Response of Qualitative Characteristics of Spring Bread Wheat (Triticum aestivum L.) to Terminal Heat and Determine Correlation Between Traits

Terminal heat stress affected on qualitative characters. Identification of relation between heat tolerance and baking quality is more important. Many quality characteristics are important for the utilization of wheat, particularly flour protein concentration and bread-making properties.
This study was performed to evaluate the tolerance of bread wheat genotypes qualitative traits to extreme heat stress (above 40 C◦). Genotypes were evaluated in two separate experiments in 2 years.
The experiment was laid out in split- split- plot design with 3 replications at field of Safi Abad Dezful (Khuzestan province of Iran) Agricultural Research Station in 2014-2016. To study qualitative traits and seed protein, 4 genotypes (Chamran, Baj, Chamran2 and ER-92-19), 3 cultivation methods (stripe, 2 line on bed and 3 line on bed) and 3 seed rate (400, 600 and 800 seed.m-2) are selected.
Seven qualitative traits involve bread value (BV), hardening index (HI), Moisture%, Protein%, WA% (water absorbance), Zeleny and Wet gluten was measured. Correlation coefficient results seed protein% had negative with HI, BV and Zeleny. BV had positive correlation with HI and positive with flour moisture and wet gluten. Results showed that cultivation method influence on BV and seed protein. Only BV influenced by seed rate. In 600 seed.m-2 BV was the least (513.21) and in 800 seed.m-2 was the most (519.28). Genotypes in BV, HI, protein and Zeleny had significant differences. These results are so useful for preparing gluten free breads. But more research require.
In hot climate such as north of Khuzestan province of Iran that spring has above temperature and multiple cropping system is usual, cultivation of tolerant and early mature genotypes had economical. In Addition with good management, seed quality is better than forecasting. So researchers can promote this project and farmers can use these results surely.