Search results for "Seed dormancy"
showing 10 items of 14 documents
Hydroperiod length as key parameter controlling seed strategies in Mediterranean salt marshes: The case of Halopeplis amplexicaulis
2018
Abstract The comprehension of plant biology and the response to the environment is fundamental to achieve the optimal skills to manage and conserve the fine equilibrium between biotic and abiotic parameters regulating natural biodiversity in salt marshes. The behaviour of annuals living in these stressful conditions is poorly understood and constitutes a good model for a better understanding of this relationship. We thus identified the determinant environmental factors involved in population survival of Halopeplis amplexicaulis, a threatened annual species inhabiting salt marshes. To achieve this objective, maternal climatic parameters were analyzed in seeds collected in different years, an…
Artificial germination activation of Dialium corbisieri by imitation of ecological process.
2013
11 pages; International audience; Species of the gender Dialium commonly are trees found in Central African rainforests. They produce tasty sugary fruits, feeding numerous frugivores, but are, despite their valuable nutritional value, rarely exploited by humans. A potential reason for this could be the complexity of symbiotic dependence between trees and pollinators, germination activators, and dispersers causing problems in ancestral and contemporary domestication. We investigated Dialium corbisieri reproduction in the Democratic Republic of the Congo, Bandundu Province. Here we give a key for an artificial activation of germination of these trees ecologically adapted to the digestive syst…
Prediction of germination rates of weed species: Relationships between germination speed parameters and species traits
2011
International audience; In fields, the timing of weed emergence flushes is mostly related to the timing and rate of seed germination, which depend on seed dormancy level, soil temperature and water potential conditions as well as soil tillage and crop sowing date. Seed germination parameters are essential in weed dynamics models to account for the effects of soil conditions on weed demography. Since these parameters are difficult to measure, our objective was to test the possibility of estimating them from easily accessible information. Seed germination parameters (germination lag-time, time to mid-germination and mid-germination rate) were measured or collected from the literature for 25 w…
Seed bank dynamics of an invasive plant, Ambrosia artemisiifolia L.
2008
AbstractThe seed-bank dynamics ofAmbrosia artemisiifolia(Asteraceae), an annual invasive plant introduced from North America to Europe, were studied in nine French populations developing in field crops, set-asides or wastelands. The vertical distribution of seeds was studied in two different depth sections (0–5 cm and 5–20 cm), and the spatial horizontal pattern of distribution was analysed for two selected field-crop and set-aside populations. The proportions of dormant, non-dormant and dead seeds, as well as the changes in seed-bank dormancy over time, were evaluated. Natural seedling recruitment and its variation under different disturbance treatments in competitive set-asides were also …
Germination and emergence of Neslia paniculata (L.) Desv.
2019
Abstract Seed characteristics, either in size or in structure, can affect germination, hence the emergence of a plant species. In the present work germination and emergence of Neslia paniculata, a Brassicaceae species that produces fruits containing one seed covered by a hard fruit coat, was studied. Germination experiments of seed with and without the fruit coat were performed at constant temperatures from 5 to 23 °C under controlled conditions and germination was measured daily. Additionally, seeds were sown in the field and emergence was periodically followed in three sites: Almenar (Spain), Morris (USA) and Riga (Latvia). Both germination and emergence were modelled with Boltzmann and W…
Old sleeping Sicilian beauty: seed germination in the palaeoendemic Petagnaea gussonei (Spreng.) Rauschert (Saniculoideae, Apiaceae).
2015
Petagnaea gussonei (Apiaceae) is a perennial herbaceous species endemic to northeast Sicily (Nebrodi Mountains). It is considered a remnant of the Sicilian Tertiary flora, and is endangered according to the Red List. There is no information in the literature about the germinability of its seeds, even though seed production is know to occur. The aim of this study was to obtain data to better understand seed germination of this species and its biological implications. Thus, several approaches were employed: vitality analyses, gibberellic acid supply, germination and soil microbial flora analyses via end-point and qPCR. The results suggest that seed germination occurs after ca. 1.5 years at a …
Morphology, anatomy and germination response of heteromorphic achenes of Anthemis chrysantha J. Gay (Asteraceae), a critically endangered species
2011
[EN] This study demonstrates that Anthemis chrysantha, a 'Critically Endangered' annual plant, produces two morphs of achenes: white and dark achenes, which differ in size, mass, anatomy and germination behaviour. Fresh white achenes germinated at all temperatures assayed from 10 to 25 degrees C in both continuous darkness and 12-h photoperiod, ranging between 24% at 25 degrees C in darkness and 89% at 12/20 degrees C in light, whereas fresh dark achenes did not germinate under any temperature or light conditions. To identify differences in dormancy type between the two morphs, germination of dry-stored achenes, and achenes stratified at 5 or 25 degrees C for 2 months were tested in both da…
Genecological and isozyme studies in Senecio vernalis Waldst. & Kit. and S. vulgaris L. var. vulgaris (Asteraceae) from Central Europe and Israel
1995
Summary Genecological evidence and evidence obtained from an isozyme survey suggest a considerable amount of intraspecific differentiation in Senecio vernalis . Plants of this species from Israel were found to differ strikingly from those of C European (German) origin in most of the traits investigated, e.g., in the possession of pronounced seed dormancy, which seems to be governed by a single gene, a shorter life cycle, lack of rosette growth correlated with stem elongation prior to budding, a larger number of smaller capitula with fewer (disc) florets, and an ephemeral habit with plants only flowering soon after the first winter rains. Both accessions achieved a similar reproductive poten…
The Genetics of Evolutionary Change in Senecio vulgaris L.: A QTL Mapping Approach
2001
: The cosmopolitan weed Senecio vulgaris var. vulgaris is likely to have originated from the non-weedy S. vulgaris ssp. denticulatus from which it differs by showing no seed dormancy, by completing its life cycle from germination to seed formation much faster and by lacking ray florets. An F2 generation of 120 individuals obtained through selfing of one hybrid individual between var. vulgaris and ssp. denticulatus was used to construct a linkage map based on RAPD polymorphisms and the presence or absence of ray florets. This linkage map was used for a QTL analysis of 12 characters distinguishing the two taxa. For seven of these 12 characters, three significant QTLs could be found. One of th…
Opportunistic Germination Behaviour of Gypsophila (Caryophyllaceae) in Two Priority Habitats from Semi-arid Mediterranean Steppes
2011
Gypsophila tomentosa and G. struthium are closely related species, characteristic of two European priority habitats, salt and gypsum inland steppes, respectively. Germination strategies of the two taxa were investigated in plants from two nearby populations, growing under the same climatic conditions but on different types of soil, and belonging to different plant communities. Their germination patterns were studied at five constant temperatures in darkness: 5oC, 10oC, 15oC, 20oC and 25oC, and the base temperature and the thermal time requirement were calculated. As the distribution area of both species is subjected to a Mediterranean continental climate with significant differences between…