Showing papers by "Gérard Duc published in 2018"

Pulses for Sustainability: Breaking Agriculture and Food Sectors Out of Lock-In

Abstract: Crop diversification can improve the sustainability of Western agriculture In particular, pulses are crops that can help both agriculture and the food industry more ecological, as they reduce greenhouse gas emissions and offer opportunities to reduce animal-based food consumption However, the development of those crops in Europe remains locked-in by major crops that have been co-developed to a greater extent both in farming and food systems After recalling the major mechanisms that lead to this lock-in, this article proposes to adopt a co-evolution framework to tackle with a dual transition of both agriculture and food systems We question how the current societal trends in the agrifood system offer new opportunities for pulses, and how simultaneous changes both in production and consumption can occur to facilitate this dual transition Based on various insights from the literature, and some points of views from stakeholders in France - taken here as examples - we argue that to develop pulses, strong support is required from public institutions to coordinate and guide the multiple actors involved in the same direction

Co-inoculation of a pea core-collection with diverse Rhizobial strains shows competitiveness for nodulation and efficiency of nitrogen fixation are distinct traits in the interaction

Abstract: Pea forms symbiotic nodules with Rhizobium leguminosarum sv. viciae (Rlv). In the field, pea roots can be exposed to multiple compatible Rlv strains. Little is known about the mechanisms underlying the competitiveness for nodulation of Rlv strains and the ability of pea to choose between diverse compatible Rlv strains. The variability of pea-Rlv partner choice was investigated by co-inoculation with a mixture of five diverse Rlv strains of a 104-pea collection representative of the variability encountered in the genus Pisum. The nitrogen fixation efficiency conferred by each strain was determined in additional mono-inoculation experiments on a subset of 18 pea lines displaying contrasted Rlv choice. Differences in Rlv choice were observed within the pea collection according to their genetic or geographical diversities. The competitiveness for nodulation of a given pea-Rlv association evaluated in the multi-inoculated experiment was poorly correlated with its nitrogen fixation efficiency determined in mono-inoculation. Both plant and bacterial genetic determinants contribute to pea-Rlv partner choice. No evidence was found for co-selection of competitiveness for nodulation and nitrogen fixation efficiency. Plant and inoculant for an improved symbiotic association in the field must be selected not only on nitrogen fixation efficiency but also for competitiveness for nodulation.

Comparative Genome-Wide-Association Mapping Identifies Common Loci Controlling Root System Architecture and Resistance to Aphanomyces euteiches in Pea

Abstract: Combining plant genetic resistance with architectural traits that are unfavorable to disease development is a promising strategy for reducing epidemics. However, few studies have identified root system architecture (RSA) traits with the potential to limit root disease development. Pea is a major cultivated legume worldwide and has a wide level of natural genetic variability for plant architecture. The root pathogen Aphanomyces euteiches is a major limiting factor of pea crop yield. This study aimed to increase the knowledge on the diversity of loci and candidate genes controlling RSA traits in pea and identify RSA genetic loci associated with resistance to A. euteiches which could be combined with resistance QTL in breeding. A comparative genome wide association (GWA) study of plant architecture and resistance to A. euteiches was conducted at the young plant stage in a collection of 266 pea lines contrasted for both traits. The collection was genotyped using 14,157 SNP markers from recent pea genomic resources. It was phenotyped for ten root, shoot and overall plant architecture traits, as well as three disease resistance traits in controlled conditions, using image analysis. We identified a total of 75 short-size genomic intervals significantly associated with plant architecture and overlapping with 46 previously detected QTL. The major consistent intervals included plant shoot architecture or flowering genes (PsLE, PsTFL1) with putative pleiotropic effects on root architecture. A total of 11 genomic intervals were significantly associated with resistance to A. euteiches confirming several consistent previously identified major QTL. One significant SNP, mapped to the major QTL Ae-Ps7.6, was associated with both resistance and RSA traits. At this marker, the resistance-enhancing allele was associated with an increased total root projected area, in accordance with the correlation observed between resistance and larger root systems in the collection. Seven additional intervals associated with plant architecture overlapped with GWA intervals previously identified for resistance to A. euteiches. This study provides innovative results about genetic interdependency of root disease resistance and RSA inheritance. It identifies pea lines, QTL, closely-linked markers and candidate genes for marker-assisted-selection of RSA loci to reduce Aphanomyces root rot severity in future pea varieties.

Diversité des agricultures – le cas des filières céréales, oléagineux et légumineuses à graines

Abstract: The objective of this article is to describe, without being exhaustive, the diversity of agriculture through examples of cropping systems and cultural practices, for metropolitan France and for three crop production sectors: cereals, oilseeds and legumes. The analysis of the diversity reveals ways of diversification of technical systems and cultural practices, that are strongly dependent on the diversity of added values of the sectors. With a few notable exceptions, the recommendations on the practices are vast enough to allow a diversity of cropping and farming systems, once the technological criteria of the sector have been met. Then, it is worth considering the weighting allocated to these technological criteria on the technical choices of the farmers. It also seems necessary to question the value given to the diversity by the various actors, from farmers to consumers, by estimating, in particular, the economic performance of the most diversified agricultural systems as well as the levers to increase the performances of a diversified agriculture. To strengthen resilience, it seems necessary to widen the core of knowledge on which the actors can devise new forms of diversity and to open the debate on the agricultural diversity.

David Bond and Jean Picard: Two pivotal breeders of faba bean in the 20th century

Abstract: David Bond and Jean Picard, two leaders of European legume breeding, died within a few months of each other. On the basis of their agronomic and genetic training, they both met the challenge of breeding faba bean, a protein-rich species that had received little attention from breeders before the 1950s (Picard, 1953; Bond 1957). Both made great strides at modernizing their chosen crop by developing and applying new ideas and techniques, as well as generating new methods and genetic materials.