ABSTRACT: Reduction of pesticide use in crops is now becoming an urgent concern, and implementation of biological control are issues to achieve this goal. Biological control against insect pests is now used in many crops as a control strategy replacing in most cases the use of insecticides. It can be achieved either by releasing of natural enemies, or by biodiversity conservation. Farmers are more and more aware of the important role that natural enemies may play on the control of crop pests. However, the absence of any actual quantification of the potential influence of natural enemies on grape-moths and aphids population dynamics (the most damaging pests in grape and cereal crops respectively) reduced until now the inclusion of natural enemies activity in management decisions. The present project PARADe focus on biodiversity conservation scoping on efficient parasitoids that occurs in these major crops, cereals and grapes. It involves two important INRA research units, two French Agronomy high schools (Agrocampus West and Bordeaux National School of Agricultural Sciences), two technical national structures (ARVALIS and French Vine and Vine Institute), two ‘extension services (Chambres d’Agriculture) and two important grape producer cooperatives. Originally, the two agrosystems are considered together in developing decision tools based on identical philosophy: assessing the occurrence of such parasitoids in the two crops and developing decision support tools to assist farmers in the development of agroecological pest management strategies. We thus want to predict the risk of reaching the threshold currently indicated to farmers to trigger insecticide treatment, based on the level of infestation of the plot and the rate of parasitism at the beginning of population development. These objectives will be based on the use of recently identified molecular tools able to detect with a fine accuracy, the occurrence of parasitoids in the two main pests of cereals (aphids) and grapes (grape-moths). These molecular tools will be used early in season to evaluate the damage on next insect generations and then to assist the decision ‘treating or not treating’. Non-academic and academic partners of this project will work closely to the process of model development and transfer to final users: technical papers, presentations and training sessions to growers and to cooperatives and structural adjustment of the teaching and pedagogical practices in order to integrate this innovation into academic training.

With the shift towards a reduced reliance on external inputs in agriculture, identifying management options that enhance the provision of ecosystem services has become a critical issue. Pest control resulting from the activity of naturally present predators and parasitoids is frequently cited as an important service that could reduce pesticide use as targeted by the French 2018 Ecophyto governmental action. However, the link between management options, pest control level and ultimately crop yield is poorly understood. The PEERLESS project aims to identify alternative management strategies that enhance the crop protection service provided by functional biodiversity and ultimately to optimize agricultural systems, at local and landscape scales, for economic viability and sustainability. PEERLESS brings together six partners organisations with extensive expertise in agronomy, spatial ecology, ecology of interactions and public economy. The project combines: (i) an empirical assessment of naturally occurring crop protection from weed and insects pests in annual (wheat-oilseed rape rotations) and perennial (apple orchards) systems across a broad range of landscape and agronomic situations; (ii) ecological engineering with an assessment of alternative plant protection system to improve crop protection at the local scale; (iii) an in-depth study of the structure of trophic networks; and, (iv) population dynamics of key pests and their regulators in case study areas. These components will support the parametrisation of spatially-explicit, predictive models to (v) test the effect of landscape patterns of alternative local and landscape management strategies on pesticide use, pest control, crop yield and farmer income and (vi) identify landscape scale viable management strategies to control insect and weed pests.

Behavioural epidemiology studies the interaction between human behaviour and the spread of infectious diseases. Plant pathogens and their insect vectors are among the main threats to global food security. The methods used to control plant pathogens and their vectors must be ecologically-friendly and sustainable. To date, the few models that couple grower behaviour with plant disease epidemics do not address pathogen evolution. However, grower decisions impose new selection pressures on pathogens, which evolve and adapt to control methods. Grower decisions may concern several control methods including the use of disease-resistant varieties, roguing (i.e., removing) infected hosts, and the use of biocontrol agents against pathogens or their insect vectors. Our biological models include the Citrus greening disease (caused by vector-borne bacteria), and nematodes of potato and tomato. The objective of this project is to develop a theory of behavioural epidemiology specific to plant health, with an evolutionary perspective. More specifically, we will explore the key mechanisms allowing the adoption (or not) of control methods in sufficient proportion to maintain disease incidence under an acceptable level, taking pathogen evolution into account. Such control methods are often expensive, and we aim at assessing to what extent subsidising them would stabilise their use in order to maximise plant health in the long-run. The consortium gathered around this project brings together expertise in plant disease epidemiology, mathematics, computer sciences, and economics. The interdisciplinary nature of the project will lead to original research in the field of plant disease epidemiology and evolution. From an applied perspective, this project will help design policies to control plant diseases that consider the dynamic behaviour of growers as well as pathogen evolution. This research aims to develop plant protection methods respectful of people and their environment.

Global food security entails fertile soils capable of providing food for a growing population and also contributing to other needs such as energy, clothing, etc. However, soils also play a major role in flow regulation within the biosphere and host an important biodiversity underlying biological processes which contribute to overall ecosystem ecology and functioning. Sustainable management of cultivated soils must therefore combine provisioning ecosystem services to a web of supporting and regulation services. Such comprehensive management of soil ecosystem services (SES) is challenging due to the complexity of the positive or negative interactions between services and the difficulty to assess the impact of practices or management on these services. The main objective of the SOILSERV project is to combine biophysical and socio-economic approaches to assess at different spatial scales ecosystem services of agricultural soils and to analyze their economic valuation in farmers or public decisions. Within mixed agroecosystems involving crops, livestock production and uncultivated areas, SOILSERV aims at jointly evaluating provisioning (crop production), regulating (water quality, climate change, biodiversity conservation) and supporting (preservation of soil quality) ecosystem services and to study their interactions. The selected spatial scales correspond either to decision levels for agricultural practices (field, farm) and landscape management (the commune, set of farms) or to relevant scales in terms of biophysical processes (landscape, watershed). The project involves three research axes: (1) the biophysical assessment of SES at different spatial scales, by mobilizing and comparing descriptors derived from measures, modelling results or more easily accessible indicators; (2) the prediction at the required spatial scales of soil characteristics necessary to soil ecosystem services assessment, through innovative disaggregation and change of support approaches of existing soil spatial information; (3) the integration of soil-related information into farm management models and territory planning strategies in order to consider soil sustainability criteria into the decision-making process. By assembling a multidisciplinary academic team (agronomy, biogeochemistry, ecology, hydrology, pedology, spatial modelling and economy) with professional partners (consulting firm, metropolitan government), SOILSERV aims at clarifying the concepts and consolidate the methods of SES assessment, by identifying approaches best suited according to the target scale and available information. The joined biophysical evaluation of ecosystem services with their economic assessment within agricultural holdings and with territory planning procedures, intends to identify the social conditions and the potential impact on production and environment of a multi-SES strategy. In the end, SOILSERV aims at increasing the synergy between the ecosystem functioning and social organization of the territories, taking into account the complexity of the soils and associated uncertainties.

Meiotic recombination is a fundamental process for all sexual eukaryotes; it is required to produce balanced gametes and therefore is essential to the fertility of species. Furthermore, meiotic recombination is also crucial for plant breeding because it allows, through the formation of crossovers (COs), to reshuffle genetic material between individuals and between species. Major international efforts have been made to identify the genes that are involved in meiotic recombination in plants, primarily using diploid Arabidopsis thaliana as model system. Therefore much of this work has disregarded the consequences of polyploidy, one of the key features of crop plant genomes, on meiotic recombination. Essential questions thus remain unsolved: How is meiotic recombination regulated in polyploid (crop) species? Why and how does polyploidy increase the rate of meiotic recombination? How can such improved knowledge on recombination be exploited for crop improvement? This project will address these questions specifically, using two complementary polyploid crop species: oilseed rape (Brassica napus; AACC; 2n=38) and bread wheat (Triticum aestivum; AABBDD; 2n=42). We will set up a complete set of integrated analyses to explore many inter-related aspects of CO regulation in polyploid crops. Task 1 aims at characterizing the molecular underpinnings of CO suppression between homeologous chromosomes in wheat and oilseed rape. We will proceed with positional cloning of the PrBn (in oilseed rape) and Ph2 (in wheat) loci. For this latter case, particular emphasis will be placed on evaluating TaMSH7, the most promising candidate for Ph2. CROC will thus advance understanding of the mechanisms that hamper the incorporation of beneficial traits from wild relatives into crop plants by promoting a diploid-like meiosis in allopolyploids; overcoming this specific stumbling block would open the road to the creation of new crop varieties resistant to diseases and more efficient in nitrogen use (to name only these). Task 2 will advance understanding on the cause of the striking CO rate increase we have discovered in Brassica digenomic triploid AAC hybrid and its possible application to wheat. We will determine whether these extra COs i) arise from one or the other CO pathways and ii) can be combined with those resulting from the mutation of an anti-recombination meiotic protein. We will unravel the individual and interaction effects of three C chromosomes on the rate and distribution of COs between homologues and test whether wheat pentaploid AABBD hybrids have the same boosting effect on CO frequencies as Brassica AAC triploid hybrids. The expected outcomes will pave the way to broaden the genetic variation that is available to plant breeders. CROC is a timely project that is shaped to address fundamental questions with practical objectives; it is directly upstream of research on innovative plant breeding technologies contributing to the competitiveness of French/European Agriculture and thus completely relevant to this call. CROC combines a group of researchers with a comprehensive and complementary expertise and set of facilities. Its strong translational emphasis ensures that the results obtained will have general significance that extends beyond oilseed rape and bread wheat. Our work will thus shed new light on the pending cause of CO variation in polyploid plant species, a critical issue for genetics, evolution and plant breeding.