菊属与亚菊属属间杂种的鉴定及其分类学意义

Intergeneric hybrid of Dendranthema×grandiflorum "Aoyunhuoju" and Ajania pacifica and its taxonomic implications

通过有性杂交的方法获得了栽培菊花"奥运火炬"Dendranthema×grandiflorum"Aoyunhuoju"和亚菊属Ajania矶菊A.pacifica的属间杂种。形态学、细胞学以及RAPD分子标记鉴定表明22个杂种为真正的属间杂种,成功地将矶菊的某些性状(叶色)转移到栽培菊花中,但同时也掺入了某些不良性状。杂种的叶色、叶形、花色、开花枝的分枝性和花期等性状均介于双亲之间,边缘舌状雌花大小、数量和形态不一;杂种根尖染色体数目正常(2n=72),花粉母细胞减数分裂基本正常。矶菊与栽培菊花属间杂交的成功以及杂种减数分裂染色体行为正常表明两者亲缘关系较近,从而推测菊属Dendranthema与亚菊属之间的亲缘关系可能较近。

An intergeneric cross was made between Dendranthema×grandiflorum ＂Aoyunhuoju＂ and Ajania pacifica. Twenty two individuals were identified as an intergeneric hybrid according to the morphologies, cytogenetical characteristics and random amplification of polymorphic DNA （RAPD） molecular marker. Specific characteristics of A. pacifica, such as leaf color, were successfully integrated into the chrysanthemum cultivar, as were some less appealing morphological characteristics. Characteristics of the intergeneric hybrid, including leaf color, shape of leaf, color of flower, branching and blooming date, were intermediate between parents. However, the size, number, and shape of ray florets varied from individual to individual. Additionally, the chromosome number of the intergeneric hybrid was normal with an expected 2n=72; meiosis behavior overall was normal too. Cross compatibility indicated relative phylogenetic relationships between the parents to some extent. The intergeneric hybrid of D. ×grandiflorum ＂Aoyunhuoju＂ and A. pacifica and its normal chromosome behavior, as a result of the relatively high cross compatibility, suggested a close relationship between the parents. We supposed that a close relationship between Dendrathema and Ajania.