ETHYLENE AS PROMOTER OF WHEAT-GRAIN MATURATION AND EAR SENESCENCE

This work was aimed at testing the involvement of ethylene in the maturation of grain and senescence of the foliar structures of the wheat inflorescence. Whole wheat ears emitted ethylene to the atmosphere. From 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 dormant seed stage. Ethephon increased the ethylene release, hastened the process of grain maturation and senescence of the ears. Aminoethoxyvinylglycine 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.