Yield of wheat seed is a function of the number of grains produced per unit area and grain weight. Grain weight is affected by the rate and duration of the kernel growth. The objective of this experiment was to measure the rate and duration of grain filling of seven brazilian wheat genotypes in order to evaluate genotypic variation for these characters and to examine the relationship between rate and duration of grain filling, and other agronomic parameters. Significant genotypic variation for rate and duration of seed filling was observed. Rate of seed filling varied from 0.077 to 0.089 mg/seed/accumulated growing degree days, while duration of grain filling varied between 27 to 31 days. Rate, but not duration of grain filling, was correlated with grain weight. Kernel weight may be an appropriate selection criteria to be used by breeders to select early maturing wheat genotypes for higer grain filling rate.
Triticum aestivum; rate of grain filling; kernel weight