EFFECT OF SEED AGING ON CHLOROPHYLL(IDE) ACCUMULATION AND HILL ACTIVITY IN GREENING SOYBEAN SEEDLING COTYLEDONS

Cotyledons of soybean seedlings grown from artificially aged seeds sho wed an extended lag-phase and reduced biosynthetic potential for chlor ophyll(ide) accumulation in comparison to those from the unaged seeds. 5-aminolevulinic acid (ALA) treatment reversed the effect of ageing, though only partially. Hill activity of the chloroplasts of seedling c otyledons from aged seeds appeared to be conserved when calculated per unit Chl(ide) amount, but showed significant reduction on fresh mass basis. Thus the capacity for Chl(ide) accumulation should be considere d together with other criteria when the field performance of seeds is evaluated.