Key issues facing genebanks in preserving crop genetic diversity ex situ: overview of the range of challenges

This chapter reviews the key issues and challenges facing genebanks in preserving crop genetic diversity ex situ. Local crop genetic diversity is challenged with changes in land use, urbanization, land degradation, changes in agricultural practises, availability of improved varieties, changes in market preference, and the impact of climate change. Efforts have been made to secure plant genetic resources ex situ for future use but there are significant issues related to cost effective, efficient, secure, rational, and sustainable long-term ex situ conservation. It begins by addressing issues for the composition of ex situ collections and moves on to discuss issues for routine operations for conservation. The chapter also highlights issues for the use of conserved genetic resources, before concluding with a summary of why the development of sustainable genebank systems is so important.

Improving the global exchange of germplasm for crop breeding

Different norms, rules and practices organize the exchange of germplasm to address broader global challenges such as advancement of science and innovation, food security, sustainable agriculture or global equity. Some of these institutions are now embedded in various treaties and national regulations. This chapter claims that these regulations are not as successful as they could be because they fail to effectively integrate the complexity of the exchange environment. In order to better understand how exchange could be improved, it is important to go beyond a legalistic approach to exchange and look at the broader socio-technical context in which these exchanges take place. By developing an analytical framework that includes several dimensions beyond the regulatory one, this contribution creates the foundation for a more comprehensive approach that acts upon the relationship between germplasm and the diversity of institutional logics, germplasm and its resource system, and germplasm and its social environment.

Techniques and key issues in collecting crop wild relatives

The genetic diversity found in populations of crop wild relatives is an essential resource for future crop breeding, but populations are at risk of loss before germplasm has been fully conserved in genebanks. This chapter describes best practice for targeting and identifying species, and review knowledge about the variation in wild plant populations to guide the timing of collecting and approaches for genetic sampling. Indicators are presented for seed quality, ripeness and dispersal. Techniques for collection of seed, herbarium vouchers and associated data are reviewed with examples drawn from the Adapting Agriculture to Climate Change (Crop Wild Relative) project. Further research is needed to find optimal approaches for handling of seed to ensure high longevity of seed collections, and improved tools are needed to guide sampling of genetic diversity of crop wild relatives.

Plant genetic resources for food and agriculture for sustainable development

Plant genetic resources for food and agriculture, a common concern of all countries, are critically important for the sustainable production of the significantly more nutritious food needed to feed an ever-growing population in the face of climate change and other drivers. This entails the translation of the potentials encoded into their genetic blueprints into improved productivities. The relevant international agreements, instruments and mechanisms, which address the conservation, sustainable use and access and benefit-sharing for these resources, are reviewed along with their remarkable contributions to food security and nutrition. The chapter also highlights the state-of-the-art for the scientific and technological methods used to conserve and add value through genetic gains to these resources. Underscoring the importance of collaborations at various scales, we call for continued global coordination and partnerships on the internationally agreed activities for conserving effectively and deriving the most benefits sustainably from these irreplaceable resources.

Key steps in conservation and use of plant genetic resources: an overview

This chapter reviews the key steps in conservation and the use of plant genetic diversity. It begins by providing an example of a model which includes a series of steps starting with the full range of genetic diversity for all the target plant taxa, through the prioritisation of target taxa, the planning and the implementation of conservation action, leading through characterisation and evaluation, and utilisation in the development of novel crop varieties by farmers and/or breeders. The chapter then goes on to discuss conservation planning which is then followed by a review of the different strategies and techniques that are used in conservation. A section on the link between conservation and utilization is also included, before providing a conclusion that emphasises the importance of maintaining the current wealth of natural plant diversity.

Participatory plant breeding programs to optimize use of crop genetic resources

This chapter summarizes a sample of variety evaluation, experimental design, and breeding method innovations that have served as solid approaches for participatory plant breeding (PPB) efforts. With success in PPB comes success in conservation at a local level of useful alleles and allele assemblages in the form of on-farm crop genetic resources. PPB programs of this sort have the potential to add value to local or traditional varieties that might otherwise be abandoned, thus promoting their in situ conservation. This chapter briefly touches on methodologies to assess farmers’ variety preferences. This is followed by sections that highlight some experimental designs for on-farm variety evaluation and farmer-participatory breeding methods for combining in-situ conservation with genetic improvement. Finally, some of the challenges that may limit genetic gain from PPB programs are noted – problems that increase the risk of wholesale replacement of on-farm genetic diversity rather than conservation through improvement.

DNA-based screening of Brassica germplasm for sustainable and enhanced crop production

The Brassica genus contains many agriculturally important oilseed and vegetable crops. Brassica germplasm, including natural accessions and breeding populations, are maintained globally for sustainable management and enhancement of Brassica crop production which is critical to meet the demands of population growth and challenges of environmental stresses due to global climate change. DNA based markers, such as SNPs, are commonly used to screen large numbers of Brassica germplasm for conservation, genetic mapping and association studies. This chapter focuses on the application of SNP genotyping technologies for conservation of Brassica germplasm, uncovering the genetic basis of various biotic and abiotic stresses and screening for yield related traits and oil quality through marker-trait association studies.

Monitoring plant genetic resources for food and agriculture

This chapter reviews the methodologies developed to assess the extent of diversity of PGRFA at species, variety, and genetic level and examines the efforts made at global level in monitoring them at different scales. Efforts have been made to halt the loss of biodiversity (including genetic diversity) by United Nations Organizations (FAO, UNEP, UN) at setting of global targets (second Global Plan of Action on conservation and sustainable use of PGRFA, Aichi Targets and Sustainable Development Goals) and indicators have been established to monitor progress towards them. Yet none of the targets on genetic diversity have been achieved, due to a lack of implementable monitoring system that would allow progress to be accurately monitored. Further research is needed to improve the methodologies for monitoring plant genetic resources, particularly at the varietal and genetic level. The chapter discusses the opportunities and challenges as well as provides recommendations for future conservation and monitoring strategies that may safeguard PGRFA for posterity.

Community-based conservation of crop genetic resources

This chapter explores the current state of research, knowledge and practice of community-based conservation in the context of continued farmer-driven processes and the emergence of diverse external interventions. Autonomous community-based conservation is largely powered by farmer demand for crop diversity. Cultural, provisioning and regulating ecosystem services play an essential role. It is argued that an enhanced understanding of the drivers and rationales influencing farmers decision-making continues to be essential under the current scenario of accelerated global change. A large and diverse portfolio of exogenous interventions have emerged since on-farm conservation has become a development issue. A variety of different interventions designed to support on-farm conservation for are reviewed. This chapter also highlights the need for an effective monitoring framework for community-based management of crop genetic resources. Such a systems could enhance the measurement, metrics and intelligence underlying the on-farm conservation status of crops and landraces.

Seed systems and diversity

Farmers use various seed systems to obtain seeds for their next crop. The diversity of seeds determines, together with other aspects of the farming system, the biodiversity in farmed areas. Conservation strategies for crop genetic resources distinguish ex situ, on-farm and in situ components. The on-farm management of such resources is highly influenced by the seed systems that farmers use. Next to primary and secondary centres of diversity, this chapter introduces a tertiary source of diversity, based on the creation of new diversity through modern breeding. The impact of different seed systems on the management of crop genetic diversity is also analysed.