|Johnston, W. - WASHINGTON STATE UNIV.|
Submitted to: Diversity Magazine
Publication Type: Popular Publication
Publication Acceptance Date: September 1, 2000
Publication Date: N/A
Interpretive Summary: Kentucky bluegrass is used extensively for golf courses, parks, athletic fields, lawns, and grazing pastures. It is the most widely used cool-season turfgrass in North America. Kentucky bluegrass is hardy, persistent, and best adapted to sunny sites in temperate to subarctic climates around the world. There is tremendous diversity within Kentucky bluegrass owing to a long period of natural selection over a wide geographic range with extensive climatic variation. The USDA-ARS maintains a collection of Kentucky bluegrass represented by more than 300 accessions from 27 countries, which is available to researchers at no charge. In a cooperative program between Washington State University and the USDA-ARS, Pullman WA, this collection was extensively evaluated for basic agronomic traits. This information was used to develop a core subset of accessions that represented most of diversity found in the larger collection. This core was used in advanced evaluation work for factors such as yield and turf quality that would have been too expensive to complete on the entire collection. Through this effort, a number of accessions were found that have potential for utilization in breeding programs to develop improved Kentucky bluegrass.
Technical Abstract: The USDA-ARS maintains a germplasm collection of Kentucky bluegrass (Poa pratensis L.) with more than 300 accessions from 27 countries. Utilization of these genetic resources to develop improved cultivars are significantly enhanced by evaluation information. An extensive evaluation program has been completed on this collection in a cooperative program between Washington State University and the USDA-ARS, Pullman, WA. Using 17 agronomic crop descriptors, all available accessions in the collection were evaluated. A cluster analysis was completed on the descriptor data that allowed accessions to be grouped together based on the their similarity. From this information a subset of 20 accessions, or a core collection, was developed. The core collection has been evaluated for factors such as seed yield and turf quality that would be impractical to complete on the entire collection. These studies have shown that seed yield is negatively correlated with date of seed harvest and that higher turf quality was consistently related to later heading, but yield and turf quality were not correlated. Although the combination of high yield and turf quality was rare it is possible to find accessions with both attributes. In general, the USDA Kentucky bluegrass collection is under represented in many key geographic areas of Poa diversity worldwide, indicating a need for continued collection and evaluation of new germplasm.