Diversity of pollinators and their role in the pollination biology of chickpea, Cicer arietinum L. (Fabaceae)

Chickpea (Cicer arietinum L.) is an important source of food for people worldwide. In the current study, we studied its pollination biology with special reference to floral visitors along with their visitation rate, frequency and pollen load during 2012 and 2013. We also explored the effect of floral visitors on the capsule weight, seed weight, seed numbers and seed germination. Results revealed three bees, two wasps, five flies, one moth and three butterfly species on the flowers of chickpea. Apis dorsata, A. florea, Amegilla sp. and Eristalinus aeneus were the major species with 434–474, 223–311, 69–74 and 81–136 individuals, respectively in both years. Floral visitors differed significantly in term of visitation frequency with A. florea as the most frequent visitor (9.13–9.86 visits/flower/5 min) followed by E. aeneus (5.43–5.58 visits/flower/5 min) and A. dorsata (1.72–2.31 visits/flower/5 min) in both years. Similarly, A. florea had statistically highest visitation rate (16.85–19.99 flowers visited/min) followed by E. aeneus (9.73–10.68 flowers visited/min). A. dorsata had significantly higher pollen load on its body (84629–85,104 pollen grains) followed by A. florea (64940–65,135 pollen grains) and Amegilla sp. (64020–65,120 pollen grains). The open-pollinated flowers had significantly higher capsule weight (0.27 ± 0.01 g), seed weight (0.18 ± 0.01 g), seed numbers (1.67 ± 0.07 seeds) and seed germination (95 ± 1.38%) as compared to flowers deprived of pollinators in cages. The results suggested A. florea, A. dorsata and E. aeneus could be effective pollinators of chickpea. Hence these three species can be properly utilized on commercial scale to increase crop yield.