Many tomato growers are familiar with the scourge of bacterial canker – the wilted leaves and blistered fruit that can spoil an entire season’s planting. For those whose livelihoods depend on tomatoes, this pathogen — Clavibacter michiganensis — is economically devastating.
In a new paper, Cornell University researchers showed that wild tomato varieties are less affected by bacterial canker than traditionally cultivated varieties.
The team wanted to understand how bacteria spread and colonize in wild tomatoes versus cultivated ones. They zeroed in on the plants’ vascular systems — specifically their xylem vessels.
Like individual veins in a human, xylem vessels transport water and nutrients from soil throughout the plant. The team found that in cultivated species, bacterial canker spreads everywhere, while in wild species the bacteria remain confined to certain xylem vessels without moving much into surrounding tissues.
This is the first study confirming that wild tomatoes are susceptible to bacterial canker, though the infection is less severe than in cultivated varieties. But while a severe infection causes fewer symptoms in the wild plant, it can still cause lesions on the fruit.
The paper published in the journal Phytopathology.
Co-authors were Christine Smart, professor of plant pathology and plant-microbe biology in the College of Agriculture and Life Sciences; F. Christopher Peritore-Galve, a doctoral student in the Smart Lab; and Christine Miller, a 2018 Smart Lab undergraduate summer intern from North Carolina State University.
This work was supported by funding from the USDA National Institute of Food and Agriculture.
