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

Abstract

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.