Occurrence of the Hyperparasite Ampelomyces quisqualis on Golovinomyces neosalviae (Erysiphaceae), Causal Agent of Powdery Mildew on Common Sage (Salvia officinalis)

Abstract

Hamzeh, S., W. Naffaa and M.F. Azmeh. 2022. Occurrence of the Hyperparasite Ampelomyces quisqualis on Golovinomyces neosalviae (Erysiphaceae), Causal Agent of Powdery Mildew on Common Sage (Salvia officinalis). Arab Journal of Plant Protection, 40(2): 158-163. https://doi.org/10.22268/AJPP-040.2.158163 Ampelomyces quisqualis, the oldest mycoparasite of powdery mildew (PM), has been widely studied due to its potential in biocontrol. Many strains of this hyperparasite have been experimented worldwide and some of them were successfully applied for biocontrol, but others have been less efficient. No previous identification of Ampelomyces strains has been done in Syria, but some isolates were morphologically identified in the coastal region. There was no indication of Ampelomyces occurrence in any other location in Syria. During this three years survey (2019–2021), 73 plant samples were collected from five governorates, including coastal and southern regions in Syria. Ampelomyces pycnidia were detected in five samples from the coastal area and a new unpredictable finding of Ampelomyces sp. was found in southern Syria. This new occurrence of Ampelomyces isolate (S.ham82) is documented on a new mycohost; Golovinomyces neosalviae, the causal agent of PM on common sage (Salvia officinalis). Successful isolation of S.ham82 on PDA was conducted and parasitic activity was assessed by artificial inoculation using In vitro detached leaf assay. Morphological characteristics of this isolate were determined and compared with isolate Bah1 from the coastal region. Ampelomyces sp. (S.ham82) pycnidia size were 77.44 (±17.16) x 25.28 (±6.12) µm in natural host, 125.27 (±42.34) x 115.95 (±40.14) µm, 189.51 (±60.06) x 167.64 (±52.41) µm on PDA media pre and post artificial inoculation, respectively, and 88.24 (±20.05) x 27.98 (±5.68) µm on inoculated detached leaves. Conidia were also morphologically characterized and measured 8.11 (±0.87) x 3.88 (±0.51) µm in natural host, 8.86 (±1.65) x 3.18 (±0.80) µm in PDA pre and post artificial inoculation, respectively, and 7.82 (±0.69) x 3.61 (±0.37) µm in inoculated detached leaves. To our knowledge, this is the first report of the natural occurrence of Ampelomyces sp. in G. neosalviae on Saliva officinalis. Keywords: Ampelomyces sp., Common sage, Golovinomyces neosalviae, Syria.