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Pinus nigra(Austrian pine) is a tree widely planted in central and southern Europe in the reforestation of areas with poor soils. One of the major constrains ofP. nigrais a fungal disease caused bySphaeropsis sapineawhich causes shoot tip dieback and tree mortality. This paper describes a real-time quantitative PCR assay based on the partial sequence of the small subunit ribosomal RNA ofS. sapineato detect and quantify DNA of the fungal pathogen inS. sapineainoculated shoots. The study found that real-time quantitative PCR was a reliable technique to diagnose this disease and suggests that it can also be used to study fungal behaviour in host tissue and particularly to quantify fungal growth in the latent or endophytic phase. [ABSTRACT FROM AUTHOR]

Leaves of olive and oleander were sprayed with suspensions of their homologous strains (PVBa230 and ITM519, respectively) of Pseudomonas syringae subsp. savastanoi and examined by SEM. It was found that both strains multiplied on the lower surface of the leaves of both species. Preferred sites for survival and multiplication were the shields of peltate hairs on olive and the stomatal pits on oleander. The findings suggest that, at least in olive leaves, some bacteria entered the leaf tissue through the stomata but that this was not important since cells which entered the host did not cause any disease symptoms. Cells of both strains were agglomerated and cells of ITM519 were further attached to the surface of the leaf hairs on oleander by fibrillar material. Inoculated leaves did not show any disease symptoms except at leaf abscission scars on olive plants where leaves had been excised prior to inoculation. It is suggested that on both olive and oleander preexisting wounds are necessary for symptoms to develop. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Phytopathology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Phytopathology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Over 85 % of total cellular fatty acids of 30 strains of P. syringae pv. savastanoi, grown for one day at 28 °C on King's medium B (KB) agar, were 12 : 0 (5.0 %), 16 : 0 (27.5 %), 16 : 1 (36.7 %) and 18 : 1 (16.8 %). Three hydroxy-substituted fatty acids comprised 7.2 % of the total and 22 other minor components, each occurring at concentrations of less than 1 %, comprised an additional 4 %. Three percent were unidentified components. Cells grown for 3 and 6 days on KB agar contained lower concentrations of the unsaturated 16 : 1 (30.4 and 21.1 %, respectively), and higher concentrations of branched-chain and cyclopropane fatty acids than one-day old cells. No consistent differences in fatty acid composition could be detected between virulent and avirulent strains, nor between pv. savastanoi and other pathovars of P. syringae. However, when cells were grown on a chemically- defined medium for 6 days, concentrations of 16 : 0 and a tentatively-identified 17-carbon hydroxy fatty acid were higher, and those of 12 : 0 and 16 : 1 were lower in strains from Fraxinus than from Olea. P. fluorescens (7 strains) and P. viridiflava (6 strains) could be differentiated from each other but not from P. syringae. [ABSTRACT FROM AUTHOR]