Legume Seed Production Meeting Market Requirements and Economic Impacts

International audienceThe seed is the carrier of the genetic improvements brought about by modern plant breeding, and seed production is carried out in accordance with certification systems to guarantee consistent high quality. In forage legumes, breeding efforts are primarily related to the vegetative development of the plant, although the commercial success of an agronomically superior cultivar is dependent on a reliable supply of competitively priced seed. In seed production of the three most important forage legumes, alfalfa (Medicago sativa L.), white clover (Trifolium repens L.), and red clover (Trifolium pratense L.), crop management techniques are applied to stimulate reproductive development in order to obtain high seed yields. These include a low plant density, manipulation of canopy size to avoid lodging and shading of fruiting organs, synchronization of flowering with pollinating insects as well as controlling pests. High seed yield is correlated to inflorescence density and seed yield per inflorescence, traits which should be selected for in breeding populations as moderate to high heritability has been found. However, seed yield is a genetically complex trait and in the perennial, insect-pollinated forage legumes it is further highly influenced by environmental conditions and crop management factors. Further investigations into the use of plant growth regulators and an improved understanding of the interaction between pollinators and the seed crop might improve future seed yields. There is likely to be an increasing emphasis on the role of forage legumes in producing high-quality meat and milk, combined with the requirement to reduce the environmental footprint of grassland agriculture. A high forage legume seed yield is a prerequisite to meet market requirements for new, improved cultivars and hence achieve the economic impacts of modern plant breeding for a better livelihood and environment

Interaction of Metal Cations with Alkylnitriles in the Gas Phase: Solvation of Metal Ions by the Hydrocarbon Chain

Relative affinity measurements of monovalent metal ions (M=Li+, Na+, Cu+ and Ag+) toward aliphatic nitriles have been performed using the kinetic method by dissociation of metal-bound dimer ions of the type R1C equivalent to N-M+-N equivalent to CR2. It was found, particularly for Cu+ and Ag+, that the affinity toward nitriles having long chains (>C-6) is markedly enhanced. This is attributed to a bidentate interaction of the metal ion with the nitrile moiety and the aliphatic chain. Theoretical calculations on the copper complexes show that these bidentate structures enjoy about 30% greater copper-ion affinities compared to their linear counterparts. Such aliphatic interactions also play a major role in the dissociation chemistry of copper-bound tetramers of the kind (RC equivalent to N)(4)Cu2+center dot where the long aliphatic chain R curls around the copper ion to facilitate electron transfer or a redox reaction to produce (RC equivalent to N)(2)Cu+ + RC equivalent to N+center dot + RC equivalent to N