Kernel texture differences among US soft wheat cultivars

Kernel texture is a key factor in the quality and utilization of soft wheat ( Triticum aestivum L), yet the variation in kernel texture among US soft wheat cultivars is largely unknown. This study evaluated the following hypothesis: soft wheat cultivars differ in kernel texture due to minor genetic factor(s). Once identified, selected contrasting cultivars could serve as candidates for crop improvement and future genetic studies. To test the hypothesis, kernel texture (SKCS, Single Kernel Characterization System), NIR (near‐infrared reflectance) and Quadrumat break flour yield were evaluated for 30 cultivars drawn from the four major US soft wheat regions and sub‐classes (eastern and western soft white winter, soft red winter and Club). Cultivars were grown in replicated trials over 6 site‐years in Washington state. The results clearly indicated that relatively large, consistent genetic differences in kernel texture exist among US soft wheat cultivars. SKCS and NIR were fairly well correlated ( r = 0.85) and tended to rank cultivars in the same order. However, individual cultivars deviated from this linear relationship and occasionally rankings changed substantially. Trends were observed among the geographical regions and sub‐classes, eg the first 13 hardest‐ranked positions (SKCS) were held by western cultivars (13 of the 16 total western cultivars). Quadrumat break flour yield provided an independent assessment of kernel texture and was not correlated with SKCS or NIR hardness. Four distinct cultivar groupings were made based on analysis of variance and two‐dimensional graphical assessment. Each group represented contrasting levels of kernel texture (SKCS or NIR) and break flour yield. Identification of the specific underlying gene(s) conferring kernel texture variation among US soft wheats awaits the next phase of research. Copyright © 2005 Society of Chemical Industry