A Review of Perceptual Distinctiveness in Landraces Including an Analysis of How Its Roles Have Been Overlooked in Plant Breeding for Low-Input Farming Systems

A Review of Perceptual Distinctiveness in Landraces Including an Analysis of How Its Roles Have Been Overlooked in Plant Breeding for Low-Input Farming Systems. Traits providing perceptual distinctiveness (PD), which allow less commercial farmers in developing countries to recognize and name individual landraces, enable the creation and management of their diversity and the transfer of knowledge of each to other farmers and succeeding generations. Worldwide examples illustrate how PD traits on seeds and vegetative propagules help maintain genetic purity and provide markers at planting time, identifying landraces suitable for planting at particular locations and times and for future household and market needs. PD traits on the yield also enable household members and customers to identify and value landraces for different uses. To fulfill these roles, they are generally highly salient, restricted in number, environment-independent, qualitatively inherited, generally with expression based on one or a few genes, and often culturally significant. Even so, they are seldom mentioned as varietal selection criteria by farmers, who may be unaware of their importance, or in plant breeding programs and in situ conservation of plant genetic resources projects; the need for national variety release committees and policymakers in developing countries to include them is emphasized.