Variation and evolution in the karyotype of Lycoris, Amaryllidaceae. VII. Modes of karyotype alteration within species and probable trend of karyotype evolution in the genus.

Genome Differentiation in Lycoris Species (Amaryllidaceae) Identified by Genomic in situ Hybridization

“…That is, L. incarnata is an allotriploid species derived from the fusion of normal reduced gametes of a species with 6M + 10T and unreduced gametes of a species with 22A or 20A + 1M′ + 1m. M′ and m type chromosomes of Lycoris are considered to have been formed by Robertsonian fusion of two long arms and two short arms of two A type chromosomes (Kurita 1988). The results of GISH also suggested that the M′ and m type chromosomes were derived from A type chromosomes.…”

“…Whenever required, M′ (small metacentrics) and m (very small metacentrics) were added to these major types (Kurita 1988).…”

“…Kurita (1988) also reported that T and A type chromosomes were likely to be derived through structural alterations of M type chromosomes. Based on the results of karyotype analyses and the examination of the geographical distribution and fertility in many accessions, Kurita (1988) suggested that genomes composed of M and T type chromosomes, such as in the case of L. longituba (6M + 10T), were ancestral and that genomes composed entirely of A type chromosomes, such as in the case of L. sprengeri (22A), were derivatives. Moreover, Lycoris incarnata was reported to be an allotriploid species (Kurita 1987, Hsu et al 1994.…”

“…In earlier studies (Inariyama 1932, 1951, Koyama 1954, Takemura 1961, 1962a, 1962b, two types of V-shaped (metacentrics) and I-shaped (telocentrics and acrocentrics) chromosomes were reported for karyotype classification, and a specific homology was observed between V + I and I types in their cross-compatibility and meiotic behavior. Kurita (1986Kurita ( , 1988 reported the major types of chromosomes [M (metacentrics), T (telocentrics) and A (acrocentrics)] and mutant chromosomes [M′ (small metacentrics) and m (very small metacentrics)] for classifying karyotypes in the genus Lycoris. Kurita (1988) also reported that T and A type chromosomes were likely to be derived through structural alterations of M type chromosomes.…”

“…Kurita (1986Kurita ( , 1988 reported the major types of chromosomes [M (metacentrics), T (telocentrics) and A (acrocentrics)] and mutant chromosomes [M′ (small metacentrics) and m (very small metacentrics)] for classifying karyotypes in the genus Lycoris. Kurita (1988) also reported that T and A type chromosomes were likely to be derived through structural alterations of M type chromosomes. Based on the results of karyotype analyses and the examination of the geographical distribution and fertility in many accessions, Kurita (1988) suggested that genomes composed of M and T type chromosomes, such as in the case of L. longituba (6M + 10T), were ancestral and that genomes composed entirely of A type chromosomes, such as in the case of L. sprengeri (22A), were derivatives.…”