African Journal of Biotechnology Vol. 6 (2), pp. 131-136, 18 January 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Chromosome studies in Cashew (Anacardium occidentale L.)

Aliyu, O. M.¹* and Awopetu, J. A.²

¹Department of Plant Breeding, Cocoa Research Institute of Nigeria, P M B 5244, Ibadan, Nigeria.

²Department of Agronomy, University of Ilorin, P M B 1515, Ilorin, Nigeria.

*Corresponding author E-mail: walealiyu@mail.com.

Accepted 4 January, 2007

Despite the increased cultivation of cashew as a commodity crop in sub-Sahara Africa, Asia and South America there are few chromosome studies on it. The present study investigates number, structure and behavior of chromosome in cashew populations growing in Nigeria. Cytological examination of these populations revealed a diploid and haploid chromosomes of 2n = 42 and n = 21 respectively. The karyotypes were mostly symmetric, composed mainly of metacentric pairs and several sub-metacentrics. Similarity in the morphology, number and behavior of the chromosomes in the accessions from different populations or origin attests to the degree of genetic closeness of the selections. This probably indicates high potential for use as parents in the breeding and improvement of cashew with very limited cross-incompatibility barriers (free gene exchange). Polymorphism in chromosome number was not recorded among these cashew selections.

Key words: Anacardium, cashew, chromosome, karyotype.