Using Verticillium albo-atrum WCS850 to control Dutch elm disease

Approximately 100 years after the first introduction of Dutch elm disease (DED) in Europe, an effective commercial biocontrol product is available to protect susceptible elm trees against DED transmission by beetles. Injection of trees with conidiospores of the fungus Verticilium albo-atrum isolate WCS850, product name DutchTrig®, reduces infection to less than 0.2% of treated trees. This biocontrol agent, its mode of action, application, efficacy and limitations in controlling DED are described in this chapter.

Amino acid changes during the early stages of tomato wilt disease (Verticillium albo-atrum)

Soil-borne pathogens such as Verticillium species, invade into the roots of many herbaceous and woody hosts. The xylem environment supplies these pathogens with a continuous flow of nitrogen-rich nutrition. Detailed quantitative increases in amino acids in the stems, petioles, leaflets and roots of young tomato plants infected with Verticillium. albo-atrum the causal agent of wilt disease, are described in this paper for the first time. Results focus in particular on the vascular environment prior to the emergence of visual symptoms. Total amino acid concentrations in infected stems and petioles increased substantially at 144 and 216 h after inoculation. This effect was evident in leaflets at 216 h after inoculation. By 216 h most amino acid concentrations were substantially increased in stems, petioles and leaflets of infected plants relative to healthy controls. Earlier at 144 h in stems substantial increases were recorded for aspartic acid, threonine, serine, glutamic acid, glycine and ethanolamine. A similar picture emerged for petioles with the addition of increases in proline but not glycine. Amino acids increasing substantially in infected leaflets at 216 h were aspartic acid, glutamic acid and ethanolamine. In the infected roots there was relatively little difference in amino acid concentrations relative to healthy controls with the particular exceptions of proline and ethanolamine. By 18 days (432h), when visual symptoms were well advanced marked increases in amino acid concentrations were found for threonine, serine, α-alanine, valine, methionine, iso-leucine, leucine, tyrosine, ethanolamine, ornithine, lysine, histidine and arginine.

New records of seven fungal species for Bangladesh

From three farming stages of Arthrospira platensis (Nordstedt) Gomont [Spirulina platensis (Gomont) Geitler], seven fungal species, namely, Cladosporium varians Braun, Melnik & K. Schub., Fusarium trichothecioides Wollenw., Geotrichum candidum Link, Mucor circinelloides Tiegh., M. hiemalis Wehmer, Penicillium frequentans Westling and Verticillium albo-atrum Reinke & Berthold were recorded for the first time from Bangladesh.Bangladesh J. Plant Taxon. 23(1): 1-6, 2016 (June)

Effect of saprophytic fungi on tomato pathogens: Fusarium oxysporum f. lycopersici and Verticillium albo-atrum in the soil substratum

The biotic relations were studied in garden alfalfa soil between <i>Fusarium oxysporum F. Lycopersici</i> and <i>Verticillum albo-atrum</i> and saprophytic soil fungi. The presence of the latter had an inhibitory effect on the development of pathogens and the pathologic symptoms in the tomatos. It was found that real development of plants. A change of the glasshouse soil from under alfalfa may be favourable for preventing infection of tomatoes.

Studies on alfalfa diseases caused by fungi. II

The specific and quantitative composition of the microflora was investigated within the range of the roots of 1-, 2- and 3-year plants in alfalfa cultures with the aim of finding effective new methods of control or prevention of diseases of alfalfa caused by <i>Verticillium albo-atrum</i> and <i>Ascochyta imperfect</i>. The biotic realations between the most numerous saprophytes found on the same sites and the above named pathogens were also studied.