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.

Floral biology, breeding system and pollination ecology of Justicia betonica L. (Acanthaceae): An assessment of its low reproductive success in West Bengal, India

“…We also calculated the relative pollinator service (RPS) for each floral visitor (Layek et al, 2020) as follows: where RA denotes the relative abundance of flower‐visiting species i , VR denotes the species' flower visitation rate, and PE i denotes the visitor species' single‐visit PE i . Based on the RPS values, we classified the floral visitors into four categories: (1) primary pollinators (RPS > 20%), (2) important secondary pollinators (10% < RPS ≤ 20%), (3) secondary pollinators (0 < RPS ≤ 10%) and (4) non‐pollinator (RPS = 0).…”

“…To judge whether the plant species face pollen transfer limitations in nature or not, we calculated the value for “coefficient of pollination deficit ( D )” by slight modification of the method of Layek et al (2020) as follows: where Ro is the reproductive success (i.e., percentages of fruit or seed set) in open‐pollination treatment, and Rs is the reproductive success in supplementary pollination treatment. Here, we considered the percentages of fruit set to calculate the D value.…”

“…where Ws and Wo refer to the percentage of the fruit set (or seed set) in self (here geitonogamy) and cross-pollination, respectively. To judge whether the plant species face pollen transfer limitations in nature or not, we calculated the value for "coefficient of pollination deficit (D)" by slight modification of the method of Layek et al (2020) as follows:…”

“…A high value of PEi of a floral visitor implies a high pollination efficiency (in a single visit) of the visitor species. We also calculated the relative pollinator service (RPS) for each floral visitor (Layek et al, 2020) as follows:…”

Supplemental Stingless Bee Pollination in Fennel (Foeniculum vulgare Mill.): An Assessment of Impacts on Native Pollinators and Crop Yield

“…After obtaining the data of fruit set in open-pollination and manual cross-pollination treatments, we measured a coefficient of pollination deficit (D) by using the method of Layek et al (2020bLayek et al ( , 2021b as follows:…”