UTDG-101, a late-maturing orchardgrass germplasm with increased winter hardiness and forage quality.

摘要

The USDA-ARS announces the public release of the orchardgrass ( Dactylis glomerata L.) UTDG-101 germplasm (Reg. No. GP-5, PI 672006) as a late-maturing grass with excellent forage quality and increased winter tolerance for use in orchardgrass breeding programs. Selection emphasis in UTDG-101 was for late maturity, winter hardiness, and dry matter yield. UTDG-101 traces back to polycross seed that originated from crosses among four orchardgrass collections (PI 659612, PI 659613, W6 20243, and W6 20247) made within 100 km west-southwest of Zhaosu County, Xinjiang Uyghur Autonomous Region, China. UTDG-101 is more genetically distinct than orchardgrass cultivars Paiute, Pennlate, and Benchmark. UTDG-101 has significantly ( P<0.05) longer flag leaves than the orchardgrass cultivars examined in this study. Based on mitotic root counts, UTDG-101 is an autotetraploid (2 n=4 x=28). In forage harvested May 2011, UTDG-101 had significantly higher crude protein, relative feed value, sugars, water-soluble carbohydrates (WSC; sugars+fructans), and digestibility and significantly lower acid detergent fiber and neutral detergent fiber (NDF). Forage of UTDG-101 harvested July 2011 had significantly lower NDF and increased fructan, sugar, and WSC concentrations. UTDG-101 exhibited significantly less winter injury than other orchardgrass, tall fescue [ Schedonorus arundinaceus (Schreb.) Dumort.], and perennial ryegrass ( Lolium perenne L.) cultivars. Due to the high combining ability, late maturity, increased forage quality, and winter hardiness of UTDG-101, this source of germplasm could provide genetic resources for developing late-maturing orchardgrass with increased forage quality and reduced winter injury for management with alfalfa ( Medicago sativa L.) mixtures or for grazing.