The Effect of Seed Treatments on the Germination of Different Fabaceae Species of a Natural Meadow-Like Association

The goal of our experiment is to compose a species-rich seed mixture suitable for soil covering in orchard floor management in organic fruit production systems. Besides selection of traditionally used grass and Fabaceae species we are focusing on the involvement of local fora elements, of the experiment site, approaching a natural meadow-like association. Species of the following plant families are involved: Apiaceae, Asteraceae, Rosaceae, Linaceae, Polygonaceae, Dipsacaceae, Fabaceae, Poaceae. Seeds of selected species were tested to determine germination % before seeding, according to MSZ 6354-3:2008 standard in climate cabinet. Seed treatments (vernalisation, scarification) were carried out according to relevant standard. There were differences in the germination% of commercial and wild collected seed items of Agrimonia eupatoria L, Ajuga genevensis L, Lotus corniculatus L, and Achillea millefolium L. The applied seed treatments resulted significant difference between the treated and non-treated seed items most of the tested species related their germination%. For example in case of Anthyllis vulneraria L it was effective. Scarification was effective for commercial hard seed species like Lotus corniculatus L in our case, but it was not effective for Agrimonia eupatoria L. The aim of the treatments was to select those species which can be seed in the same time, will be easier applied to soil and climatic condition of the experiment site and to determine effect of pre-treatments on germination % of seeds of tested species.

Aggregation of a symmetrical metalloporphyrin. Concentration and temperature dependence of the absorption and magnetic circular dichroism spectra of dilute zinc octamethyltetrabenzporphyrin solutions

Absorption and magnetic circular dichroism (mcd) spectra of toluene solutions of zinc octamethyltetrabenzporphyrin, Zn(OMBP), exhibit marked concentration and temperature dependence. Monomeric Zn(OMBP), 1, characterized by a 429 nm Soret band, dominates at low concentrations (10−7 M, 300 K) and higher temperatures (10−5M, 320 K) in toluene solution. Decreasing temperatures (320 to 235 K for a 10−5 M solution) and increasing concentrations (10−7 M to 10−4M, 300 K) result in 8–10 nm red shifts in this band. These spectral changes are attributed to the concurrent formation of a species 2 with a low extinction coefficient and another compound, 3, with λmax at 439 nm. At the highest concentrations (10−3 M) and lowest temperatures (225–190K) used, a dramatic blue shift (439 to 422 nm) due to a fourth species (4) is observed. All the spectral changes observed are completely reversible. In addition, and consistent with self-association, species 2, 3, and 4 are formed at higher temperatures as the concentration is increased. Possible aggregate structures are proposed and evidence is presented for a novel Zn—N (pyrrole) intermolecular bond.