Bioassay of germination inhibitors in extracts of Sapium sebiferum seeds of different provenance

Sapium sebiferum seeds from Huangshan, Wuhan, and Guiyang in China were studied to identify differences in their 1,000-seed mass and in concentrations of inhibitors of germination in the seed coat or endosperm extracted using methanol or acetone. Seed mass varied significantly in relation to origin, with the highest mass observed in seeds from Wuhan, followed by seeds from Huangshan and Guiyang. Extracts of seed coats or endosperm caused a marked inhibition of the germination index of cabbage seeds, but less inhibition of germination percentages. Endosperm extracts had a stronger inhibitory effect on cabbage seed germination than seed coat extracts. Inhibitor concentrations in whole seeds also varied with seed origin. Seeds from Wuhan exhibited a significantly higher level of inhibition than those from Guiyang or Huangshan, but no significant differences were observed between seeds from Guiyang and Huangshan. The efficacy of methanol or acetone extraction was also evaluated. For whole seeds from Huangshan and Guiyang, methanol was more effective than acetone, while acetone performed better than methanol for seeds from Wuhan.