Thesis
Evaluation of above- and below-ground traits exhibited by amphiploids for potential as a perennial grain in the Pacific Northwest
Washington State University
Master of Science (MS), Washington State University
2017
Handle:
https://hdl.handle.net/2376/100846
Abstract
Annual plants dominate current staple grain production. Developing grains with a perennial growth habit is an opportunity to produce staple grains in a more environmentally beneficial manner. Amphiploids of perennial tall wheatgrass (Thinopyrum elongatum) and common annual wheat (Triticum aestivum) have been produced and selected for wheat-like traits while exhibiting post-sexual cycle regrowth. Here, a germplasm study at two locations in the Palouse region of the U. S. Pacific Northwest evaluated 18 lines of amphiploids for agronomic and grain quality traits over an 18-month period; these amphiploids were compared to two released annual wheat varieties and an intermediate wheatgrass (Thinopyrum intermedium) selected for grain and agronomic traits. The yield was variable among the amphiploids, ranging from a mean yield per hectare equivalent of 713-2874 kg/ha compared to 1627-6867 kg/ha means in the winter wheat varieties. Winter survival after harvest was low and inconsistent at both locations. Two of the amphiploids were used in a residue management study investigating the effect of burning and mowing on second winter survival. Mowing the residue and post-sexual cycle regrowth of the plants following harvest significantly increased winter survival at one location from 3% in the untouched control to 63% in the mowed treatment. An amphiploid was used to compare root traits to annual wheat ('Madsen') and a perennial tall wheatgrass ('Alkar'). Mini-rhizotrons were used to follow the spatio-temporal aspects of root development, such as root length, new growth, and root diameter, to a depth of 160 cm from November 2015 to May 2017. Madsen was found to grow earlier, followed by SPS18A. Alkar was the last to develop its root system, reaching 160 cm an estimated 33 days after Madsen. When the autumn rains came, Alkar roots grew almost exclusively in the top 20 cm of the soil profile. SPS18A had root growth at the surface but growth was similar to depths interspersed throughout the observable profile. A similar trend was also seen in the following spring. This research demonstrates both the promise for the future of perennial grains and the challenges that remain before perennial grains can become a viable option for producers.
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Details
- Title
- Evaluation of above- and below-ground traits exhibited by amphiploids for potential as a perennial grain in the Pacific Northwest
- Creators
- Ian Clark
- Contributors
- Kevin Murphy (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Crop and Soil Sciences, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525099601842
- Language
- English
- Resource Type
- Thesis