The biology of cereal land race populations

Evolutionary approaches in gene conservation are emphasized to be faced regardless of their complexities and immediate economic return. Such emphasis is mainly based on recovery of genes eroded, endemic balance of pathogen outbreak, and on provision of information on how a population of plants becomes adapted to different regions. However, the way to continue conservation as an evolutionary process in terms of its long‐term effects is not yet clarified. Measures of genetic variability not only within and across the species but also within and across phyletic lines are indicated for several ways of gene conservation and utilization of both intraspecific and interspecific variations of the various orders of gene pools. The patterns of variation of Ethiopian land race populations of Hordeum vulgare, Triticum turgidum and T. aestivum that were previously studied and reported are summarized. Hierarchical approaches to quantitatively define a center of genetic diversity into microcenters are suggested to be made among different species and among different pathogens, pests as well as parasites. The complexity of interacting genotypes in the composite populations of land races is discussed. The frequency and performance of the various genotypes of these land races varying across a given ecological gradient due to competition and/or coadaptation and being moulded by the specific effect of the environmental factors and multilocus genetic organization is presumed. The problems associated in selecting high yielding and other agronomically promising land races are pointed out. The regionally different multilocus structures and genotypic compositions, if taken with their respective possibly defined multilocus structure of parasites, pests and pathogens, will be of high interest in any selection schemes in each micro‐and megacenter of the regions studied. The problems of sampling for gene conservation works are presented. Some solutions are given. Three versions of sampling problems for gene conservation studies are discussed. Solutions for two versions based on sampling one genotype at a time, and several genotypes at a time, are presented.