Search results for "Spores"
showing 6 items of 96 documents
Distributions of the growth rate of the germ tubes and germination time of Penicillium chrysogenum conidia depend on water activity
2008
The effects of water activities for sporulation (a(wsp)) and germination (a(wge)) on the distributions of the growth rate of the germ tubes (mu) and the germination time (t(G)) of Penicillium chrysogenum conidia were determined by monitoring the length of the same germ tubes throughout the experiments automatically. No relationship between the individual t(G)'s and mu's could be established. Irrespective of the water activity for germination, mu was greater and t(G) was less for conidia produced at 0.95a(wsp) than that at 0.99a(wsp). At 0.99 a(wge) the mean and the standard deviation of t(G) were smaller than those obtained at 0.95a(wge). At 0.99a(wge), normal distributions for mu and t(G) …
Lag time for germination of Penicillium chrysogenum conidia is induced by temperature shifts.
2013
In the environment, fungal conidia are subject to transient conditions. In particular, temperature is varying according to day/night periods. All predictive models for germination assume that fungal spores can adapt instantaneously to changes of temperature. The only study that supports this assumption (Gougouli and Koutsoumanis, 2012, Modelling germination of fungal spores at constant and fluctuating temperature conditions. International Journal of Food Microbiology, 152: 153-161) was carried out on Penicillium expansum and Aspergillus niger conidia that, in most cases, already produced germ tubes. In contrast, the present study focuses on temperature shifts applied during the first stages…
Generation of homozygosity and genome fixation in pea (Pisum sativum L.)
2013
Pea cultivars are nearly homozygous and thus homogeneous when they are released. The traditional method of selfing is slow and inefficient, taking up to ten generations of inbreeding following a cross to achieve a high level of homozygosity. Current single-seed-descent (SSD) methodologies enable a maximum of three generations per year to be developed in pea. Doubled haploidy and an in vitro based modified SSD technology have been utilised in many important crops for the rapid achievement of homozygosity, and thus acceleration of the breeding process. In pea, due to the lack of robust protocols, none of these technologies is routinely used in a breeding program. The aim of this study was to …
Assessment of antifungal activity of extracts from nettle (Urtica dioica L.) against Alternaria solani = Ocena aktywności przeciwgrzybowej ekstraktów…
2015
(Urtica dioica L.) w stężeniach 2,5, 5,0, 10,0, 20,0, 40,0% wobec fitopatogennego szczepu Alternaria solani. Aktywność przeciwgrzybową ekstraktów z pokrzywy określono w oparciu o indeks tempa wzrostu grzybni oraz indeks kiełkowania zarodników. W badaniach określono również wpływ metod sterylizacji testowanych wyciągów na ich aktywność. Na podstawie uzyskanych wyników wykazano, iż ekstrakty sterylizowane parą wodną pod ciśnieniem nie wykazują aktywności przeciwgrzybowej. W przypadku ekstraktu z korzenia, który charakteryzował się większą aktywnością inhibicyjną, uzyskano zaledwie 7% redukcję tempa wzrostu grzybni. Natomiast ekstrakt z korzenia poddany sterylizacji przez sączenie ograniczał o…
Standardisation of methods for assessing mould germination: a workshop report.
2006
International audience; The first workshop on predictive mycology was held in Marseille, France, 2–4 February 2005 under the auspices of the French Microbiological Society. The purpose of the workshop was to list the different techniques and definitions used by scientists for assessing mould germination and to evaluate the influence of the different techniques on the experimental results. Recommendations were made when a large consensus was obtained. In order to facilitate the study of germination, alternative methods to microscopic examination were examined.
Development of Henneguya zschokkei (Myxozoa: Myxosporea) actinospores in oligochaetes and plasmodia in whitefish Coregonous lavaretus
2013
The aim of this study was to describe the life cycle of H. zschokkei by observing the development of actinospores in oligochaete and the morphological development of H. zschokkei cysts in whitefish. Laboratory observation of seasonal occurrence of actinospores sampled from oligochaetes from RTKL Tervo Fish Farm revealed 6 types of actinospores from collective groups of Triactinomyxon, Raabeia and Aurantiactinomyxon in 2010, and 3 types of actinospores in 2011. Both years showed similar patterns with the release of actinospores peaking in both summer (June and July) and winter (January and February) times. The infection experiment was not successful in infecting Coregonus lavaretus with myxo…