African Journal of Biotechnology Vol. 5 (22), pp. 2049-2052, 16 November 2006   

ISSN 1684–5315 © 2006 Academic Journals        

Full Length Research Paper

Somatic chromosome counts and yield performance of some accessions of ‘egusi’ melon (Citrullus lanatus)

E. O. Idehen¹*, O. B. Kehinde¹ and A. E. Adegbite²

¹Department of Plant Breeding and Seed Technology, Uni versity of Agriculture, P. M. B. 2240, Abeokuta, Nigeria

²Department of Biological Sciences Uni versity of Agriculture, P. M. B. 2240, Abeokuta, Nigeria.

*Corresponding author. E-mail: emmaidehen@yahoo.com.

Accepted 24 October, 2006

Abstract

Investigation in 20 accessions of Citrullus lanatus (‘egusi’ melon) revealed somatic chromosome counts ranging from 18 to 24 with 2n = 22 being the most frequent. Polyploid counts of 2n = 40 and 2n = 44 were made for accessions DD98/4 and L6, respectively. Diploid chromosome counts varying from 2n = 22 suggest aneuploid changes in chromosome number or can be attributed to counting difficulties caused by the overlapping of the sticky small chromosomes. The polyploid counts were exact multiples of the diploid numbers, suggesting occurrence of polyploid forms/cultivars of the species. The high yield performance observed for L6 as reflected in the fruit size and weight is a reflection of gigas effect that is characteristic of polyploid genomes. The study reveals that knowledge of chromosome counts and character expression will be useful in the selection of genotypes for hybridization purposes.

Key words: Chromosome, ‘egusi’ melon, diploid, aneuploid, polyploidy.