Arbuscular mycorrhizal fungi decrease Meloidogyne enterolobii infection of Guava seedlings

Abstract

Guava (Psidium guajava L.) production is prominent in the irrigated fruit growing area of Brazil. However, the parasite Meloidogyne enterolobii (a phytonematode) has caused a decrease in guava production. Arbuscular mycorrhizal fungi (AMF) are known to be beneficial to plants; however, their ability to protect plants against nematodes such as M. enterolobii remains poorly known. This study aimed to monitor M. enterolobii infection in guava seedlings inoculated with three AMF species. After AMF inoculation, the seedlings were grown in sterile soil for 60 days before inoculation with 2000 M. enterolobii eggs. Plant growth parameters, mycorrhizal colonization and the number of Meloidogyne in the roots were determined over time (30 and 60 days after Meloidogyne inoculation). The AMF enhanced guava seedling growth, and reduced the amount of Meloidogyne in the roots at 30 and 60 days after nematode inoculation, indicating that these AMF species could serve as biocontrol agents of M. enterolobii in guava cultivation.

Roles of Arbuscular mycorrhizal Fungi as a Biocontrol Agent in the Control of Plant Diseases

“…Pre-inoculation of tobacco with G. mosy can significantly reduce the number of T. basicola and Meloidogyne incognita propagules and improve the disease resistance of plants to pathogenic nematodes [ 35 ]. AMF can parasitize cysts of soybean cyst nematodes and reduce various nematode diseases of oats, soybeans, cotton, cucumbers, tomatoes, kidney beans, alfalfa, citrus, and peach to varying degrees [ 36 , 37 ]. Shrinkhala et al [ 38 ] proposed that AMF symbionts can improve plant tolerance to nematodes but cannot fundamentally reduce nematode damage.…”

Arbuscular Mycorrhizal Fungi and Higher Plants

“…For example, AMF, G. mossae inoculation in the soybean plant results in the suppression of Pseudomonas syringae infection (Miransari 2011). Mycorrhizal fungi reduce varied nematocidal diseases of soybeans, cucumbers, cotton, alfalfa, peach, tomatoes, kidney beans, and citrus to various extents by parasitizing the cysts of nematodes (de Sá and Campos 2020;Rodrigues e Silva et al 2021). Whether symbiotic or pathogenic interactions, various fungi have developed diverse strategies to infect the host plants, where pathogen infection leads to plant death in most cases.…”

“…10.1). The mechanisms involved in reducing the quantity of Meloidogyne in plants associated with AMF range from competition for space and nutrients to the activation of plant defense mechanisms, with an increase in the number of genes involved in this process, as well as possible protective molecules (Sá and Campos 2020;Campos 2020;Ahamad et al 2023;Malviya et al 2023). However, studies regarding the biochemical, physiological, and genetic description of protection against Meloidogyne modulated by AMF are scarce; thus, there are still many gaps regarding this topic.…”

Combined treatment with Purpureocillum lilacinum MTL01 and Bacillus velezensis 83 reduces galling by Meloidogyne enterolobii and improves flowering in greenhouse-grown tomato

“…Traditional management of M. enterolobii in Mexico uses synthetic pesticides, but in trying to reduce their utilization, strategies based on crop rotation and biological control are currently analyzed (Lamberti, 1997;Tapia-Vázquez et al, 2022). For instance, arbuscular mycorrhizal fungi such as Acaulospora longulata (Campos et al, 2013;de Sá and Campos, 2020) and lamentous fungi such as Pochonia chlamydosporia (Silva et al, 2017), Paraboeremia taiwanensis (Liang et al, 2020), Trichoderma harzianum (Jindapunnapat et al, 2013) and Purpureocillium lilacinum stand out for their nematocidal capacity; as well as bacteria of the genus Pseudomonas, Paenibacillus (Sohrabi et al, 2018) and Bacillus sp. ( Consequently, there is a need for management schemes that enhance the e cacy of bioproducts.…”