Cicer arietinum is a self-polliated diploid (2n=2x= 16) with a relatively small genome of 740 Mb.

Chromosome number in Cicer species can be generalized as 2n=2x= 16, although varying numbers both for chickpea (2n= 2x= 14, 16, 24, 32, 33) and other wild Cicer species (2n=14, 16, 24) have been reported, but could not be confirmed by other workers.

Studies on biosystematic relations between chickpea and its wild relatives following interspecific hybridization have been limited to the 9 annual species,
C. arietinum (chickpea),
C. reticulatum,
C. echinispermum,
C. judaicum,
C.pinnatifidum,
C. bijugum,
C. cuneatum,
C. chorassanicum, and
C. yamashitae.

Based on the crossability and morphological similarities, the 9 annual species have been classified into 4 groups: the above first 3 species as group 1, the next 3 species along with C. yamashitae as group 2, and the remaining 2 species as two separate groups.

Of these, only two species, C. reticulatum and C. echinospermum produced viable hybrids with chickpea. Gene exchange, is normal between chickpea and C. reticulatum, while it is restricted due to high sterility in the hybrids involving C. echinospermum.

In general morphology, physiology, and genetics, C. reticulatum comes closest to the cultigen, making it a possible progenitor of chickpea. However, considering the polymorphic nature of ancestral populations and complex nature of domestication, one can not rule out the other possibilities, such as C. reticulatum and the cultigen sharing a common ancestor or a polyphyletic origin of chickpea.