Bee pollination effects on yield and chemical composition of West Indian gherkin fruits (Cucumis anguria L., Cucurbitaceae) in the Brazilian semi-arid region

Abstract

Animal pollination plays a key role in global agricultural production and especially of monoecious crops, which are essentially dependent on pollinators. The West Indian gherkin fruit (Cucumis anguria L., Cucurbitaceae) is a monoecious vegetable adaptable to adverse abiotic conditions, resistant to diseases, and rich in minerals and vitamins, thus being a relevant alternative for improving nutritional security of socioeconomically vulnerable populations. The knowledge on the influence of pollination and of specific pollinators on chemical characteristics of fruits would help pollinators’ management, but it is still poorly understood. In this study we investigated the influence of pollination on quantitative and qualitative aspects of fruits fruits of West Indian gherkin fruits (Cucumis anguria L., Cucurbitaceae) in the Brazilian semi-arid region. Data on pollination biology and on fruits resulted from controlled crosses (open-OP, cross-CP and Apis mellifera Linnaeus, 1758 pollinations) were compared among crosses: number, length, weight, number of seeds, firmness and chemical traits related to flavor and shelf life. Flowers were pollinated by four bee species, and Apis mellifera was the most frequent. followed by two native bee species. OP and A. mellifera resulted in more fruits than CP. Fruits resulting from OP were heavier than CP and had similar weight when compared to A. mellifera. The other variables did not differ between treatments. The better performance of OP and A. mellifera when compared to CP is probably related to the xenia, i.e., the influence of tissues bearing paternal genes (pollen and pollen tube) in maternal tissues. OP and A. mellifera experiments apparently resulted in the deposition of a greater genotypic diversity of the pollen loads when compared to CP. This result is also explained by the higher functional diversity of pollinators related to OP when compared to CP. This study not only elucidates immediate impacts on yield but also emphasizes the deeper connections between floral biology, pollinator diversity, and sustainable crop production, once West Indian gherkin profit was enhanced by bee pollination.