense ×D. lavandulifilium was 1.61Ⅰ + 8.19Ⅱ. Chromosome configuration per PMC in MⅠ was 3.42Ⅰ + 8.34Ⅱ + 1.53Ⅲ+ 0.58Ⅳ in F₁ hybrids of D. nankingense (4x) ×D. nankingense (2x) and 3.62Ⅰ + 8.31Ⅱ + 1.50Ⅲ +0.56Ⅳ in that of D. nankingense (2x) ×D. nankingense (4x). Meiotic association per PMC in MⅠ of F₁ hybrids of D. nankingens ×D. morifolium ‘Huangying’, D. morifolium ‘Huangying’ ×D. nankingens,D. lavandulifilium ×D. morifolium ‘Huangying’and D. morifolium ‘Huangying’ ×D. lavandulifilium were 0.30Ⅰ + 16.45Ⅱ + 0.70Ⅳ, 0.29Ⅰ + 16.07Ⅱ + 0.89Ⅳ, 0.63Ⅰ + 16.32Ⅱ + 0.68Ⅳ and 0.47Ⅰ + 16.38Ⅱ + 0.65Ⅳ + 0.03Ⅵ, respectively. Chromosome configuration in meiosis MⅠ per PMC of F₁ hybrids of D. nankingense (4x) ×D. morifolium ‘Chuju’was 3.59Ⅰ + 18.03Ⅱ + 0.98 Ⅲ + 0.52Ⅳ + 0.07Ⅴ.The results indicated that the genetic relationship between D. nankingense and D. lavandulifilium was closely,and D. nankingense, D. lavandulifilium or some of their relatives were the pregenitor of one genome of cultivating chrysanthemum. The degree of differentiation of three genomes in genus Dendranthema was low and the homology of the three genomes was high. Meanwhile, Structural changes such as translocation were likely tohappen in some chromosomes, and pairing-promotion genes existed in genus Dendranthem a widely.