Wednesday, November 15, 2006

Pollen Dispersal and Hybridization Potential in Tall fescue and Italian ryegrass.

Kunjun Han1, Andrew Hopkins2, German Spangenberg3, and Zeng-Yu Wang2. (1) Samuel Noble Foundation, PO Box 2180, Ardmore, OK 73402-2180, (2) The Samuel Roberts Noble Foundation, Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, (3) Plant Biotechnology Center, Plant Biotechnology Center, Primary Industries Research Victoria, Department of Primary Industries, Bundoora, Victoria 3083, Australia, Boondra, 3083, Australia

Information regarding gene flow in wind-pollinated outcrossing forage and turf grasses is essential for regulation and the future release of transgenic cultivars. Field experiments have been conducted in 2005 and 2006 to address pollen dispersal of tall fescue and Italian ryegrass. Both experiments used transgenic tall fescue and transgenic Italian ryegrass carrying marker genes, as the sources of pollen. The test field was designed in a wheel spoke shape with a 0.25 acre donor plot in the center of the field.  A total of 360 transgenic tall fescue and 360 each of the two transgenic Italian ryegrass lines were planted in the central plot. Four each of wild-type tall fescue and Italian ryegrass were transplanted in an exclosure to capture the pollens from the center plot.  Exclosures are exactly 25 m apart from each other with the farthest reaching to 375 m. The exclosures run North, Northeast, East, Southeast, South, Southwest, West, and Northwest.  Farther pollen flow was observed in the North direction and pollen flow frequency showed leptokurtic or bimodal distributions.