GENETICS OF GENETIC CONSERVATION .1. SAMPLE-SIZE WHEN COLLECTING GERMPLASM

A sample of about 172 plants, drawn at random from a population of a t arget species, is of sufficient size to conserve at a very high probab ility, all or very nearly all of the polymorphic genes that are segreg ating in the population, provided that their frequency is not less tha n 0.05, irrespective of whether the individuals of the species set all of their seed by self- or by cross-fertilisation or a mixture of both . When samples are taken from a number of populations, the size of the sample drawn from each need be no larger than 172 divided by the numb er of populations visited. It is pointed out that implementation of th is conclusion could lead to very considerable saving of resources in b oth the collection and storage of material in gene banks.