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Abstract
Fungal and fire treatments were applied to seeds of Albizia julibrissin to simulate natural mechanisms of seed coat scarification. Seeds in unsterilized soil which contained natural microorganisms resulted in increased germination compared to seeds in sterilized media. Germination in cultures of Rhizoctonia, Fusarium, and Pythium indicated Rhizoctonia was most effective as a seed scarifier. Fire treatment at 1, 3, 5, and 10 seconds indicate that 1 second enhanced seed germination. Scanning electron micrographs of treated seed indicated that fungal hyphae alters the surface of the macrosclereid cells which may allow for imbibition of water. Seeds sub-jected to fire had large cracks in the macrosclereid layer.
Abstract
Four bromeliad species in the genus Neoregelia were studied by scanning electron microscopy (SEM) for morphological characteristics and density of trichomes that may influence absorptive capacities. Neoregelia trichomes were classically peltate, generally elliptic, exhibiting a web-like cap characteristic of the Bromelioideae. Minor variations were evident between species in morphology, density, and distribution. Copper from copper sulfate applied to leaf surfaces was absorbed and translocated as determined by atomic absorption spectrometry, but uptake was not related to trichome density as determined by SEM nondispersice technique.