Stability analysis of stem solidness, grain yield and grain protein concentration in spring wheat

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), is a major pest of wheat (Triticum aestivum L.) in the northern Great Plains where it is a constant threat in Montana and is resurging in Alberta, Saskatchewan and North Dakota. Adoption of solid-stemmed cultivars is an important management tool for wheat growers; however, the inconsistent pith expression first noted with the release of ‘Rescue’ has been repeatedly observed in modern cultivars such as ‘Lillian’ in Canada. Given the extensive hectares planted to solid-stemmed wheat cultivars during an outbreak, identification of cultivars that display stable stem solidness, grain yield and grain protein concentration across a wide range of environments where stem sawfly infestations occur is desirable. We assessed spring wheat plant responses in eight solid-stemmed and two hollow-stemmed genotypes grown across diverse environments using multiple statistical models. Study sites included southern Alberta and Saskatchewan, Montana and North Dakota. Most models agreed that the genotypes, ‘Choteau’ ‘BW925’ and ‘Mott’ consistently displayed high and stable stem solidness concomitant with high grain yield. ‘Choteau’ and ‘BW925’ also consistently met or exceeded the desired threshold of a 3.75/5 pith rating (averaged from the lower four stem internodes) for optimum resistance whereas, ‘Mott’ developed optimal pith at a specific (early) phenological stage when resistance to WSS infestation is critical. Exploring stability of stem solidness identified ideal genotypes that would enhance germplasm development efforts, which exemplifies how this approach can facilitate the selection, production, and adoption of solid-stemmed wheat cultivars in regions prone to WSS attack.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author