ABSTRACT
Our major natural resources, soil, water, air, and light, are complemented by a fth equally important resource, that is, plant and animal germplasm, for the production of food and ber. Plants utilize soil, water, air, and light to produce organic matter to sustain animal life, including humans. Although we need to nurture all our natural resources, this chapter focuses on the conservation of germplasm related to crop plants. In plant breeding, two types of genetic progress impact production agriculture. The rst type of genetic progress involves incremental gains for qualitative (plant architecture, quality, and physiology) and quantitative (yield) traits. These gains are stable and may evolve in response to crop adaptation to mechanization, changing agronomic practices, or end uses. The second type of trait, such as pest resistance or the as-yet-unseen, new threats and environmental constraints, such as global warming, experience boom or bust cycles. For example, when a widely deployed resistance is overcome by a new race of a pathogen, we experience disease epidemics and crop busts. Abiotic stress caused by unpredictable weather, such as drought or heat, can lead to crop failure. Therefore, the need for new traits is ever increasing, immediate and long term, and requires the expenditure of nite genetic resources. The world’s food security will depend on the efcient management of global crop genetic resources, both in situ and ex situ.
