Analysis of sampling strategies for collecting genetic material1

Abstract

A study was made using the data obtained during a 1973 expedition to collect wheat in Sicily in order to determine possible sampling strategies for collecting genetic resource material. Based on these analyses tables have been developed for selecting optimum sample sizes depending on relative cost and variance component considerations.

It is almost impossible to make a general recommendation for optimum sampling strategy. Variation may be (andprobably is) different in diverse areas, thus what is true in Sicily may not be true for Ethiopia, etc. Also sampling strategy should be different for characters which are inherited quantitatively from those which are controlled by one or two genes. Visual selection will reduce quantitative genetic variation and thus will defeat the primary purpose of collecting geneticresource material, which is to preserve as much genetic variation as possible. On the other hand, all collectors intuitively collect forms which seem new or unusual to them. Certainly when collecting for specific characters, such as disease resistance, dwarf growth type, stem strength, etc., collectors will not resort to random sampling. Many of the traits are rare and only large samples will ensure that genes responsible for these traits will be represented in the collection.