ARS | Publication request: MOLECULAR SYSTEMATICS AND EVOLUTION OF CROP PLANTS

Submitted to: Enfoques Contemporaneos Para El Estudio De La Biodiversidad
Publication Type: Book / Chapter
Publication Acceptance Date: May 28, 1999
Publication Date: N/A

Interpretive Summary: It is very important to have a good understanding of the relationships and genetic structure of crops and their wild species relatives for many reasons. In recent years, the study of relationships and genetics has become much more precise due to refined techniques using a plant's genetic material called DNA. This paper reviews DNA studies of crop plants since 1994. It shows how these studies have addressed many fundamental and practical questions ranging from determining differences between species, showing the relationships between species, investigating patterns of diversity in different geographic areas and in different habitats, investigating whether a species is the product of natural hybridization, showing how useful different types of DNA are by showing agreement of different DNA results, using DNA to determine how to best operate genebanks (places where crops are maintained for breeders), and a variety of other studies. This paper is designed as an introduction to the subject by beginning students of crop evolution who will benefit by having a comprehensive overview of modern methods to study crop evolution.

Technical Abstract: Crop plants possess a variety of traits that typically distinguish them from wild species. They evolve also under artificial selection and often possess novel or extreme traits relative to their progenitor(s). Crops often are very closely related to their wild relatives, although not all are known. Multiple origins of some cultivars and frequent hybridization with their wild relatives produces complex patterns of diversity that makes the taxonomy of many crops difficult. Molecular markers are useful to help unravel the complex evolutionary history and determine patterns of diversity of crops. This paper surveys molecular marker studies relating to systematics and evolution of crop plants from 1994 to the present. Molecular markers have been used to address many questions ranging from determining species and species interrelationships, biogeography, confirming natural and artificial hybridization and introgression, the evolution of nodulation, concordance of different data sets, determining accession-specific and species-specific diagnostic markers, distinguishing auto- from allopolyploid inheritance, testing the effects of molecular marker diversity on heterosis, the design and maintenance of genebanks, the evolution of domestication, and genome evolution.