Pigeonpea (Cajanus cajan), a widely farmed diploid legume species.  It is an important reference genome for food crop development as many crop species, such as soybean (Glycine max), chickpea (Cicer arietinum), lentil (Lens culinaris), and alfalfa (Medicago sativa), are legumes. pigeonpea is the second most important pulse crop in India, has an average crop productivity of 780 kg/ha. The relatively low crop yields may be attributed to non-availability of improved cultivars, poor crop husbandry and exposure to a number of biotic and abiotic stresses in pigeonpea growing regions.  The genetic improvement of pigeonpea has ramifications for food protection as well, as it is cultivated primarily in small-scale holdings in semi-arid tropical regions of the developing world.


Microsatellites, also known as Simple Sequence Repeats (SSRs) or short tandem repeats (STRs), are repeating sequences of specific DNA which contains mono-, di-, tri-, or tetra-, penta- or hexa- tandem repeats such as (A)n, (CA)n, (GA)n, (GTA)n, (ATT)n, (GATA)n, (ATTTT)n, (ACGTCG)n. Genomes are scattered with these repeats. Repeats of longer units form minisatellites or satellite DNA. With the discovery of tandem iterations of simple sequence motifs, the term microsatellites was further coined.