Responses of seeds of three species ofPseudopanaxtolow temperature stratification, removal of fruit flesh, and application of gibberellic acid

Abstract

Abstract Seeds of Pseudopanax ferox Kirk, P. crassifolius (A. Cunn.) C. Koch, and P. arboreus (Murr.) Philipson germinated more rapidly after 12 weeks of low temperature stratification, although their final germination percentage was unaffected. The presence of the fruit, either intact or as broken pieces, both delayed germination and reduced percentage germination of seeds of P. crassifolius. Germination was significantly delayed in the intact fruit of P. ferox, and germination percentages were reduced, but not significantly. Germination was neither significantly delayed nor reduced by the intact fruit or broken fruit of P. arboreus. Germination was depressed by acid scarification and unaffected by the application of 10-4 M gibbereilic acid, although scarified seeds of P. ferox and P. arboreus which were treated with gibbereilic acid germinated more rapidly than untreated scarified seeds. The inhibition of germination by the fruit and its flesh is interpreted as a mechanism for delaying germination in the field, although birds, such as the native pigeon, which are known to eat the fruits could potentially remove this source of inhibition and enhance germination.