Factors affecting dry weight accumulation in developing barley endosperm

Abstract

Some factors that may be concerned in determining final grain weight in barley (Hordeum vulgare L. var. distichum) have been investigated. Variation in endosperm fresh and dry weight, volume and starch content have been recorded at different stages of grain development between anthesis and harvest‐ripeness for two barleys, cvs Kym and Golden Promise, differing in final grain weight. Results were recorded under both field and glasshouse conditions. The results suggest that the higher final dry weight of Kym, in comparison with Golden Promise, is a function of both rate and duration of grain filling. Only at later stages of endosperm development did the differences in volume become significant and the Kym endosperms continued to increased rapidly in volume for two to three days after endosperm volume had reached a maximum in Golden Promise. The rates of starch accumulation in both cultivars were very similar but starch deposition continued in Kym endosperms for four to five days after deposition in Golden Promise endosperms had slowed down.