|GILL, K - Washington State University|
|KUMAR, NEERAJ - Washington State University|
|CARTER, A - Washington State University|
|RANDHAWA, H - Lethbridge Research Center|
|HIGGINBOTHAM, R - Washington State University|
|GUY, S - Washington State University|
|BURKE, I - Washington State University|
|LYON, D - Washington State University|
|MURRAY, T - Washington State University|
Submitted to: Journal of Plant Registrations
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2020
Publication Date: N/A
Interpretive Summary: Curiosity CL+ is a soft white common winter (PVP 201500290, PI 675007) wheat variety carrying two-genes for imidazolinone herbicide tolerance that was released in 2013 by the Agricultural Research Center (ARC) of the Washington State University (WSU). Most of the ‘Clearfield’ wheat varieties available in the PNW carry only single-gene imazamox tolerance and often show yield-reduction after spraying with standard imazamox rates, especially when spray overlaps occur in the fields. Because of this reason, wheat varieties carrying two genes for herbicide tolerance provide significantly better protection against yield loss from labeled use rates of herbicide application. The two-gene Clearfield varieties also allow using better surfactants such as methylated seed oil (MSO), instead of relatively milder surfactants like non-ionic surfactant (NIS). Curiosity CL+ has clearly better stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici Eriks.) resistance than Eltan. Snow mold is a devastating disease in winter wheat production in the colder regions of the USA, especially where snow falls on unfrozen or lightly frozen soil and persists for more than 100 days. Curiosity CL+ has a similar level of snow mold tolerance as Eltan. Curiosity CL+ is a high yielding semi-dwarf cultivar with intermediate plant height and is well adapted to the low rainfall (<300 mm of average annual precipitation), non-irrigated wheat production regions of Washington State. Curiosity CL+ was released as a two-gene Clearfield SWW wheat as an alternative to ORCF103 (PVP 200900464; PI 658153), ORCF102 (PVP 200500337), Eltan and Xerpha (PI 645605) cultivars that are widely grown in dryland areas in Washington State. Curiosity CL+ has soft grains and end-use quality assessment show good cookie diameter as well as superior sponge cake quality compared to the standard check variety ‘Stephens’ (CI 17596).
Technical Abstract: Curiosity CL+ is a soft white common winter wheat (Triticum aestivum L.) (PVP 201500290, PI 675007) carrying two-gene tolerance to imazamox herbicide, also known as a ‘Clearfield’ cultivar that was developed and released in 2013 by the Agricultural Research Center of the Washington State University (WSU). It is the first two-gene Clearfield wheat variety released by WSU. Curiosity CL+ was tested under the experimental designations EBC2F3-3-18 and WA008143. Curiosity CL+ was derived from two backcrosses between the soft white winter wheat cultivar ‘Eltan’ and CL0618 (an Australian hard red spring two-gene Clearfield mutant line) and selected using marker-assisted backcrossing. Two alleles (Als1 and Als2) with mutations in the acetolactate synthase (ALS) genes located on the long arms of 6B and 6D chromosomes, which provide tolerance to imazamox herbicide (trade name Beyond) were transferred to Eltan, a predominant cultivar in the Pacific Northwest region of the United States. Curiosity CL+ has better stripe rust resistance than Eltan and a similar level of snow mold and Cephalosporium stripe tolerance. Curiosity CL+ has high grain yield potential, intermediate semi-dwarf plant height and is well adapted to the dryland production areas with less than 300 mm of rainfall in Washington State. In herbicide resistance spray trials at multiple location-years, Curiosity CL+ showed equivalent herbicide tolerance compared to the two-gene Clearfield check cultivar ‘AP503CL2’ (PVP 200800322). Curiosity CL+ will provide additional options to control weeds using imazamox compared to single gene Clearfield varieties currently grown in Washington State. Curiosity CL+ has end-use quality characteristics similar to cultivars ‘ORCF102’, ‘Stephens’, and ‘Xerpha’.