Effects of light on the germination of Petunia hybrida seeds

Abstract

In this study, the germination responses of Petunia hybrida seeds to light were investigated, and the following results were obtained.
1) The increase of germinative capacity of petu-nia seeds during the dry storage at room tem-perature was accompanied by the increased light-sensitivity. High sensitivity was gained 6 months after the harvesting.
2) The light-sensitivity of petunia seeds increased with the lengthening of presoaking, up to 48 hours, before the illumination. Moreover, as short as 5 minutes' illumination brought high germination, when it was given 20 hours after the imbibition.
3) Red light was more effective than green or blue light in increasing the germination percentage.
4) Petunia seeds were similar to lettuce seeds in the photoreversibility of their response to red and infra-red radiation.
5) The promoting effect of gibberellin was very remarkable, though nitrates and thiourea could not increase the germination.