Effects of maternal light environment on germination and morphological characteristics of Sicyos deppei seeds

The effect was studied of sunlight and far-red (FR) light during seed devel opment. on seed quality and germination of Sicyos deppei G. Don. Seeds expo sed to FR during development were lighter in colour and their weight. size and water content were significantly lower. Less than 10% of non-scarified freshly harvested seeds germinated. Scarified, freshly harvested seeds deve loped under sunlight had a partially negative photoblastic response: both r ed (R) and FR light inhibited germination. The highest and fastest germinat ion occurred in darkness, probably due to the effect of the high photon flu x densities on the phytochrome during seed development. Scarified seeds rip ened under FR light, germinated well in FR light and in darkness, but R lig ht inhibited germination. After 6 months of storage, the permeability of S. deppei seeds increased, the partially negative photoblastic response was l ost and germination of scarified seeds increased. Specifically. in seeds de veloped under FR. germination in darkness was faster than for the other lig ht treatments, but slow in darkness for seeds developed under sunlight. The physiological and morphological heteroblastic responses in S. deppei proba bly extend its seed germination and seedling recruitment periods.