SAIN Invasive Plant Pests Resource Collection for: Common daffodil
Species (scientific name): Narcissus pseudonarcissus
| Title: Inhibition of Narcissus pseudonarcissus phytoene desaturase by herbicidal 3-trifluoromethyl-1,1'-biphenyl derivatives. |
| Author: Laber-Bernd ; Usunow-Gerlinde; Wiecko-Elzbieta; Franke-Wilfried; Franke-Heinrich; Koehn-Arnim. |
| Source: Pesticide-Biochemistry-and-Physiology. 63 (3): 173-184. |
| Source Type: Journal |
| Publication Date: 1999 |
| Abstract: A synthesis program directed to the discovery of novel bleaching herbicides led to the preparation of substituted 3-trifluoromethyl-1,1 -benzoxazoles and 3-trifluoromethyl-1,1 -biphenyls with thiazole-, thiadiazole-, and benzthiazole substituents. Herein, we show that these compounds interfere with the biosynthesis of colored carotenoids by inhibiting the enzyme phytoene desaturase. IC50 values for inhibition of phytoene desaturase have been determined for 62 derivatives. Several new compounds were found that inhibited phytoene desaturase up to 400-fold more potently than the commercial bleaching herbicide norflurazon. The derived relationships between chemical structure and enzyme inhibition were used to generate a model of the proposed herbicide binding site. The implication that phytoene desaturase is the target site for the substituted 3-trifluoromethyl-1,1 -benzoxazole and biphenyl classes of herbicides is supported by a significant correlation of the IC50 values for inhibition of phytoene desaturase with the biological activity in preemergence upland tests in the greenhouse. |
| Title: Population dynamics of the wild daffodil (Narcissus pseudonarcissus): IV. Clumps and gaps. |
| Author: Barkham-J-P. |
| Source: Journal-of-Ecology. 1992; 80 (4) 797-808. |
| Source Type: Journal |
| Publication Date: 1992 |
| Abstract: Two experiments were carried out on an ancient English deciduous woodland to determine the relationship between the occurrence of gaps-unoccupied spaces-in the ground layer in the ability of Narcissus pseudonarcissus to occupy them. In the first experiment, seeds and bulbs of Narcissus were planted into gaps and their fates were followed for 10 years. A second experiment examined the survivorship, mortality, clonal growth and flowering of bulbs and seeds grown in pots at different densities in open and shaded sites. In the first experiment, bulbs planted into gaps in a shaded site performed similarly to controls (naturally established individuals). Plants growing from seeds or seedling died, as did the controls. It is concluded that the existence and persistence of gaps is a function of the demography of the species rather than of an inherently inimical environment. In the second experiment, survivorship of established bulbs showed a more-or-less constant probability of death, whilst that of seedlings showed declining probability of mortality. Clonal growth rate was density-dependent but establishment of plants from seeds was not. Mortality was density-independent, except at high density in open ground. Clonal growth was twice a fast in open ground as in shaded sites. The results of these experiments are brought together in a scheme suggesting that a wide of densities of N. pseudonarcissus is possible at the site due to the changing balance between reproduction and mortality in a periodically disturbed environment. The implications of this conclusion are explored in relation to ground occupancy and the development of mixtures in the ground flora of ancient British woodlands. |
< Back
Next >
Back To Invasives Common Name Index
|
