|Changes in Evaluations|
Starting with harvest year 2010, we have made the following changes in the evaluations. Our goal is to provide more consistent and complete information on milling and baking performance of new wheat lines and cultivars. Through a generous grant funded by the state of Ohio, the Soft Wheat Quality Laboratory has access to a new diode array NIR instrument that measures whole grain spectra. As a result we will now provide whole grain protein and grain hardness with the quality information. We also are using this instrument to develop prediction models for milling yield and softness equivalent (break flour yield). Analysis of the first two years of data, in collaboration with Mary Guttieri and Clay Sneller of Ohio State University, is promising. Prediction equations for milling yield and softness equivalent using the NIR instrument have R2 values of over 75%. Our intent is to launch the use of NIR analysis for non-destructive milling yield selection within the next 18 months.
We are using multiple checks for adjusting the quality scores in the group. Previously, a single check was used for the scoring. This caused problems for a number of the evaluations due to 1) genotype x environment interactions and 2) interactions between cultivars for cookie diameters using the old sugar-snap cookie method and the revised AACC sugar-snap cookie method. Using the average of multiple checks should make the adjustments more robust. We transitioned to a new database of check cultivar performance that uses advanced milling data and cookie bakes using the revised AACC sugar-snap cookie method. The scoring system is still indirectly based on Allis mill ratings of cultivars. We also are flagging individual quality evaluations with ‘+’ for desirable quality and ‘q’ as undesirable quality. In reality these designations are based off of values greater or less than the average of the checks by more than a standard error. Lactic acid SRC is the exception to this culling. Lines are marked with an ‘s’ for stronger than average or ‘w’ for weaker than average for gluten strength.
The scores given in above table under the heading ‘advanced milling database scoring’ derive from the average milling and baking scores given in 5 or more millings from trials with sound grain. We transitioned to the advanced milling so that we could have more of the data based the revised AACC sugar snap cookie data and have a broader range of check cultivars from which to choose. The advanced milling database used for this adjustment will be posted on the SWQL web-site during September.
Lactic acid SRC values of gluten strength will be reported on an ‘as is’ basis. We have previously corrected the lactic acid SRC values to a 9% flour protein value using the formula of 7% point increase for every 1% point increase in flour protein. After looking at many trials across many regions, we felt that this adjustment was creating more problems than it was solving. In recent years we have had many low protein trials that have resulted in very large adjustments of lactic acid that are not realistic expectations of the genetic potential of the cultivars. We also see that some genotypes can be much more responsive than model due to the presence of 5+10 allele at the GluD1 locus with the absence of the rye translocation on the short arm of the chromosome 1B. We can provide the lactic acid values on a protein corrected basis if requested by a researcher.
Please give us feedback on the changes in the evaluations. We are open to your suggestions for continuous improvement.