ArielRad: the Ariel radiometric model

ArielRad, the Ariel radiometric model, is a simulator developed to address the challenges in optimising the space mission science payload and to demonstrate its compliance with the performance requirements. Ariel, the Atmospheric Remote-Sensing Infrared Exoplanet Large-survey, has been selected by ESA as the M4 mission in the Cosmic Vision programme and, during its 4 years primary operation, will provide the first unbiased spectroscopic survey of a large and diverse sample of transiting exoplanet atmospheres. To allow for an accurate study of the mission, ArielRad uses a physically motivated noise model to estimate contributions arising from stationary processes, and includes margins for correlated and time-dependent noise sources. We show that the measurement uncertainties are dominated by the photon statistic, and that an observing programme with about 1000 exoplanetary targets can be completed during the primary mission lifetime

Molecular and phenotypic characterisation of novel Phaeoacremonium species isolated from esca diseased grapevines

Petri disease and esca are very destructive grapevine decline diseases that occur in most countries where grapevine (Vitis vinifera) is cultivated. Phaeoacremonium species are among the principal hyphomycetes associated with symptoms of the two diseases, producing a range of enzymes and phytotoxic metabolites. The present study compared the phylogeny of a global collection of 118 Phaeoacremonium isolates from grapevines, in order to gain a better understanding of their involvement in Petri disease and esca. Phylogenetic analyses of combined DNA sequence datasets of actin and β-tubulin genes revealed the presence of 13 species of Phaeoacremonium isolated from esca diseased grapevines. Phaeoacremonium aleophilum was the most frequently isolated species with an incidence up to 80 % of all isolates investigated. Species previously described mainly as human pathogenic species, namely Pm. alvesii, Pm. griseorubrum and Pm. rubrigenum are newly reported on grapevine from Turkey, Italy and Croatia, respectively. Phaeoacremonium viticola and Pm. scotyli represent new records for Italy, as well as Pm. mortoniae for Hungary and Croatia. In addition, four new species of Phaeoacremonium, namely Pm. croatiense, Pm. hungaricum, Pm. sicilianum and Pm. tuscanum are newly described from grapevine based on morphology, cultural characteristics, as well as molecular phylogeny

Growth reduction in root-restricted tomato plants is linked to photosynthetic impairment and starch accumulation in the leaves

The mechanisms responsible for reduced shoot growth due to restricted root growth is still not fully understood. Therefore, this investigation was planned to determine the morphological and physiological changes induced in response to root restriction conditions and to determine the time frame within which these changes occurred. In particular, this research aims to evaluate the effect of root restriction on growth, leaf gas exchange parameters, carbohydrate production and water relations in tomato (Solanum lycopersicum L.). Our results show that growth reduction by root restriction is mainly linked to a photosynthetic impairment, caused by a concurrent limited stomatal conductance (probably driven by stomatal factors and hormonal substances) together with a strong accumulation of starch in the tissues, which led to a feedback inhibition of the photosynthetic process