Chromosome analyses in African Crinum species (Amaryllidaceae)

Abstract

The karyotypes were analyzed in populations of Crinum zeylanicum (L.) L. (2n = 22 and 30, 3n = 33), C. macowanii Bak. (2n = 22, 3n = 33, 4n = 44), C. jagus (Thomps.) Dandy (2n = 22), C. glaucum A. Chev. (2n= 22), C. purpurascens Herb. (2n= 22) and C. natans Bak. (2n = 22) from tropical Africa. The genus shows interesting karyotype evolution lines. In C. zeylanicum the new basic number x = 15 instead of x = 11 was found. This new basic number is believed to be derived from a hybrid population with 2n = 32 chromosomes by centric fusion, giving specimens with 2n = 30 chromosomes. At the other diploid level (2n = 22) all populations, except for one had karyotypes different from the usual Crinum scheme found in C. jagus, C. glaucum, C. purpurascens and C. nalans. Triploids with 3n = 33 chromosomes in C. zeylanicum were autotriploids as shown by both mitotic and meiotic studies, whereas tetraploids in C. macowanii appeared to be allotetraploids. In this species facultative apomixis is present. A hypothetical evolution scheme based on the different cytotypes found is presented. © 1979 Mendelian Society of Lund