Molecular Breeding for Improved Second Generation Bioenergy Crops

There is increasing urgency to develop and deploy sustainable sources of energy to reduce our global dependency on finite, high-carbon fossil fuels. Lignocellulosic feedstocks, used in power and liquid fuel generation, are valuable sources of non-food plant biomass. They are cultivated with minimal inputs on marginal or degraded lands to prevent competition with arable agriculture and offer significant potential for sustainable intensification (the improvement of yield without the necessity for additional inputs) through advanced molecular breeding. This article explores progress made in next generation sequencing, advanced genotyping, association genetics, and genetic modification in second generation bioenergy production. Using poplar as an exemplar where most progress has been made, a suite of target traits is also identified giving insight into possible routes for crop improvement and deployment in the immediate future.

TrendsSecond generation bioenergy feedstocks cultivated from non-food crops on marginal lands are widely held as a promising source of renewable and sustainable energy to help displace fossil fuels.A substantial yield gap exists for key bioenergy crops and this has held back their successful commercial deployment for reasons of economy and sustainability.Affordable advanced molecular breeding techniques have driven progress in food crops in recent years as next generation sequencing has dramatically reduced costs.Traits of interest for improvement in bioenergy include biomass yield, feedstock quality, drought tolerance, and pest resistance.Genotyping by sequencing, association genetics, and genetic modification are now beginning to be applied in second generation bioenergy species with a view to addressing these breeding targets.