Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 12/15/1998
Publication Date: N/A
Interpretive Summary: It is often difficult to identify unique sources of genes in large plant germplasm collections. Also, it is important that germplasm collectors maximize their efforts when conducting field expeditions to find unique plants to add to existing germplasm collections. Several methodological approaches are provided to explore the relationship between features of the natural environments from where germplasm is collected and how closely different germplasm is related. It was possible to identify the geographic and climatic features of collecting environments that determine where different kinds of plants are naturally found. This kind of information will help germplasm users and managers more effectively plan future collection expeditions, reduce the changes of genetic diversity being lost and ensure that these valuable traits preserved for crop improvement.
Technical Abstract: The relationships of plants to their natural environments can be used to facilitate germplasm collection, maintenance, and utilization. The purpose of this paper is to: (i) provide a background on how germplasm genetic composition is influenced by natural environments; (ii) present methods using temperate forage legume examples. Ecogeographic data was estimated from latitude and longitude coordinates of collecting sites using geographic information system (GIS) software in conjunction with ecogeographic datasets. Nuclear ribosomal DNA internal transcribed spacer (ITS) sequences and random amplified polymorphic DNA (RAPD) markers were used to estimate inter-and intra-specific genetic relationships among forage germplasm collected at various levels of geographic scale and from diverse environments. Genetic associations with geographic characteristics of germplasm collection sites was done by the Mantel Z matrix comparison. Significant ecogeographic features related to genetic diversity were identified for different species, growth forms, regions, and levels of geographic scale. These approaches will help plan future collection expeditions by increasing the opportunities to find novel germplasm that is unique. Also, by integrating what we already know about germplasm holdings with information obtained from molecular and GIS technologies, genebank users will be better to manage, utilize, and preserve these valuable resources.