Hostname: page-component-848d4c4894-2pzkn Total loading time: 0 Render date: 2024-05-23T13:55:59.429Z Has data issue: false hasContentIssue false

Variation in chromosome number in the Manuleae (Scrophulariaceae) and its cytotaxonomic implications

Published online by Cambridge University Press:  26 April 2010

K. Jong
Affiliation:
Royal Botanic Garden Edinburgh; Department of Plant and Soil Science, University of Aberdeen, Scotland.
Get access

Abstract

Chromosome numbers for 11 genera and 36 species in the predominantly South African tribe Manuleae (Scrophulariaceae) are presented, the majority being first reports. The basic numbers of the genera form a dysploid series, x = 6, 7, 8, 9. The somatic number of most of the species is diploid, ranging from 2n = 12 to 2n = 18; that of Jamesbrittenia, 2n = 24, is probably of polyploid derivation. The highest somatic number encountered in this survey is that in Camptoloma lyperiiflorum, with 2n = c.56, which, taken in conjunction with a published count of 2n = 28 for another species of Camptoloma, is octoploid based on x = 7. This is the only example, so far, of intrageneric polyploidy in the Manuleae. The somatic number in certain genera appears to be constant over some subgeneric divisions (e.g. Jamesbrittenia, 2n = 24), but variable in others (e.g. Sutera, 2n = 12, 14). The variation in chromosome number observed in this study parallels and corroborates the redefinition of generic boundaries proposed by O. M. Hilliard. One species of Selago (in the tribe Selagineae) was also included in this survey for cytological comparison with Tetraselago (Manuleae).

Type
Articles
Copyright
Copyright © Trustees of the Royal Botanic Garden Edinburgh 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Bentham, G. (1836). Synopsis of the Buchnereae, a tribe of Scrophulariaceae. In: Hooker, W. J. (ed.) Companion to the Botanical Magazine 1: 356384.Google Scholar
Bentham, G. (1846). Scrophulariaceae. In: de Candolle, A. P. (ed.) Prodromus systematis naturalis regni vegetabilis 10: 348367.Google Scholar
Bohkhovskikh, Z., Matvejeva, G.T. & Zakharyeva, O. (1969). Chromosome numbers of flowering plants. Izdalelorstvo, ‘Nauka‘, Leningrad.Google Scholar
Borgen, L. (1969). Chromosome number of vascular plants from the Canary Islands, with special reference to the occurrence of polyploidy. Nytt Mag. Bot. 16: 81121.Google Scholar
Conger, A.D. & Fairchild, L.M. (1953). A quick-freeze method for making smear slides permanent. Stain Technol. 28: 281283.CrossRefGoogle ScholarPubMed
Fox, D.P. (1969). Some characteristics of the cold hydrolysis technique for staining plant tissues by the Feulgen reaction. J. Histochem. Cytochem. 17: 266272.CrossRefGoogle ScholarPubMed
Hedberg, O. (1970). The genus Zaluzianskya F.W. Schmidt (Scrophulariaceae) found in Tropical East Africa. Bot. Not. 123: 512517.Google Scholar
Hilliard, O. M. (1989). New genera, species and combinations in Scrophulariaceae—Manuleae. Notes Roy. Bot. Gard. Edinburgh 45: 481491.Google Scholar
Hilliard, O. M. (1992). New names and combinations in Jamesbrittenia (Scrophulariaceae— Manuleae). Edinb. J. Bot. 49: 225233.CrossRefGoogle Scholar
Hilliard, O. M. (1994). The Manuleae. A Tribe of Scrophulariaceae. Edinburgh University Press (in press).Google Scholar
Hilliard, O. M. & Burtt, B. L. (1977). Notes on some plants of Southern Africa chiefly from Natal: VI. Notes Roy. Bot. Gard. Edinburgh 35: 155177.Google Scholar
Hilliard, O. M. & Burtt, B. L. (1983). Zaluzianskya (Scrophulariaceae) in South Eastern Africa and the correct application of the names Z. capensis and Z. maritima. Notes Roy. Bot. Gard. Edinburgh 41: 143.Google Scholar
Jong, K. (1989). The cytology of Diascia (Scrophulariaceae). I. Chromosome numbers in section Racemosae. Notes Roy. Bot. Gard. Edinburgh 45: 559568.Google Scholar
Junell, S. (1961). Ovarian morphology and taxonomical position of Selagineae. Svensk Bot. Tidskr. 55: 168192.Google Scholar
Nordenstam, B. (1969). Chromosome studies on South African vascular plants. Bot. Not. 122: 398–408.Google Scholar
Sutton, D. A. (1988). A revision of the Tribe Antirrhineae. Oxford University Press, London and Oxford.Google Scholar