Abstract

FERNANDEZ-PADILLA, Katheryne; VELEZ-DE LA ROCHA, Rosabel  and  VALENZUELA-SOTO, Elisa M.. Heat Stress in Different Development Stages of Wheat Modifies the Grain Chemical Composition and Germination Index. J. Mex. Chem. Soc [online]. 2023, vol.67, n.3, pp.275-283.  Epub Apr 22, 2024. ISSN 1870-249X.  https://doi.org/10.29356/jmcs.v67i3.2050.

Climate change is causing increases in temperature in wheat-producing areas of the world. The global warming conditions put wheat production at risk. In wheat, heat stress causes a decrease in the yield due to retarding grain fill time and maturity. This work aimed to evaluate the grain chemical composition of six wheat genotypes subjected to heat stress during the vegetative and reproductive stages and to relate it to germination. Grains of six wheat genotypes were used in this study, cultivated in the Yaqui Valley, Sonora, in December 2020 and January and October 2021. The flour was obtained from whole grains (40 gr of each genotype and each sowing date). Proximal analyses were done following AACC and AOAC methods. Starch content was determined using a commercial kit from Megazyme. Changes in size, shape, and colour were observed in all the seeds progeny of plants under heat stress during the vegetative and reproductive stages. Heat stress during the reproductive stage reduced the thousand-grain weight, total solids, and protein content in the progeny grains but increased the percentage of moisture, ash, total starch, and germination index. Heat stress during the vegetative stage reduced total solids content and increased thousand-grain weight, moisture, and total starch in the progeny grains. The germination index in seeds from plants subjected to heat stress during the reproductive stage was associated with total starch content and a trend to decrease total protein. That association was not found in seeds from plants under heat stress during the vegetative stage.

Keywords : Heat stress; germination; starch; thousand-grain weight; wheat.

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