Pollination – its type, threats and role in environment conservation

Pollination is simply the transfer of pollen from the anther of one flower to the stigma of another or the same flower. After production of the sexual organs and associated structures, pollination is the first step in the reproductive process of higher plants. It is achieved by biotic and abiotic means. Abiotic pollination occurs by wind, water or gravity. Biotic pollination is effected by animals. Pollinating agents are essential for survival and reproduction of several wild plant species and in the recent years, there has been an increasing recognition of the importance of pollination, mostly by insects, in crop plants. The area covered by pollinator-dependent crops has increased by more than 300 per cent during the past 50 years. Few major crop species depend on animal pollinators. Animal pollination increases the quantity and quality of fruit production. Important Insect pollinators include honeybees, bumblebees, solitary bees, syrphid flies, wasps, beetles, butterfly and moths etc. Also commercially reared bumblebees are an important component of greenhouse tomato production. Plant-pollinator interaction in both wild and cultivated plant species is under threat as a result of indiscriminate pesticide use, habitat fragmentation and intensified cultivation practices. Pesticides are an important potential cause of biodiversity and pollinator decline. Climate change may affect the phenology and distribution ranges of both crop plants and their most important pollinators, leading to temporal and spatial mismatches. It is therefore important to identify the temperature sensitivity of the most important pollinators and their crop plants, and the environmental cues controlling the phenology and distribution of the identified species. Many wild plants in nature are being propagated through insect pollination which maintains the sustainability of ecosystems, environmental quality and help in the conservation of biodiversity. The pollinator species that do not visit crops play critical roles in natural ecosystems by ensuring wild plant seed and fruit set, thus sustaining wider biodiversity.