Seed Germination in Ginkgo biloba L. I. Influences of Cold Treatment, Gibberellic Acid and Red Light

The influences of cold treatment, gibberellic acid and red light treatment on rate of germination of seeds of Ginkgo biloba L. were followed for a 12-wk period. Dispersal units were collected, and the outer fleshy layer was removed soon after harvest. Of water-imbibed, non-cold-treated seeds, 50% of those which germinated did so within 11 wk after planting. A single application of red light accelerated the 50% germination time by 3 wk. Imbibition in GA3 solution did not appear to accelerate germination. With 4-wk cold treatment the 50% germination time was accelerated 6 wk in water-imbibed seeds. Both red light and GA3 treated seeds also were accelerated 6 wk by cold treatment. An 8-wk cold treatment accelerated the 50% germination time 7 wk for all three treatment groups. The influence of red light observed on non-cold-treated seeds was not seen with seeds receiving a cold treatment prior to irradiation. A 12-wk cold treatment period delayed germination in all treated groups. Dry storage of seeds for 4mo at 25 C also delayed germination regardless of red light, GA3 or cold treatment

Fluorgraphic Technique for Detecting and Recording Chlorophyll and its Derivatives on Paper and Thin-Layer Chromatograms

Light from a blacklight lamp (General Electric BLB) is restricted to a waveband range 360 - 470 nm by cut-off filters consisting of 4cm 1 M aqueous CuSO4 and acrylic plastic sheets. This filtered lamp emission is used to excite the characteristic red fluorescence of chlorophyll and its derivatives on paper or thin-layer chromatograms. Fluorescent spots are detected and recorded by exposure of red-sensitive panchromatic photographic printing paper (Kodak Panalure) to the fluorescing chromatogram. A thin yellow filter interposed between the chromatogram and the photo print paper restricts the detected fluorescence to wavelengths greater than about 500 nm. Standard development of the photoprint yields grey to black spots on a white background. Intensity and size of the recorded spot is proportional to the amount of a single chlorophyll derivative on the chromatogram over a limited range of pigment applied to the chromatogram. A one-minute exposure with filtered light from an 8 watt GE BLB lamp at a 10-cm distance will record 0.3 nanomole (270 nanogram) chlorophyll a on Whatman No. 1 or on Whatman 3 MM paper chromatograms. Detection of chlorophyll derivatives by this technique is at least 10-fold more sensitive than visualization of the pigment spots on the chromatograms by their green color. This fluorographic technique can be a useful adjunct to chromatographic analyses of porphyrins in general