Field Gene Banks and Clonal Repositories

Abstract

Many horticultural species are either difficult or impossible to conserve as seeds because they produce recalcitrant seeds or reproduce vegetatively. Hence, they should be conserved as live plants in Field Gene Banks (FGB). FGBs provide an opportunity for easy and ready access to conserved material for research and utilization. Plant genetic resources conservation in FGBs helps not only in their conservation but also in their characterization, evaluation and utilization. Conservation in FGBs is required because alternative conservation methods are not fully developed for many plant species. There are pros and cons in conserving a species in an FGB. The advantages are that accessions are readily available for characterization, evaluation, use and exchange. Some disadvantages are that the accessions in an FGB are exposed to vagaries of nature (flood, drought, earthquake, etc.), disease and pests. Vegetatively propagated crops are maintained in clonal repositories as well. In the absence of seed production, clones are propagated and maintained in the form of trees, roots, tubers, corms, etc., and in FGBs. Although clonal repositories need less space, are easy to manage and cost-effective, FGBs are needed for maintaining genetic diversity. During the 1980s, procedures were developed for the maintenance of germplasm collections in FGBs. Bioversity International (formerly IPGRI) proposed guidelines for FGB establishment and the FAO released gene bank standards that cover good practices, including those for FGBs. Although there are no specific research needs, there are many ways in which FGBs can be made more effective, and some of these are discussed here. This chapter is concerned with the different aspects of FGB establishment and how to conserve accession with FGB, with specific examples.