Endosperm cell number in barley

Abstract

Grain weight is one of the major components of grain yield and it has been suggested that in wheat, final grain weight may be a function of endosperm cell number¹. If grain weight is to be increased by increasing the rate and/or duration of endosperm cell division, it is important to establish the stage of development at which maximum endosperm cell number is attained. Evers² reported that no cell division occurred in the endosperm of wheat later than 16 days after anthesis and other workers^3,4 have come to a similar conclusion using cell counts. However, biochemical analyses⁵ have shown that the maximum DNA content of wheat endosperm is not reached until 25 days after anthesis and both Donovan⁶ and Radley⁷ have suggested that endosperm cell division may continue until about 30 days after anthesis. We have estimated the number of endosperm nuclei in developing caryopses of barley and have examined transverse sections of endosperms of different ages. We report here that cell division in barley endosperm continues until 28–30 days after anthesis.