The role of genetics in mainstreaming the production of new and orphan crops to diversify food systems and support human nutrition.

Especially in low-income nations, new and orphan crops provide important opportunities to improve diet quality and the sustainability of food production, being rich in nutrients, capable of fitting into multiple niches in production systems, and relatively adapted to low-input conditions. The evolving space for these crops in production systems presents particular genetic improvement requirements that extensive gene pools are able to accommodate. Particular needs for genetic development identified in part with plant breeders relate to three areas of fundamental importance for addressing food production and human demographic trends and associated challenges, namely: facilitating integration into production systems; improving the processability of crop products; and reducing farm labour requirements. Here, we relate diverse involved target genes and crop development techniques. These techniques include transgressive methods that involve defining exemplar crop models for effective new and orphan crop improvement pathways. Research on new and orphan crops not only supports the genetic improvement of these crops, but they serve as important models for understanding crop evolutionary processes more broadly, guiding further major crop evolution. The bridging position of orphan crops between new and major crops provides unique opportunities for investigating genetic approaches for de novo domestications and major crop 'rewildings'.

Specific weight of barley grains is determined by traits affecting packing efficiency and by grain density.

BACKGROUND: Specific weight influences the market value of barley grain, and in malting barley a high specific weight is thought to result in an increased malt output. However, links between specific weight and malt output have not yet been established. We hypothesised that packing efficiency and grain density will each contribute to specific weight. These traits would have implications for the malting process, highlighting the need for understanding what grain traits contribute to specific weight, before we can predict its effect on malting performance and efficiency. RESULTS: We report that specific weight is a product of grain density and packing efficiency, in our study proportionally contributing 48.5% and 36.5% to variation in specific weight, respectively. We report that packing efficiency is determined by grain dimensions, and is negatively correlated with the sum of grain length and depth. Therefore shorter, thinner grains can result in an increased specific weight, which is likely to be detrimental for malting performance. We also demonstrate that among cultivars which have grains with contrasting size traits, the same specific weight can be achieved through differing grain densities. CONCLUSIONS: Our results demonstrate that both grain dimensions and grain density must be considered jointly to optimise specific weight, and that the relationship between specific weight and malting performance and efficiency needs to be carefully considered with respect to how a high specific weight is achieved. © 2018 Society of Chemical Industry.