Biofertilizer Application Enhances Drought Stress Tolerance and Alters the Antioxidant Enzymes in Medicinal Pumpkin (Cucurbita pepo convar. pepo var. Styriaca)

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Najafi S., Nazari Nasi H., Tunçtürk R., Tunçtürk M., Z. Sayyed R., Amirnia R.

Horticulturae, vol.7, no.588, pp.1-11, 2021 (SCI-Expanded)

  • Publication Type: Article / Article
  • Volume: 7 Issue: 588
  • Publication Date: 2021
  • Doi Number: 10.3390/horticulturae7120588
  • Journal Name: Horticulturae
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1-11
  • Van Yüzüncü Yıl University Affiliated: Yes


Abstract: The effects of mycorrhiza, Thiobacillus and Nitroxin (Azotobacter and Azospirillum sp.)

biofertilizers under drought stress conditions with four levels of field capacity (FC) (control(100%),

85%, 70%, and 50%) on the antioxidant enzyme activities of medicinal pumpkin (Cucurbita pepo

convar. pepo var. Styriaca) were evaluated during the years 2018–2019. Irrigation levels exhibited

significant effects on all studied variables, except for the catalase (CAT) enzyme. A significant

correlation was observed between the effects of irrigation levels and biofertilizers on antioxidant

enzymes, soluble protein content, and grain yield. The highest activity of catalase and ascorbate

peroxidase (APX) enzymes was achieved using mycorrhiza in 50% FC. Increasing drought intensity

and mycorrhiza stimulated glutathione reductase (GR) and guaiacol peroxidase (GPX) activities

by 32% and 66%, while Nitroxin increased them by 16% and 43%, respectively. Under severe

drought stress conditions, only mycorrhiza exhibited a positive effect on GR and GPX enzymes.

Under moderate and severe drought stress conditions, Nitroxin increased grain yield by 13% and

12.6%, respectively. The irrigation regimes and bio-fertilizers had a significant effect on -sitosterol

percentage. The highest amount was observed at the highest level of drought stress. Among the

various bio-fertilizers treatments, the application of Thiobacillus yielded the highest percentage of

-sitosterol. The results of the present study demonstrate that the application of biofertilizers is

beneficial in coping with drought stress.