ETHYLENE AS PROMOTER OF WHEAT-GRAIN MATURATION AND EAR SENESCENCE

This work was aimed at testing the involvement of ethylene in the matu ration of grain and senescence of the foliar structures of the wheat i nflorescence. Whole wheat ears emitted ethylene to the atmosphere. Fro m pre-anthesis, ethylene emission progressively increased from 0.76 nl g(-1)FW h(-1) to a peak 1.53 nl g(-1)FW h(-1) at the hard dough stage of the grains, to fall to a minimum of 0.10 nl g(-1)FW h(-1) at the d ormant seed stage. Ethephon increased the ethylene release, hastened t he process of grain maturation and senescence of the ears. Aminoethoxy vinylglycine and silver thiosulfate produced the opposite effects. It is concluded that ethylene plays a role in grain maturation and in the senescence of the green bracts of the inflorescence.