Confirmation of jumping genes controlling pod colour in pigeonpea (Cajanus cajan L.)

Presence of jumping genes or transposon elements controlling pod colour in pigeonpea has not been reported so far. Here, we observed three pod colour variants including streaked (parental type), partially streaked, and no streaks (green) in 19 individual plants of a germplasm accession, ICP 3773. We did not find any definite pattern with respect to their place of origin on the plants. Further, the study of pod colour patterns in the progenies of 19 plants suggested that this phenomenon could possibly involve a transposon (‘Ds’) and an activator (‘Ac’) gene to produce irregular variation in pod colour that otherwise remained unexplained on the basis of Mendelian genetic inheritance. The activated transposon was either copied or separated from its original chromosomal site and got inserted into the gene controlling pod colour. Such events mutated the pod colour gene(s) to completely or partially inhibit the production of normal parental type streaks on the pod surface.