Synergistic Effect of Bioagents and Antioxidants Against Root-Knot Nematode, Meloidogyne incognita on Sunflower

D. Ibrahim,H. Metwaly,Atef El-Sagheer

doi:10.21608/ejaj.2021.187532

Abstract

Root-knot nematodes are globally considered one of the most common phytonematodes infecting sunflower crops. In this context, current study, treatments were designed to enhancing the effect of biological control against Meloidogyne incognita by Trichoderma harzianum and Bacillus subtilis alone or in combination with antioxidant; ascorbic and salicylic acids. All treatments significantly suppressed root-knot nematode compared to control. Generally, the results indicated that the treatments of mixtures of antioxidants + bioagents showed a better response in suppression of root-knot nematode than the bioagents alone, as mixture of T. harzianum + B. subtilis gave the highest reduction in nematode population (72.3% and 80.0%).While the best synergistic effect was noticed by combination between T. harzianum and salicylic acid (74.9% and 84.9%) during the growing seasons 2018 and 2019,respectively.This positively reflected on the plant health through induction of defense related components (phenolic content and oxidative enzymes).

Highlights

Sunflower, Helianthus annuus L. is considered one of the oilseed crops, It was ranked third as an oil crop globally produced (Pilorge, 2020 and Khan et al, 2015)
In Egypt, root-knot nematode, Meloidogyne incognita (Kofoid and White,1919) Chitwood, 1949 is the most deleterious phytonematodes contributing to stunting, wilting, poor plant growth and significant yield losses (Ibrahim and Mokbel, 2009; ElSagheer,2019).Bio-control of soil borne pathogens as phytonematodes by antagonistic microorganisms has been regarded as a more acceptable alternative to existing chemical methods to decrease the populations of phytonematodes (Askary and Martinelli, 2015)
In addition to the beneficial effects on the crop yield, B. subtilis was able to control M. incognita in vegetable crops through a wide spectrum of effects that bacterium has in suppressing plant nematodes and was mentioned in previous studies (Araujo, 2008; de Araújo et al, 2011; Higaki and Araujo, 2012; Vlamakis et al, 2013; Rao et al, 2014) which nominated it as one of the most important control factors that its effects must be expanded in the suppression of plant nematodes (Bettiol and Morandi, 2009)

Summary

Introduction

Helianthus annuus L. is considered one of the oilseed crops, It was ranked third as an oil crop globally produced (Pilorge, 2020 and Khan et al, 2015). Among the promising bacteria as a bio-agent to control of soil pathogens, Bacillus subtilis represents one of the most studied (Bettiol and Morandi, 2009).This bacterium is local natural in soil in Egypt (Abd-Elsalam and El-Hanafy, 2009), produces enzymes, plant hormones and antibiotics which provide benefits to plants, and improve their growth (Silveira, 2001). In addition to the beneficial effects on the crop yield, B. subtilis was able to control M. incognita in vegetable crops through a wide spectrum of effects that bacterium has in suppressing plant nematodes and was mentioned in previous studies (Araujo, 2008; de Araújo et al, 2011; Higaki and Araujo, 2012; Vlamakis et al, 2013; Rao et al, 2014) which nominated it as one of the most important control factors that its effects must be expanded in the suppression of plant nematodes (Bettiol and Morandi, 2009)

Methods

Results

Conclusion