The objective of seed conservation is to preserve the genetic integrity of the seed under controlled conditions. For this, representative seed samples of the natural populations are stored, i.e., the gene frequency of the sample must be equal to that of the original population. The storage conditions should be such that the seed should be kept viable for the longest possible time. This chapter deals on how to store seeds of crops and wild plant species for medium- and long-term conservation because seed conservation in gene banks remains the most efficient method for conserving plant germplasm of the cultigen and their wild relatives. The arrangements taken for preserving seeds are given herein considering particularly at what happens at various gene banks elsewhere. The focus of this chapter is seed conservation in gene banks.

Humans have used plants in numerous ways to meet their multiple needs since the early days of our existence. Plant use ranges from their indirect use for recreational, health and amenity purposes to their direct use as food, medicines and as a source of useful variation for plant breeding and crop improvement. Traditional and Indigenous cultures have relied on the use of plants for many thousands of years, whereas commercial exploitation is more recent. Ethnobotany is the study of the relationship that exists between people and their use and knowledge of plants. Economic botany is also a term often used to describe how people have and continue to use and exploit plants. For certain plant species a number of factors have contributed to their overexploitation. The same 2016 State of the World’s Plants also points out that over 30,000 plants are now protected under CITES, the global convention on trade in endangered species. For other plant species and varieties many remain neglected and underutilized and there are many socio-economic, political and technical barriers preventing their sustainable conservation and utilization. The purpose of plant genetic conservation is to make plants and plant-derived products available for sustainable utilization.

This chapter provides an overview of genetic diversity and variation and how to measure this when studying plant genetic resources. It also describes the use of DNA markers for assessing polymorphism, studying diversity and revealing trait associations relevant for searching variation of target characters in plant breeding. The goal of this chapter is therefore to highlight various methods for analyzing the range of genetic diversity and of character variation to facilitate their further use in plant breeding. The information given herein will allow to understand genetic diversity, gene polymorphism and genetic variation; assess how various techniques – based on population and quantitative genetics – are used for assessing genetic diversity and trait variation in plant germplasm; and determine how the data generated can be effectively analyzed.

This chapter will look at the role of both field gene banks and living collections in botanical gardens and arboreta in ex situ conservation of plant diversity. In vitro conservation techniques are increasingly used for the conservation of vegetatively propagated species (e.g. potato, cassava, yam, taro, sweet potato, etc.) and species with recalcitrant seeds (e.g. apples, coconut, cocoa, coffee, oil palm, etc.), or even species that rarely produce seed (e.g. garlic, banana). The methodology takes explants (small pieces) from the whole plant, most appropriately the plant’s meristems, and places them in sterile culture, pathogen-free environment, for storage and subsequent use. In recent years there have been various refinements of the basic techniques to enhance storage, such as storage at ultra-low temperatures (cryopreservation) or the storage of samples of DNA and pollen. However, there are limitations to these techniques, such as genetic instability of plant material stored in tissue culture or the difficulty of regenerating whole plants from stored DNA and pollen.

An introduction and overview to the subject of biological diversity (biodiversity) is provided, and more specifically the systematic conservation and sustainable utilization of plant genetic diversity. The copious wealth of plant diversity provides the primary production to feed us all and among which we live is threatened by human mismanagement; plant diversity at the habitat, species and genetic levels is threatened to a degree never seen previously in our planet’s history.This chapter illustrates the range of plant diversity at the habitat, species and genetic levels, where plants are found and reviews the threats it currently faces. Also, the importance of genetic diversity is emphasized, why we need it and how it can be used to provide food security and other ecosystem services.The strategies and techniques used to conserve plant diversity are defined and the concept of complementary conservation is introduced.The chapter also provides an overview of the ways humankind exploits and utilizes plant diversity.

Plant genetic conservation ensures the genetic variation held within species is maintained and remains available for use.Population genetics is that branch of genetics studying the factors determining, maintaining and changing variation in populations. The main subject of study relates to factors affecting changes in allele frequency and how population genetic knowledge can be used to improve the effectiveness of the sampling of diversity conserved either in gene banks or other ex situ facilities or in situ in genetic reserves or on-farm. This chapter describes the theory underpinning population genetics and how to use this knowledge for providing a sound and effective strategy and ensuing plan of work for collecting, conserving and using plant genetic diversity.

Following the Green Revolution, conventional, ‘scientific’ plant-breeding quickly became the dominant breeding paradigm. However, conventional breeding has failed some farmers, particularly those in marginal agricultural environments. This conventional approach has been increasingly challenged by more collaborative approaches to breeding which bring farmers, scientists, extension officers and other actors together in decision-making. These approaches are commonly referred to as participatory plant breeding and participatory varietal selection. Such participatory approaches to plant breeding offer opportunities to better involve farmers and communities in the breeding process and to better target and meet their needs.This chapter will review and discuss, with the help of case studies from all over the world, both the principles of participatory plant breeding and participatory varietal selection, as well as the advantages and disadvantage of the participatory approach compared to the conventional approach to plant breeding.

Fungi have co-existed with animals and plants throughout the whole of the evolutionary time since these three groups of higher organisms originally separated from one another. Living together closely for this length of time has given rise to many cooperative ventures. We have already seen how many fungi have combined with plants as partners in mutually beneficial relationships such as mycorrhizas and lichens. In these symbiotic, or mutualistic, associations the partners each gain something from the partnership so that the association is more successful than either organism alone. The organisms concerned (often two but sometimes more) live in such close proximity to each other that their cells may intermingle and may even contribute to the formation of joint tissues, as they do in the lichen thallus, which is one of the most ancient mutualistic associations of all and found in some of the most inhospitable environments.