Non-soluble particles trapped in natural ice (glaciers, permafrost, hail) provide valuable information about the environments in which they were formed. The extraction of the particles is usually ...carried out through the melting of ice and subsequent filtering of the water obtained. Here, a novel methodology for extracting ice particles from the solid-phase is presented, which is efficient, low-cost in infrastructure, and minimizes possible sources of contamination. This methodology of adapted sublimation particle separation allows to determine the spatial distribution and concentration of non-soluble particles, as well as their sizes (without the limitations of filtration), their shape, structure and elementalchemical composition. The method is in this case applied to hail collected during the program COSECHEROS, which has a medium-sized particle of 40μm at its center.
Mycoviruses that induce hypovirulence in phytopathogenic fungi are interesting because their potential use as biological control agents of the plant diseases caused by their fungal hosts. The ...recently identified chrysovirus Fusarium oxysporum f. sp. dianthi virus 1 (FodV1) has been associated to the induction of hypovirulence in
f. sp. dianthi, the forma specialis of
that causes vascular wilt in carnation (
). In this work, we have used confocal laser scanner microscopy and two isogenic GFP-labeled strains of
f. sp.
infected (V
) and not infected (V
) with the Fusarium oxysporum f. sp. dianthi virus 1, respectively, to analyze the effect of mycovirus FodV1 on the plant colonization pattern of its fungal host. Results demonstrate that FodV1-viral infection affects the speed and spatial distribution of fungal colonization into the plant. Initial stages of external root colonization were similar for both strains, but the virus-free strain colonized the internal plant tissues faster than the virus-infected strain. In addition, other differences related to the specific zone colonized and the density of colonization were observed between both
f. sp.
strains. The hyphae of both V
and V
strains progressed up through the xylem vessels but differences in the number of vessels colonized and of hyphae inside them were found. Moreover, as colonization progressed, V
and V
hyphae propagated horizontally reaching the central medulla but, while the virus-free strain V
densely colonized the interior of the medulla cells, the virus-infected strain V
appeared mainly in the intercellular spaces and with a lower density of colonization. Finally, the incidence of FodV1-viral infections in a collection of 221 isolates sampled between 2008 and 2012 in the geographic area where the originally infected isolate was obtained has been also analyzed. The very low (<2%) incidence of viral infections is discussed here. To the best of our knowledge, this work provides the first microscopic evidence about the effect of a hypovirulence-inducing mycovirus on the pattern of plant colonization by its fungal host.
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