IMPROVING SELECTION FOR HEAT TOLERANCE IN BENTGRASS
Floral and Nursery Plants Research Unit
2012 Annual Report
1a.Objectives (from AD-416):
To identify bentgrass genome regions involved in heat tolerance.
1b.Approach (from AD-416):
Two experimental bentgrass populations have been developed at Rutgers University and both will be utilized to identify genomic regions influencing heat tolerance. One population was developed by one cooperator at Rutgers and is designated L-93-10 x 7418-3 this cross is a creeping by creeping cross consisting of 180 pseudo F2 progeny with an additional 450 F3 and backcross progeny are available. A genetic linkage map developed from the 180 pseudo F2 progeny is currently being constructed utilizing SSR markers and AFLP markers generated by the Floral and Nursery Plants Research Unit in Beltsville. Another population developed by another cooperator at Rutgers University is a creeping x colonial hybrid x creeping bentgrass cross designated (Hybrid 15 x 9188) and contains over 500 progeny from which 96 are being used in map development. The linkage map of the (Hybrid 15 x 9188) population is almost complete and contains gene based polymorphisms and AFLP marker produced by the Floral and Nursery Plants Research Unit in Beltsville. Both populations have had preliminary evaluations conducted that indicate the populations are segregating for heat tolerance. Plants of both populations will be maintained under well-watered conditions. Heat stress will be induced by growing plants at a temperature of 35/30 degrees C (day/night) in a large walk-in growth chamber. Turf quality will be rated visually based on a scale of 1-9 (9=best) as an indicator of general turf performance. In addition, several commonly used parameters for phenotyping heat tolerance, including leaf chlorophyll content, leaf photochemical efficiency, and cell membrane stability will be analyzed. The plant phenotyping work will be conducted in another Lab at Rutgers University.
This is the final report for this project. The research has used phenotypic data and linkage maps to identify several putative Quantitative Trait Loci (QTLs) for heat and drought tolerance in Agrostis. Additional research will be required to determine if these QTLs have relevance in other Agrostis germplasm.