Seed germination of panicum maximum Jacq. in relation to respiratory inhibitors and gibberellic acid treatments

The germination of guinea grass seeds (Panicum maximum Jacq.) was studied in relation to potassium cyanide (KCN), salicylhydroxamic acid (SHAM) and gibberellic acid (GA₃). The application of KCN (a cytochrome oxidase inhibitor) at 1 and 2mM concentration resulted in a slight stimulation of germination while the application of 10 mM SHAM (an alternative respiration inhibitor) caused a reduction. However, SHAM markedly stimulated germination when applied as a pulse treatment during the first 24 h of imbibition. KCN was ineffective. In combination KCN and SHAM were inhibitory in both the cases. Seemingly, a diminution of alternative respiration during early imbibition was stimulatory for germination. A marked stimulation of germination by GA₃ was negated by applications of either SHAM or KCN.