Sampling strategy for genetic diversity
遗传多样性的取样策略

An appropriate sampling method not only serves as a prerequisite for conservation and utilization of biodiversity occurring in nature, but also affects the results of population genetic research. A strategic sampling method for genetic diversity can be defined as the optimum sampling method to achieve representation of the full genetic variation represented in a species or a population within a manageable number of samples. Therefore, strategic sampling must consider two factors: 1) the number of samples (including number of populations in a given area and number of individuals within a given population), and 2) the methods of sampling in relation to the genetic structure of the populations under consideration. The well-known Hardy-Weinberg Equilibrium and other principles of population genetics provide the theoretical bases of sampling strategy design. The theoretical models of sampling based on the Hardy-Weinberg Equilibrium offer a general guideline for the number of individuals to be sampled within a population and the number of populations to be sampled in a given region if there is no detailed genetic and environmental information available. Based on this, approximately 30 individuals from a population could be considered as a recommended size for collection under such conditions. When designing a sampling strategy, the biotic and abiotic factors that can influence the genetic diversity captured in the organisms under study should also be considered. The taxonomic status, life cycle, geographical distribution, breeding system, and environmental heterogeneity of a target species will significantly affect the pattern of genetic variation and consequently the design of sampling strategy. In general, the optimum sampling strategy should be designed on the basis of the biological features of the target species, environmental conditions, and objectives for conservation, utilization, or research.