|GARCIA D L SANTOS, G|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2000
Publication Date: 4/30/2001
Interpretive Summary: Birdsfoot trefoil is an important forage legume for livestock production and has other uses as a conservation species where habitats have been disturbed. The USDA National Plant Germplasm System collections contain a wide array of genes of this and other species that can be used to developed improved varieties. To make these genes more easily available and useful to forage breeders and conservationist interested in restoring habitats, methods are needed to identify the plant germplasm that may be best adapted for use in different regions of the world. This research showed that the genetic background of birdsfoot trefoil collected in Asia and Europe was related to the environmental features of the collecting sites, and that the morphology of these plants were associated with different ecogeographic features. By understanding the relationship between genetic diversity and where germplasm will best grow, the valuable natural resources found in germplasm collections can be preserved and effectively utilized.
Technical Abstract: Birdsfoot trefoil (Lotus corniculatus L.) is a highly variable and widely distributed perennial forage legume found throughout temperate regions of Europe, Asia Minor, North Africa, and North and South America, Australia, and New Zealand. Understanding the relationships among birdsfoot trefoil morphologic, ecogeographic, and genetic characteristics may provide insights for better utilizing exotic germplasm. The objectives of this research were to compare morphologic and random amplified polymorphic DNA (RAPD) classifications of 28 exotic and ecologically diverse genotypes from the USDA National Plant Germplasm System birdsfoot trefoil collection, and determine the relationships between genotype classifications and collecting site ecogeographic features. Eighteen morphologic characteristics, 130 RAPD bands, and eight ecogeographic characteristics were used to classify the genotypes. The relatedness of genetic, morphologic, ecologic, and geographic distances was measured using Mantel's Z test. Genotype morphologic similarities were related to collecting site distances and ecologic similarity. Genetic similarities were also related to collection site ecology, and specific morphologic characteristics were associated with different ecogeographic features. The similarity between the genetic and ecologic classifications suggests that genotypes adapted to similar habitats, even if geographically distant, have acquired similar phenotypes. Because RAPD descriptors were associated with the ecologic similarity of genotype collection sites but not with their geographic closeness, classifications of germplasm should not rely solely on germplasm geographic or morphologic characteristics.