by Joanna Wolstenholme, Communications intern
A fascinating new paper by Beverly Glover’s group in the Department of Plant Sciences, University of Cambridge, has pulled together research on an area often overlooked: the role of pollinators in food security, and the potential of breeding crops to attract more pollinators. With 35% of global crop yield dependant on animal pollinators, and around 75% of the 115 highest producing crops world-wide benefitting from greater yields when pollinated by animals, it is clear that the role of pollinators is very important to food security, and an area that really should be considered when looking to select traits for breeding.
Bailes et al suggest three main ways to move towards maximising the role of pollinators in increasing yields: help to conserve the bees we already have, ensure pollen from current crops is available at times which help pollinators and then sustain this food source throughout the pollinator’s lifecycle, and breed for floral traits in crop plants which maximise the number of possible pollinators.
Wild bees have been shown to be important for fruit set in a variety of crops, independent of the actions of honey bees. This means that we must protect our wild bees, which have decreased in number thanks to changes in land use and habitat destruction – yet another example of the importance of conservation and biodiversity protection to food security.
The vast quantities of pollen produced by, say, a field of oilseed rape are an important food source for many pollinators. However, such resources are transient, and so other food sources must be available to help support any increase in pollinator number after the crop in question has finished flowering. Bailes et al suggest that this could be resolved by ‘complementing early flowering crops with late flowering crops in adjacent fields, or strips of semi-natural flower-rich vegetation, ensuring a stable foraging supply over a longer period’. Alternatively, crop flowering could be co-ordinated with key life cycle stages of pollinators by breeding for different flowering times.
Finally, the possibility of breeding for improved floral traits, which will attract a large number of a range of pollinators, is discussed. Floral traits are constantly evolving, and there is much evidence of the genetic basis for this. What is needed now is a conscious effort to think of pollinators in the breeding process, in order to apply this knowledge to crop plants. A range of traits can be maximised: nectar and pollen quantity and qualities; flower shape and colour, and scent.
Many of the points raised show huge potential for relatively easy implementation either into farming practices in the field, or when thinking about trait selection in breeding programmes. It is vital that we take note, and start to think not only of the standard traits such as yield, and drought and pest resistance, when it comes to breeding, but also pollinator attraction.