Relationships between M. enterolobii and F. solani: spatial and temporal dynamics in the occurrence of guava decline

Abstract

Guava decline, caused by the interaction between the phytonematode Meloidogyne enterolobii and the fungus Fusarium solani, has caused direct and indirect losses to the whole productive chain of guava. Aiming to understand the interaction mechanisms between M. enterolobii and F. solani, this study carried out a bioassay on guava plants with roots in two different treatments: inoculated separatelyor together with the fungus and/or nematode. The nematode parasitism not triggered an systemic effect on the plant become susceptible to root rot caused by the fungus.Therefore, it was concluded that there was a local effect of parasitism by M. enterolobii on the pathogenicity of F. solani in guava roots, making it necessary for the two pathogens to occupy the same space at the same time for occurrence of guava decline.Keywords: complex disease, Fusarium solani, guava root-knot nematode, Meloidogyne enterolobii, Psidium guajava. Cite asGomes VM, Souza RM, Almeida AM, Dolinski C. Relationships between M. enterolobii and F. solani: spatial and temporal dynamics in the occurrence of guava decline. Nematoda. 2014;1:e01014. http://dx

Genetic structuring of segregating populations of Psidium spp resistant to the southern root-knot nematode by Bayesian approach as basis for the guava breeding program

“…Genetic diversity is essential to sustain the productivity of a crop, since it provides 'new genes' for yield, adaptation, and disease resistance. The disease known as 'guava decline' has caused a strong economic impact for the guava crop, with losses estimated at over 90 million dollars (Gomes et al 2014). Therefore, identifying resistant genotypes is a measure of paramount importance to increase yields.…”

“…enterolobii, responsible for the appearance of galls in large quantities and yellowing of the leaf edges, ultimately leading to total defoliation of the shoots (Gomes et al 2014). A matter of an even greater concern is the synergistic association between M. enterolobii and the fungus Fusarium solani, since root rots occur only when two pathogens are involved in the process.…”

“…This disease in association is known as the 'guava decline', which eradicates numerous orchards of this fruit (Gomes et al 2011). This result in huge economic impacts for producers, once the losses are estimated to reach over $ 70 million (Gomes et al 2014).…”

Meloidogyne enterolobii risk to agriculture, its present status and future prospective for management

“…Above-ground symptoms include leaf yellowing, wilting, and stunted growth while below-ground symptoms, such as root galls, can be considerable in size and quantity ( Jia et al., 2022 ). Plants infected by M. enterolobii are more vulnerable to secondary plant infections, such as Fusarium solani parasitizing guava after infestation ( Gomes et al., 2014 ).…”

Selection of interspecific <i>Psidium</i> spp. hybrids resistant to <i>Meloidogyne enterolobii

“…First detected in 2001, this disease has decimated commercial orchards, where the guava plants parasitized by the nematode Meloidogyne enterolobii become susceptible to the root rot caused by the Fusarium solani complex, constituting the main disease affecting the guava crop (Gomes, Souza, Midorikawa, Miller, & Almeida, 2012;Gomes, Souza, Almeida, & Dolinski, 2014). The parasitism of the phytonematode Meloidogyne enterolobii predisposes guava plants immune to Fusarium solani to extensive degradation of the roots caused by this fungus, which leads to nutritional deficiencies, chlorosis, burn of the leafedges, leaf fall, drastic decline in yield, and plant death, in an irreversible process that takes only a few months (Gomes, Souza, Silva, & Dolinski, 2008;Gomes et al, 2014;Gomes et al, 2017). This leads to considerable economic losses to farmers; in 2009, losses were estimated at over US$ 70,000 (Pereira, Souza, Souza, Dolinski, & Santos, 2009).…”