How to Count Chromosomes in Three Cicer Species?

Genus Cicer belongs to the legume family which is known as Fabaceae. Its native distribution is across the Middle East and Asia. Genus Cicer includes many herbaceous and shrubby species but chickpea, scientifically known as Cicer arietinum is the only domesticated and cultivated specie of this genus¹.

Genus Cicer is categorized into four different sections i.e. Monocicer, chamaecicer, polycicer and Achanthocicer. This classification was purely done on the basis of morphological specifications and life cycle traits².

The section, Monocicer consists of annual species such as C. bijugum which is essential for breeders while Polycicer section comprised of perennial species such as; C. oxyodon and C. anatolicum. The C. bijugum plays a significant role in the crossing program because of having desirable characters like resistance to ascochyta blight, pod borer and botrytis grey mold.

Chromosome number in Cicer species can be generalized as 2n = 2x = 16, even though changeable numbers both for chickpea (2n = 2x = 14, 16, 24, 32, 33) as well as other wild Cicer species (2n = 14, 16, 24) have been reported but could not be verified by other workers^3,4.

Therefore, scientists decided to conduct a study to in order to verify the chromosome number of the different species of genus Cicer. For this purpose, three species Cicer bijugum, Cicer oxyodon and Cicer anatolicum were selected for Karyotype analysis. All species were diploid with 2n = 2x = 16 chromosomes and karyotypes of all species consist of metacentric chromosome pairs⁵.

Conclusively, considering the analysis of the chromosome numbers of the different species of Cicer, scientists found that the diploid number of chromosomes for the genus Cicer is 16. It has observed that some species of Cicer have two pairs of satellites chromosomes while only one pair of satellites chromosome was noticed in C. oxyodon⁶.

REFERENCES

1. Van Oss, R., S. Abbo, R. Eshed, A. Sherman and C.J. Coyne et al., 2015. Genetic relationship in Cicer sp. expose evidence for geneflow between the cultigen and its wild progenitor. PloS One.
2. Van der Maesen, L.J.G., 1972. Cicer L.: A Monograph of the Genus, with an Special Reference to the Chickpea (Cicer arietinum L.), its Ecology and Cultivation. In: Mededlingen Landbouwhogeschool, Veenmam, H. and Q. Zonen (Eds.). WHO Geschool, Wageningen, pp: 1-127.
3. Sohoo, M.S., D.S. Athwalet and S. Chandra, 1970. Colchicine induced polyploidy in chickpeas (Cicer arietinum L.). Theoret. Applied Genet., 40: 163-168.
4. Mercy, T., S.K. Kakar and J.B. Chowdhry, 1974. Cytological studies in three species of the genus Cicer. Cytologia, 39: 383-390.
5. Iyengar, N.K., 1939. Cytological investigations on the genus Cicer. Ann. Bot., 3: 271-305.
6. Hejazi, S.M.H., 2011. Karyological study on three Cicer L. species (Fabaceae) in Iran. Asian J. Cell Biol., 6: 97-104.