Factors Promoting Pycnidia Production of Didymella bryoniae, the Causal of Gummy Stem Blight in Cucurbits | ||||
| Egyptian Journal of Phytopathology | ||||
| Article 11, Volume 45, Issue 1, June 2017, Page 173-187 PDF (644.19 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ejp.2017.89736 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| Abdel-Fattah El-Wakil* ; Amal Khalil; Ibrahim El -Abbasi | ||||
| Seed Pathol. Res. Dept., Plant Pathol. Res. Inst., A.R.C., Egypt | ||||
| Abstract | ||||
| Gummy stem blight in Cucurbitacea caused by the pathogen Didymella bryoniae under high humid conditions was previously recorded in many countries. In Egypt, the disease was observed for the first time on cantaloupe grown under sprinkling irrigation system in El-Bostan (Beheira governorate). Percentage of diseased plants ranged from 10 to 15% in the surveyed fields. Many isolation trials were carried out without success in obtaining conidial structures; only undistinguished mycelium was obtained. Among 9 natural media tested, V-8 Agar medium (V-8A) was the fastest in producing the distinguished pycnidia and non-septate pycnidiospores, followed by Bean Dextrose Agar medium (BDA) for number of produced pycnidia. Three concentrations (full strength, ½ and ¼ concs.) of V-8A, Cucumber Dextrose Agar (CDA) and Potato Dextrose Agar (PDA) were also tested, where ¼ conc. of V-8A and CDA produced pycnidia after 7 days only. Near Ultra Violet light boosted pycnidia production when compared with two other lightening systems. In case of incubation materials tested, Pyrex glass plates affected pycnidia production positively. Among several kinds of plant debris evaluated for pycnidia promotion, coriander debris was the best while debris of squash and cucumber, each alone, were the least. Moreover, plant debris affected the shape and number of pycnidia produced. Some bioagents promoted pycnidia production. Trichoderma harzianum was the best. The fungus started in producing pycnidia after the 4th day when the surface of mycelial culture was damaged, while no pycnidia were produced if wounding was made before media inoculation. | ||||
| Keywords | ||||
| Didymella bryoniae; gummy stem blight; pycnidia production and T. harzianum | ||||
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