Multiple Origin of Amphidiploids in the Complex Species of Scilla scilloides , Asparagaceae

In the complex species of Scilla scilloides involving A and B genomes, an amphidiploid having AABB genome composition is a major one of the cytotypes and distributes throughout a growing area of the species. An origin of amphidiploids and whether amphidiploids generated in monophyly or polyphyly are unsolved. In three hybrids with defied combination of genomes a maternal inheritance of chloroplast genome was confirmed in this species. An analysis of matK sequence of chloroplast genome demonstrated that a maternal parent of all amphidiploids in Japan, Korea and Taiwan investigated was a Japanese B genome diploid (BB diploid). In the analysis of ITSland 5S rDNA of nuclear genome and genome sizes indicated that the paternal parent of amphidiploids was different between the amphidiploid from Japan and Korea, and the amphidiploid from Taiwan. The Japanese and Korean amphidiploids would be originated by a hybridization and subsequent polyploidization between the maternal parent of Japanese BB diploid and the paternal parent of Korean A genome diploid (AA diploid). Taiwanese amphidiploids were generated between the maternal parent of Japanese BB diploid and a paternal parent of AA diploid undiscovered. An event of generation of the amphidiploids in S. scilloides occurred at least twice in the different locations with the different parents.