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Title: SINGLE KERNEL PROTEIN VARIANCE STRUCTURE IN COMMERCIAL WHEAT FIELDS IN WESTERN KANSAS

Author
item BRAMBLE, TOD - KSU, MANHATTAN, KS
item HERRMAN, TIMOTHY - KSU, MANHATTAN, KS
item LOUGHIN, THOMAS - KSU, MANHATTAN, KS
item DOWELL, FLOYD

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2001
Publication Date: 10/20/2002
Citation: Single kernel variance structure in commercial wheat fields in Western Kansas. Crop Science. 2002. v. 42(5) p. 1488-1492.

Interpretive Summary: The protein variation should be understood in order to define the practical limits for managing and marketing wheat based on protein content. This research was undertaken to quantify the structure of protein variation in a commercial hard red winter wheat production system. Protein variability was studied with fields, in plots within fields, in rows within plots, in plants within rows, in heads on a single plant, in spikelet position on a single head, and in kernels within a spikelet. Kernels were evaluated for protein concentration using a single kernel characterization system equipped with a diode array near-infrared spectrometer (SKCS 4170). For the cultivars Jagger, 2137, and Ike, all sources of variability except for kernels within a spikelet were statistically significant. For TAM 107, variation attributed to fields and plants within fields were not significant. Field and plot sources of variability contributed the greatest amount of variance for Jagger, 2137, and Ike. For TAM 107, plots were the greatest source of variability. Jagger, Ike, and 2137 showed a significant protein gradient in which the highest protein concentration occurred at the base of the head and the lowest protein content at the top. For TAM 107, the greatest protein content was found at the base; however, the middle spikelet contained the lowest protein content followed by the top most spikelet. This information will augment our knowledge and practices of sampling, segregation, marketing, and varietal development to improve uniformity and end-use quality of wheat. This information will be useful to farmers, breeders, and FGIS.

Technical Abstract: This research was undertaken to quantify the structure of protein variation in a commercial hard red winter (HRW) wheat (Triticum aestivum L.) production system. This information will augment our knowledge and practices of sampling, segregating, marketing and varietal development to improve uniformity and end-use quality of HRW wheat. The allocation of kernel protein variance to specific components in southwestern Kansas was performed by a hierarchical sampling design. Sources of variability included Field, Plot (plots with a field), Row (rows within a plot), Plant (plants within a row). Head (heads within a plant), Position (spikelets at a specific position within a spikelet), Individual kernels (10 152) were collected from 46 fields planted to one of four cultivars: Jagger, 2137, Ike, or TAM 107. Kernels were evaluated for protein concentration by a single kernel characterization system equipped with a diode array near-infrared (NIR) spectrometer. For the cultivars 2137 and Ike, all sources of variability except Spikelet were statistically significant (P<0.05). For Jagger, all sources except Row were significant and for TAM 107, variation attribute4d to Field and Plant were not significant. Field and Plot sources of variability contributed the greatest amount of variance within the hierarchy for Jagger, 2137, and Ike. For TAM 107, Plot was the greatest source of variability. The least squares means were calculated for the fixed effect Position. Jagger, Ike, and 2137 showed a significant protein gradient in which the highest protein concentration occurred at the base of the hear and the lowest protein content at the top. For TAM 107, the greatest protein content was found at the base. Results of this study provide a benchmark for future efforts to improve wheat consistency through breeding and crop management. The protein variance structure described during this study also defines practical limits for managing and marketing protein content in HRW.