Studying the cytological behavior of twenty seven cowpea (Vigna unguiculata L.) accessions to select new promising ones which could be used in cowpea breeding programs were carried out in the present investigation. All tested cowpea accessions exhibited the same normal chromosome number 2n = 22. The means of mitotic index (MI) were significantly different among most of studied accessions and some accessions exhibited high variability in the percentage values of mitotic stages. From all tested cowpea accessions, few of them showed high frequency of total mitotic chromosomal aberrations. Various types of mitotic abnormalities such as; lagging chromosomes, chromosomal bridges, outside chromosome, stickiness and micronuclei have been observed in all tested accessions. The cytological findings revealed that most of tested cowpea accessions had a potential cytological stability with normal chromosomal number 2n=22 and could be considered as good basic tools in cowpea breeding programs.
Key wards: Cowpea, Mitotic index, Mitotic aberrations, Plant breeding