Genotypic and Phenotypic Characterization of Soft Red Winter Wheat: Improved Cultivar Placement during Periods of Climate Change.

Title: Genotypic and phenotypic characterization of VRN and PPD alleles in soft red winter wheat

 Authors: Ethan Snyder, Carrie Knott, David Van Sanford, and Montserrat Salmeron

 Abstract: Selection of soft red winter wheat (Triticum aestivum L.) cultivars best adapted to different climatic conditions is critical for reducing risk of spring freeze and allowing an early harvest suitable for double cropping in Kentucky.  Moreover, cultivar selection offers producers a potential adaptation strategy to mitigate climate change effects.  The objectives of this study are to 1) genotype and phenotype 50 wheat lines with different vernalization (VRN) and photoperiod (PPD) alleles, and 2) determine the photoperiod response and thermal time required by each wheat line to reach key developmental growth stages in Kentucky. 

                A field experiment was conducted in Princeton, Kentucky with monthly plantings from October to March for three growing seasons beginning in fall 2013.  Traits measured include number of spikelets per spike (2014); date of full flowering (Feekes 10.5.3), (2015); date of emergence (Feekes 1), tillering (Feekes 3), pseudostem erection (Feekes 5), jointing (Feekes 6), heading (Feekes 10.5), full flowering, and harvest maturity (Feekes 11.4), (2016).  Seed number and total grain weight were measured in all harvest years.   

                In addition, the 50 soft red winter wheat lines were planted in a greenhouse on December 10, 2015. At Feekes 2 stage (approximately 8 days), the seedlings were moved to the field for 3, 6, or 9 weeks. After this time, the seedlings were moved back into the greenhouse where developmental changes were recorded until full flowering. The thermal time and photoperiod response to key developmental stages will be studied for the 50 lines across environments and treatments. The lines will also be genotyped at VRN and PPD loci using KASP markers.

                Results from this study have wide applications to develop predictive models and decision tools for winter wheat management. Ultimately, these decision tools can assist Kentucky winter wheat producers in making informed decisions and modifying their production system to increase grain yield.