Floral ecology, floral visitors and breeding system of Gandharaj lemon (Citrus × limon L. Osbeck)

Abstract

We studied the floral ecology, floral visitors and breeding system of Citrus × limon in West Bengal, India. We calculated a coefficient of pollination deficit (D) and also estimated the values of ‘relative pollinator service (RPS)’ to determine primary polli nators of the plant species. The cultivar is fully self-compatible and produces protandric hermaphrodite flowers and male flowers with considerable amount of floral rewards. Several insects like honey bees, solitary bees, carpenter bees, flies and butterflies visited the flowers. Among those, primary pollinators were Halictus sp. and Nomia sp., and important secondary pollinators were Apis dorsata and Xylocopa fenestrata. Considering the visitors’ group, the cultivar is principally pollinated by solitary bees. Besides diverse floral visitors, the cultivar showed medium pollination deficit (D = 0.49) and resulting in low fruit-set. Furthermore, premature fruit abortion is also high in all pollination treatments which lead to a low fruit-set of this lemon variety in West Bengal. K e y w o r d s : pollination deficit, relative pollinator service, self-compatible, solitary bee