VARIATION IN PROTEIN, SIZE AND SEEDLING VIGOR WITH POSITION OF SEED IN HEADS OF WINTER WHEAT CULTIVARS

Abstract

The protein content and size of winter wheat seed (Triticum aestivum L.) varies with the position of the seed in the head. Within a genotype, seed higher in protein content and/or larger in size will produce more vigorous seedlings. Regardless of cultivar, the seed from the a and b florets of the bottom 10 spikelets contained more protein per seed than that from all c florets and the a and b florets from above the 10th spikelet. In all cases, seedling vigor was significantly correlated with seed size and protein concentration, but was most closely correlated with protein per seed. A foliar application of urea after anthesis appreciably increased the quantity of protein per seed in all positions in the head of all cultivars. The increase was greatest in the a and b florets of the bottom 10 spikelets, not in those florets lowest in protein initially.