African Journal of Biotechnology Vol. 6 (2), pp. 137-142, 18 January 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Application of amplified fragment length polymorphism (AFLPs) for detection of sex–specific markers in dioecious Uapaca kirkiana Muell. Årg.

Weston F. Mwase^{1, 2}*, S.Erik-Lid¹, Å. Bjørnstad¹, B. Stedje³ , M.B. Kwapata² and J.M Bokosi²

¹Norwegian University of Life Sciences, Plant & Environmental Sciences Department, P.O. Box 5003, N-1432 Ås, Norway.

²University of Malawi, Forestry & Horticulture Department, Bunda College of Agriculture, P.O. Box 219, Lilongwe, Malawi.

³Natural History Museum, Botanical Garden, University of Oslo, P.O. Box 1172 Blindern NO-0318 Oslo, Norway.

*Corresponding author Email: westmwase@yahoo.co.uk

Accepted 14 December, 2006

Uapaca kirkiana Muell. Årg is a dioecious fruit tree species for priority domestication in Southern Africa. It reaches reproductive maturity in eight to ten years with male plants making up 50% of breeding populations. Early identification of sex of seedlings is a prerequisite for selection and tree improvement. The amplified fragment length polymorphism (AFLP) technique was used to amplify DNA segments of U. kirkiana male and female plants to identify sex-specific markers. A total of 84 selective primer combinations were screened using bulked segregant analysis (BSA) for males and females. More than 110 polymorphic markers were obtained but each of the four primer pairs (E-ACT/M-CTG, E-ACA/M-CAA, E41+A/M-CTA and E-AGG/M-CTC) showed one band that was linked to sex. When the four primer pairs were tested in ten individuals from different populations only one primer pair (E-ACT/M-CTG) amplified a 320 bp band in female plants only. It is possible that this marker is linked to a sex-determining locus. The results suggest that the gene that determines sex of U. kirkiana is autosomal in nature and this marker may be important during fruit domestication and tree improvement programmes. The marker has been sequenced and sequence characterised amplified region (SCAR) marker will be developed and used for precise and rapid identification of female plants.

Key words: AFLP, bulked segregant analysis, dioecious, domestication, SCAR, sex determination, Uapaca kirkiana.