The collections for agronomical sciences can be classified in two broad categories: collections linked to plant protection and those devoted to the conservation of genetic resources

Conservation  of plant pathogens

Diseases due to plant pathogens and losses caused by crop pests are chief constraints for the production of food resources, timber and biomass, entailing major economic losses.

These pests display a wide diversity and a considerable adaptive potential. Modern agriculture, by narrowing the range of cultivated species and reducing within-species diversity, exerts a strong, homogenous selective pressure on pathogens. This pressure precipitates the development of new strains bypassing variety resistance or selects strains for their tolerance to pesticide application.

Understanding these adaptive dynamics is capital  to improve control means (breeding of new varieties and optimized management of  phytosanitary treatments)

It involves a good knowledge of pathogen and pest populations that builds on the characterization of large groups of isolates for their phenotypic (pathogenicity, etc.) and genetic (diversity of neutral or selected markers) characteristics. These approaches require using collections of hundreds of specimens, representative of the intraspecific diversity in a given species. In that respect, and also because the availability of living specimens is necessary for the study of their biological characteristics, these collections differ from those used for taxonomic studies.

For some plant pathogens, long-term conservation of stable specimens, or isolates, is achievable. These are collected across various geographical scales and different periods in contrasted contexts in order to gain knowledge on the structure and evolution of these populations. Isolate collections are thus continuously enhanced; collections of isolates responsible for past epidemics are enriched with isolates causing present epidemics or originating from newly contaminated zones.. 

In addition have been established collections of insect pathogens (bacteria, viruses) and parasitoids (entomopathogenic nematodes, micro-hymenoptera), used to study interaction mechanisms and to identify new ways of biocontrol.

Conservation of plant genetic resources

Plant genetic resources represent the diversity of genetic material encompassed in traditional and modern varieties, in material used by breeders and in wild species related to crops.

This diversity is an invaluable heritage whose conservation is a major strategic challenge for all activities connected to the living world.

Ex situ conservation is the most usual means to conserve these plant genetic resources, and also the most practical and reliable way to make them available to end-users. The local scientific community has extensive experience in managing outstanding crop collections (Cirad, IRD, Inra). These collections concern crops from temperate, Mediterranean and tropical zones. Most of them are organized as Biological Resource Centres (BRC). These are specialized facilities that acquire, conserve, study and disseminate collections of living specimens (seeds, etc.) or parts thereof (DNA banks, etc.) as well as the attached databases, under strict quality and traceability conditions. BRCs must fulfill the stringent quality and expertise criteria required by the international scientific community and the industry for the dissemination of information and biological material. They allow farmers as well as research/development programs in life sciences to access these biological resources. Several BRC are managed within the local scientific community: the Montpellier Tropical BRC, the Medicago and Grapevine BRCs.

A major initiative, supported by the Languedoc-Roussillon Region, aims to implement in Montpellier a world centre for the conservation and study of plant genetic resources. The Agropolis Resource Center for Crop Conservation, Adaptation and Diversity program will bring together at the same location equipment for conservation (cold rooms, cryopreservation, DNA bank), analysis (seed phenotyping, sequencing/ genotyping), research and training.

In addition, some research teams are working with a network of BRCs devoted to tropical crops (French West Indies, Guiana, Réunion).

Finally, although they are not plant genetic resources stricto sensu, we can mention here the collection of symbiotic bacteria  (rhizobia) strains from a wide range of tropical and Mediterranean legumes of agricultural and/or ecological interest.