Dwarf hybrids of the bioenergy crop Ricinus communis suitable for mechanized harvesting reveal differences in morpho-physiological characteristics and seed metabolic profiles

Ricinus communis , also known as castor bean or castor plant, is a crop that produces seeds containing non-edible oil used widely in the chemical industry and the bioenergy sector. Varieties or hybrids that are suitable for mechanized harvesting may diminish the production cost boosting large scale production of the crop in new areas. In this study, we describe extensively the morphological characteristics and the ex situ performance of four newly developed R. communis hybrids (H11, H12, H13, and H14) focusing on plant architecture in order to facilitate mechanized harvesting. In addition, hybrid germination rate at low and optimal temperature was evaluated aiming to determine a minimal temperature requirement for early spring sowing in temperate climates. Seed metabolic profiling using LC–MS/MS analysis revealed the presence of more than 60 different primary and secondary metabolites, at varied levels in each hybrid, including amino acids, fatty acids, flavonols, flavones, flavanones, phenyl propanoids and catecholamines such as dopamine, many of which are reported for the first time in this species.