Abstract
The ecosystem is considerably affected due to the extensive use of chemical pesticides and fertilizers. As an alternative strategy, this study aimed to assess the biocontrol potential of the bioagents arbuscular mycorrhizal fungi and plant growth-promoting Trichoderma harzianum MZ025966 against tomato root-knot nematodes (Meloidogyne javanica). T. harzianum showed a great potentiality to produce indole acetic acid (IAA) (12.11 ± 2.12 μg/mL) and exhibited a noticeable activity of ammonification. Furthermore, T. harzianum revealed protease and lipase enzymatic activity of 28.36 ± 2.82 U/mL and 12.30 ± 0.31 U/mL, respectively, which may illustrate the control mechanism of nematode eggs and juveniles. As in mycorrhizal and/or T. harzianum inoculated tomato plants, the penetration rates of nematodes, as well as the number of juveniles, females, egg mass, and galls were significantly reduced. The lowest number of juveniles was observed in the case of either single mycorrhizal inoculation (45%) or in combination with T. harzianum (55%). The enzymatic activity of glutathione peroxidase and catalase was enhanced in tomato plants inoculated with the bioagents to overcome the negative impact of nematode parasitism. Our results proved that the application of biocontrol agents not only reduced the nematode population and penetration rate but also improved the plant growth, increased the nutritional elemental content and stimulated the plant’s systematic resistance.
Highlights
Nematodes, or roundworms, the most abundant animals in the world, constitute the phylum Nematoda
The results exhibited that in the liquid medium, the protease and lipase activity produced by T. harzianum were 28.36 ± 2.82 and 12.30 ± 0.31 U/mL, respectively
Whereas the protease and lipase specific activities retained by T. harzianum were estimated to be 20.40 ± 5.35 and 9.50 ± 1.45 U/mg protein, respectively (Table 1)
Summary
Roundworms, the most abundant animals in the world, constitute the phylum Nematoda. Nematodes occur as parasites in plants, animals, or as free-living forms in different habitats (marine environment, freshwater, and soils). Root-knot nematodes (genus Meloidogyne) (RKN) are endoparasites of roots and have been assessed to cause around USD 173 billion of annual damages to crops planted worldwide [1]. Nematode larvae infect the plant root system and develop root-knot galls that exhaust the plant’s nutrients and photosynthate. Nematodes are likely to be undervalued, because farmers are often oblivious of their presence because the plant symptoms caused by nematode infection are oftentimes non-specific, so it is difficult to attribute losses in crop to nematode infection [3]. Further losses might be correlated to the quality of food and morphological imperfections associated with nematode infection symptoms [4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
