Potential of interspecific hybrids in the genus Asparagus.

摘要

To construct the phylogenetic tree of Asparagus species, we used 18 species under 3 subgenera (Asparagus, Myrsiphyllum and Protasparagus) and sequenced approximately 250 bp of internal transcribed spacer 1 (ITS1). Phylogenetic analysis indicated that the species of subgenus Asparagus consists of a monophyletic group, whereas the species of subgenus Protasparagus comprises a potentially paraphyletic assemblage. The results also showed that garden asparagus (A. officinalis) and A. schoberioides were closely related in the subgenus Asparagus, and A. densiflorus was placed at the most basal position in the genus Asparagus. Genetic distances among these species are probably correlated with the possibility to generate interspecific hybrids. We crossed A. officinalis, A. asparagoides, A. cochinchinensis, A. densiflorus, A. krausianus, A. schoberioides, A. virgatus and A. verticillatus, but only crossing between A. officinalis and A. schoberioides, and between A. officinalis and A. kiusianus gave interspecific hybrid plants. The correlation between the phylogenetic relationship among Asparagus species and the potential for interspecific hybridization with garden asparagus is described.