Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2007
Publication Date: 11/4/2007
Citation: Casler, M.D., Johnson, R.C., Barker, R.E., Jenderek, M.M., Papadopolous, Y.A., Cheney, J.H. 2007. Seed Production from Non-flowering Orchardgrass: Proof of Concept. ASA-CSSA-SSSA Annual Meeting Abstracts. Paper Number 175-1. Interpretive Summary: Non-flowering or sparse flowering orchardgrass would greatly simplify management of intensive rotational grazing systems in which flowering stems are an impediment to efficient pasture utilization. We verified that orchardgrass plants that do not flower in cold-weather forage production environments may still be capable of flowering and producing seed in warm-weather seed production environments. We also discovered that the best non-flowering plants (for seed production in Oregon and Washington) originated from the coldest of the original selection locations. These results will be useful to orchardgrass breeders in the development of new sparse-flowering varieties.
Technical Abstract: Non-flowering or sparse flowering orchardgrass (Dactylis glomerata L.) would greatly simplify management of intensive rotational grazing systems in which flowering stems are an impediment to efficient pasture utilization. Our objective was to quantify seed production on non-flowering orchardgrass clones selected in cold-winter climates, but grown for seed in mild-winter climates. We evaluated 98 orchardgrass clones for seed production traits at four locations: Pullman and Central Ferry, WA; Corvallis, OR; and Parlier, CA. Most plants (~92%) flowered at the three northern locations, but only 38% flowered at Parlier. The latter location may have a winter that is insufficiently cold for adequate floral induction and vernalization. Among non-flowering plants that flowered at the three northern locations, number of panicles and plant seed yield were reduced by 64% relative to that of two check cultivars. Mean panicle number was lowest (11%) for plants selected at Ithaca, NY, the selection location with the warmest winter conditions, and highest (37%) for plants selected at Charlottetown, PEI, the selection location with the coldest winter conditions. Because flowering in these plants appears to be regulated by winter temperatures, these results confirm our expectations that the most desirable plants (non-flowering under cold winters and normal flowering under mild winters) should arise from selection under more severe winter conditions. Intensive selection among the 86 clones originating from non-flowering germplasm identified five clones with high and stable seed production at all three northern locations, averaging only 12% fewer panicles, but 54% higher panicle seed yield and 24% higher plant seed yield compared to check cultivars. These results provide proof-of-concept that orchardgrass plants selected for stable expression of the non-flowering trait are capable of producing adequate seed yields in typical orchardgrass seed production environments, provided some relatively intensive selection pressure for seed production traits.