Phylogenetic relationship between Colocasia and Alocasia based on molecular techniques

摘要

A taro strain collected in Nepal was considered to be an intergeneric hybrid between Alocasia and Colocasia, on the basis of chloroplast DNA analyses. In order to examine the possible occurrence of the intergeneric hybrid in nature, an artificial cross was attempted and numerous seeds were obtained after a cross between C. esculenta and A. brisbanensis. Most crossed seeds, however, did not germinate and consequently only a single plant was fully developed. Random amplified polymorphic DNA (RAPD) analyses of this seedling and its parental plants showed that this plant shared the polymorphic RAPD bands with both parents. This plant was triploid (2n=3x=42) and chromosome painting using genomic in situ hybridization (GISH) determined that 14 of 42 chromosomes were derived from A. brisbanensis. It was concluded that this plant was the intergeneric hybrid and was formed as an unreduced egg of C. esculenta was fertilized with normal A. brisbanensis pollen.