EFFECT OF PROTEIN CONTENT ON SEED PERFORMANCE IN WHEAT (TRITICUM AESTIVUM L.)

The objectives of this study were to determine the effects of nitrogen fertilization on chemical and morphological characteristics of wheat (Triticum aestivum L.) seed and the effect of protein level on seed and seedling performance. Seed of different protein contents were obtained by fall and spring applications of various rates of nitrogen to "Nugaines" soft white winter wheat. The increase in protein content from high nitrogen rates was accompanied by a decrease in seed size. The protein increase occurred primarily in the endosperm. Neither protein content of the embryo nor embryo size was affected by the rate of nitrogen application. The rates of water absorption and oxygen consumption of germinating seed increased as a result of the high protein content. The higher protein seed had a faster speed of germination and developed into larger seedlings with a higher dry matter content when grown in nitrogen-deficient soil. Seed with high protein content performed better under stress conditions and especially so when plant growth depended on the nutrients available from the seed. During this period, especially during initiation of germination, temperature influenced the expression of the protein effect. After the seedling was formed, the effect of seed protein content on plant growth was influenced by the amount of soil nitrogen available to the plant.