Oospores were formed in the leaves within 6 days, while sporangia were not produced. By monitoring disease progress in fields with a different cropping history of leek, it could be deduced that P. porri survives in soil for up to 4 years. Disease progress during three consecutive years Selleck Roscovitine was correlated with average daily rainfall in the infection period. Disease incidence on leek was reduced when rain splash was excluded by growing the plants in an open hoop greenhouse. Based on these findings, we propose a disease cycle for P. porri in which oospores germinate in puddles, and zoospores reach

the leaves by rain splash and survive in water in the leaf axils, from where they infect the plant by direct penetration or via stomata. When conditions become unfavourable, oospores are produced in the leaves which again reach the soil when leaves decay. Secondary spread of the disease by sporangia does not seem to be important. “
“Mycelial compatibility is assayed mainly by pairing mycelial plugs of field Selleckchem AZD5363 isolates on Petri dishes with agar media. Although methodologically simple, mycelial compatibility testing requires an artificial growth medium that permits the identification of compatible and incompatible interactions.

In this work, several growth media were studied to assess consistently mycelial interactions between Sclerotium rolfsii isolates. A modification of Patterson’s medium with an increment of 25% glucose from the original concentration at a rate of 23.4 g/l and amended with 180 μl/l of red food colouring was the most effective combination for enhancing the size, density and distinctiveness of the aversion zone between incompatible isolates. This medium allowed the unequivocal identification of compatible

and incompatible reactions of a set of five S. rolfsii isolates, which could be determined quickly after 5 days of incubation in the dark at 25°C. This new formulation improved significantly MCE公司 and consistently the assessment of the aversion zone reaction that was visible as a red line on the colony reverse as compared to that assessed using previous media formulations, for which the visualization of aversion zones was scarcely discernible. The utility of the improved growth medium was validated by microscopic observations of the contact area of hyphal pairings between isolates of S. rolfsii in microscope slide cultures. “
“Prior to 2007, late blight was not reported as a serious threat to tomato cultivation in India although the disease has been known on potato since 1953. During the July–December cropping season of 2009 and 2010, severe late blight epidemics were observed in Karnataka state of India, causing crop losses up to 100%.