Search results for "Germination"
showing 10 items of 251 documents
Phytotoxic effects of Lantana camara, Eucalyptus camaldulensis and Eriocephalus africanus essential oils in weeds of Mediterranean summer crops
2009
Abstract The essential oil composition of Lantana camara , Eucalyptus camaldulensis and Eriocephalus africanus was analyzed by means of GC and GC–MS and bioassayed in order to determine their activity against Amaranthus hybridus and Portulaca oleracea . E. camaldulensis essential oil, with spathulenol as the main compound, was the most effective, completely inhibiting germination and seedling growth on both weeds. The essential oil of E. africanus , rich in artemisia ketone, showed activity similar to that of E. camaldulensis on A. hybridus , but it was not so effective against P. oleracea , and L. camara essential oil, with high percentages in sesquiterpene hydrocarbons, also showed higher…
Tanzawaic acids I-L: Four new polyketides from Penicillium sp. IBWF104-06.
2014
Four new polyketides have been identified in culture filtrates of the fungal strain Penicillium sp. IBWF104-06 isolated from a soil sample. They are structurally based on the same trans-decalinpentanoic acid skeleton as tanzawaic acids A–H. One of the new compounds was found to inhibit the conidial germination in the rice blast fungus Magnaporthe oryzae at concentrations of 25 μg/mL.
Breeding system and conservation strategy of the extremely endangered Cistus carthaginensis Pau (Cistaceae) of Spain
2001
Cistus carthaginensis is one of the most endangered plants in Europe: at present there exist only a few individuals in Murcia and one in Valencia (SE and E Spain). To design an adequate conservation strategy able to avoid the extinction of this species, various aspects of its reproductive biology were studied. The extreme rarity of C. carthaginensis is not related to problems of development and/or fertility of pollen or ovules produced by the few existing specimens. Meiosis in the pollen mother cells is always regular and chromosome segregation is completely equilibrated in the male gametes. Pollen and ovule production is high and similar to that reported for other related species of Cistus…
Inorganic polyphosphates in the developing freshwater spongeEphydatia muelleri: Effect of stress by polluted waters
1996
Relatively high amounts of inorganic polyphosphates (approximately 55 μg of polyphosphate/g of wet weight) were found in the freshwater sponge Ephydatia muelleri, particularly in the gemmules (260 μg/g). Here we report that the polyphosphate content of this sponge changes during development and in response to adverse environmental conditions. Germination and hatching of gemmules of E. muelleri is accompanied by a strong decrease (by 94% at day 2) in polyphosphate level and a rise in exopolyphosphatase activity. On the other hand, induction of gemmulogenesis by theophylline results in an increase (by 61%) in polyphosphate content of sponge tissue. An increase in polyphosphate content and a d…
Coumarin derivatives from Pedilanthus tithymaloides as inhibitors of conidial germination in Magnaporthe oryzae
2012
In a screening for inhibitors of infection-related morphogenesis in the rice blast fungus Magnaporthe oryzae, a series of 10 coumarin derivatives were isolated from Pedilanthus tithymaloides (Euphorbiaceae). Seven of these compounds turned out to be known while three represent previously unreported natural products. Their structures were established on the basis of spectroscopic data and X-ray crystallography. Nine out of 10 coumarin derivatives were found to inhibit conidial germination in the phytopathogenic fungus at low concentrations.
GENETIC AND PHYSIOLOGICAL STUDIES OF THE EFFECT OF LIGHT ON THE DEVELOPMENT OF THE MOSS, PHYSCOMITRELLA PATENS
1978
Abstract The germination of Physcomitrella patens spores only occurs when wet spores are exposed to light. Depending on their ripeness, spores require from 44 to 64 h illumination to bring about maximum germination. There is a lag period of about 15 h between the reception of sufficient light to elicit germination before germination can be observed. Wavelengths in the range 640-680 nm are much more effective in inducing germination than longer or shorter wavelengths, but far-red reversal of red light induction of germination has not been demonstrated. Light also has very marked effects on protonemal and gametophore development. In darkness, only caulonemata are produced, and these grow nega…
Effect of analogues of plant growth regulators on in vitro growth of eukaryotic plant pathogens
2004
FGA (furfurylamine; 1,2,3,4 tetra-O-acetyl-β-d-glucose; adipic acid monoethyl ester), a chemical mixture of three analogues of plant growth regulators that increases the protection of tomato plants against phytopathogens, was demonstrated to have direct antimicrobial activity. It reduced the growth in vitro of the filamentous fungi Alternaria solani and Botrytis cinerea, and the oomycetes Phytophthora capsici and Phytophthora citrophthora (ED50 0·18–0·26% w/v, depending on species). The components of this mixture were also active against these phytopathogens, but sensitivity to the compounds was different for each pathogen. Adipic acid monoethyl ester (E) showed the highest and widest range…
Phytotoxic effects of essential oils of Nepeta curviflora Boiss and Nepeta nuda L.subsp. albiflora growing wild in Lebanon
2009
The chemical composition of the essential oils of two Nepeta species collected in Lebanon was studied by means of GC and GC-MS analysis. The essential oil from N. curviflora Boiss. contained high amounts of β-caryophyllene (41.6%), caryophyllene oxide (9.5%), (E)-β-farnesene (6.2%) and (Z)-β-farnesene (4.8%); in the oil from N. nuda L. subsp. albiflora (Boiss.) Gams. collected in Laklouk the main compounds were β-bisabolene (11.8%), pulegone (10.8%), (E,Z)-nepetalactone (8.0%), (E)-β-farnesene (7.1%) and caryophyllene oxide (6.9%), while N. nuda L. subsp. albiflora collected in Tannourine Cedar Forest contained high percentages of hexadecanoic acid (10.1%), β-bisabolene (7.8%), caryophyllen…
Genetic basis of speed of development in Senecio vulgaris L var. vulgaris, S. vulgaris ssp. denticulatus (O.F. Muell.) P.D. Sell, and Senecio vernali…
1996
The genetic basis of differences in speed of development from germination to first bud formation was investigated in Senecio vulgaris var. vulgaris and S. vulgaris ssp. denticulatus, and also in S. vernalis sampled from Israel and Germany. In the case of S. vulgaris, F2 segregation analysis and the recovery of very late and very early lines from extreme F2 phenotypes showed that differences can be explained by a single major gene model, whereas segregation data from F2 and backcross progenies in S. vernalis are not incompatible with a digenic model of inheritance. Senecio vernalis from Israel and S. vulgaris var. vulgaris reached the different developmental stages in a substantially shorter…
Seed germination in the Sicilian subspecies ofDianthus rupicolaBiv. (Caryophyllaceae)
2012
Abstract Five populations belonging to three subspecies of Dianthus rupicola Biv. (D. rupicola subsp. rupicola, D. rupicola subsp. aeolicus, and D. rupicola subsp. lopadusanus) and growing in different geographical areas of Sicily were tested for seed germination at various temperatures. All populations showed high germination rates with an optimum temperature between 15°C and 25°C. Efficient seed germination might contribute significantly to the preservation of these subspecies which are currently exposed to several environmental threats.