Karyotypes in Ethiopian Aloe species (Xanthorrhoeaceae: Asphodeloideae)

TY - JOUR

T1 - Karyotypes in Ethiopian Aloe species (Xanthorrhoeaceae: Asphodeloideae)

AU - Fentaw, Eshetu

AU - Dagne, Kifle

AU - Rønsted, Nina

AU - Demissew, Sebsebe

AU - Grace, Olwen Megan

PY - 2013/12

Y1 - 2013/12

N2 - A cytogenetic survey of 17 species in the succulent-leaved genus Aloe L. (Xanthorrhoeaceae subfamily Asphodeloideae) in Ethiopia was undertaken towards a more complete genetic characterisation of the genus throughout its distribution in Africa, Arabia and Madagascar. Somatic metaphase chromosomes of all species studied showed the same diploid chromosome number of 2n = 14, consisting of four pairs of long and three pairs of short chromosomes. Symmetry was characterised as Stebbins type 2B and the asymmetry indices AsK%, TF%, A1 and A2 revealed minor karyotypic variation common in closely related species. The metrics showed that A. benishangulana has a marginally higher degree of asymmetry than is typical, and the pubescent-flowered A. trichosantha has a more symmetrical karyotype than most other species. We suggest that the stable karyotype morphology in Aloe indicates that structural genome changes and ecological factors play a more prominent role in speciation in Aloe.

AB - A cytogenetic survey of 17 species in the succulent-leaved genus Aloe L. (Xanthorrhoeaceae subfamily Asphodeloideae) in Ethiopia was undertaken towards a more complete genetic characterisation of the genus throughout its distribution in Africa, Arabia and Madagascar. Somatic metaphase chromosomes of all species studied showed the same diploid chromosome number of 2n = 14, consisting of four pairs of long and three pairs of short chromosomes. Symmetry was characterised as Stebbins type 2B and the asymmetry indices AsK%, TF%, A1 and A2 revealed minor karyotypic variation common in closely related species. The metrics showed that A. benishangulana has a marginally higher degree of asymmetry than is typical, and the pubescent-flowered A. trichosantha has a more symmetrical karyotype than most other species. We suggest that the stable karyotype morphology in Aloe indicates that structural genome changes and ecological factors play a more prominent role in speciation in Aloe.

U2 - 10.1007/s12225-013-9475-8

DO - 10.1007/s12225-013-9475-8

M3 - Journal article

SN - 0075-5974

VL - 68

SP - 599

EP - 607

JO - Kew Bulletin

JF - Kew Bulletin

IS - 4

ER -