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United States Department of Agriculture

Agricultural Research Service

Title: Stability of Non-Flowering Orchardgrass

Authors
item Casler, Michael
item Barker, Reed
item Papadopolous, Y - AAFC CHARLOTTETOWN PEI
item Cherney, J - CORNELL UNIVERSITY

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 12, 2004
Publication Date: March 12, 2004
Citation: Casler, M.D., Barker, R.E., Papadopolous, Y., Cherney, J.H. 2004. Stability of non-flowering orchardgrass. Crop Science. 44:1601-1607.

Interpretive Summary: Orchardgrass (Dactylis glomerata L.) is a valuable pasture species in much of temperate humid North America. However, profuse and early flowering in spring creates management problems for graziers and reduces intake of livestock in a management-intensive rotational grazing system. Casler et al. demonstrated that non-flowering orchardgrass populations have plants with a wide range of expression of this trait, ranging from slightly sensitive (sparse-flowering in one year) to highly sensitive (stable non-flowering across years). The non-flowering trait appears to be controlled by genes that are temperature sensitive, with lower winter (short-day) temperatures increasing expression of the trait. Non-flowering populations had adequate panicle production in a seed production environment, suggestion that commercial seed production of non flowering orchardgrass is possible. The results of this study suggest potential for commercial development of the non flowering trait in orchardgrass and there are probably a sufficient number of forage-based grazing operations in temperate North America to create a commercial market for this germplasm.

Technical Abstract: Orchardgrass (Dactylis glomerata L.) is a valuable pasture species in much of temperate humid North America. However, profuse and early flowering in spring creates management problems for graziers and reduces intake of livestock in a management-intensive rotational grazing system. The objectives of this study were estimate environmental stability, genotypic variability, and frequency of non-flowering and sparse-flowering plants in two sparse-flowering orchardgrass populations. Seven cultivars and 299 half-sib families were evaluated for 2 years at five locations between 42º and 47ºN latitude. Populations WO-SF-B and WO-SF-C were later in maturity, produced fewer panicles per plant, and had higher frequencies of sparse-flowering and non-flowering plants than the cultivars. Plants had varying levels of expression of the non-flowering trait, ranging from slightly sensitive (sparse-flowering in one year) to highly sensitive (stable non-flowering across years), with highly sensitive plants found only within populations WO-SF-B and WO-SF-C. The non-flowering trait of orchardgrass appears to be controlled by floral-regulation genes that are turned off by short-day temperatures below a critical threshold. Such a threshold appears to exist for all orchardgrass plants, but is increased in those plants expressing the non-flowering trait.

Last Modified: 8/22/2014
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