Deviating chromosome numbers in Asclepiadaceae

Abstract

The most common base chromosome number in the Asclepiadaceae is x = 11. Deviating base chromosome numbers have been found in the genera Cynanchum, Microloma, and Sarcostemma. An account is also given of previously published deviating chromosome numbers in the Asclepiadaceae.

What is the subtribe Glossonematinae (Apocynaceae: Asclepiadoideae)? A phylogenetic study based on cpDNA spacer

“…B. Pentarrhinum insipidum , 2 n = 24 (Voucher for B: Liede & Newton 3225, UBT). C. Pentarrhinum insipidum , 2 n = 22 (Voucher: Liede 2940, UBT); photograph published in Albers et al (1993; fig. 3), there erroneously identified as ‘ Cynanchum virens ’).…”

“…96% of the over 600 species investigated (based on Albers & Meve, 2001; unpublished counts of Albers & Meve). The basic chromosome number of x = 11 is regarded as the primary condition in Apocynaceae as a whole (Van der Laan & Arends, 1985; Albers, Liede & Meve 1993). Decreasing basic chromosome numbers deviating from x = 11 occur rarely in Asclepiadoideae (e.g.…”

“…Decreasing basic chromosome numbers deviating from x = 11 occur rarely in Asclepiadoideae (e.g. x = 10 in Microloma , Funastrum ; Albers et al 1993) and so do increasing ones (e.g. x = 12 in Vincetoxicum Wolf, Pergularia, Heterostemma Wight & Arn.…”

Karyomorphological Studies in Wrightia tomentosa and W. tinctoria; Multipurpose Tree Species of Aravallis in South-East Rajasthan

“…Thus the basic number is reported to be xϭ11 and 10 confirming the previous reports available for various genera in this family. Besides xϭ10 and 11,xϭ6,8,9,12,16,18,20,21 and 23 have also been reported in this family (Laan and Arends 1985, Albers et al 1993, Albers and Meve 2001. Of these xϭ11 is considered to be primitive (Laan and Arends 1985), occurring in ca.…”

Myth and reality of the subtribe Astephaninae (Decne.) Schumann (Asclepiadaceae)

“…Most chromosome numbers are as yet unknown; Bhttia fruticulosum (Liede & Newton 2946) and members of Pentatropis (Biswas, 1955;Sarkar et al, 1973; Liede & Conrad 2749) have been counted, with 2n = 22 the common number in the Asclepiadaceae. The species of Microloma counted this far uniformly possess 2n= 20 (Albers, Liede & Meve, 1993). Because of the scarcity of information on this character, it has not been included in the matrix for cladistic analysis.…”