LetgenPro|Multiplex Real Time PCR Kit 100 rxn (Gummosis) (Phytophthora spp./ Xanthomonas axonopodis)

Trunk diseases and vascular infections represent a critical threat to perennial crops, often resulting in systemic decline and orchard-wide productivity loss. The Letgen Biotech Multiplex RT-qPCR assay utilizes a targeted molecular approach for the simultaneous detection and differentiation of two primary agents of gummosis: the oomycete Phytophthora spp. and the bacterium Xanthomonas axonopodis. 

The epidemiology of these pathogens is driven by high moisture and structural tissue vulnerability. Phytophthora spp. thrive in water-saturated soils, where motile zoospores initiate crown rot and trunk infections. Conversely, Xanthomonas axonopodis is a highly contagious bacterial pathogen dispersed by wind-driven rain and mechanical pruning, invading the host through natural openings or wounds. Both pathogens can lead to the characteristic oozing of sap (gum) as the host tissue degrades under infection. 

Phytophthora spp. are the principal agents of Phytophthora Gummosis. They destroy the cambium and bark tissues at the base of the tree, obstructing nutrient flow and leading to “foot rot.” The infection manifests as dark, water-soaked lesions that eventually ooze a sticky, amber-colored gum. 

Xanthomonas axonopodis is a causal agent of bacterial canker, with gummosis occurring as a secondary host response to tissue necrosis. In addition to necrotic fruit and leaf spots, it induces deep woody cankers. These infections disrupt the plant’s internal pressure, resulting in gummosis and providing a persistent reservoir for bacterial inoculum within the orchard 

Because these pathogens produce overlapping symptoms, visual diagnosis is often insufficient for distinguishing between a water mold and a bacterial infection. The Multiplex assay enables the identification of pathogen-specific DNA in a single reaction, providing a streamlined diagnostic workflow. This molecular approach supports informed disease management, allowing growers to choose the correct intervention before systemic damage compromises the plantation’s longevity.