نوع مقاله : مقاله پژوهشی
نویسندگان
1 بخش کنترل بیولوژیک، موسسه تحقیقات گیاهپزشکی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران
2 گروه کشاورزی، پژوهشکده گیاهان و مواد اولیه دارویی، دانشگاه شهید بهشتی، اوین، تهران، ایران
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Cucumber powdery mildew (Podosphaera xanthii), as one of the most destructive threats to cucumber, has challenged chemical control due to the emergence of fungal resistance. Biological control agents serve as an environmentally friendly alternative and are effective in disease suppression through various mechanisms, including the enhancement of phenolic compound production. Two biocontrol formulations Bacillus subtilis B2 and Trichoderma harzianum K18, and the fungicide Domark, reduced disease severity in the greenhouse to 30.84%, 39.16%, and 31.49%, respectively.
The biochemical assessment of phenolic compounds through spectrophotometric techniques and high-performance liquid chromatography (HPLC) revealed notable variations among treatments: The total phenol content in healthy control plants ranged from 30.33 to 37.7 mg per 100 g of dry weight and increased by 103.7% after 48 hours post- infection, while reaching 159.12%, 129.18%, and 142.98% in the B2, K18, and Domark treatments, respectively. Additionally, total flavonoids exhibited increases of 373.5% and 389.2% due to the effects of B2 and K18, respectively.
The HPLC analysis identified seven phenolic compounds. Caffeic acid, which had a baseline concentration of 23 mg/100g DW, demonstrated a significant increase of 154% under K18 treatment. Additionally, ferulic acid (205%), rutin (103%), and rosmarinic acid (145%) displayed the most substantial increases when K18 was present. Moreover, rutin exhibited a negative correlation with disease severity.
It seems the deliberate induction of phenolic compounds, such as caffeic acid and rutin – likely accomplished through the activation of resistance pathways and the induction of defense gene expression – proves to be effective in suppressing disease.
کلیدواژه‌ها [English]
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