Damola Adejoro. Image courtesy Lincoln University

Why do some grapevines succumb to trunk disease while others right next to them seem to escape it, though they are all genetically identical?

A new study* co-authored by Lincoln University researchers has identified beneficial microorganisms in the trunks of the seemingly immune plants as a factor.

Co-author and Lincoln PhD student, Damola Adejoro, said the research had involved more than 10 vineyards around the country and samples were taken from escape vines, or vines without disease symptoms despite being around diseased vines.

The microorganisms in their stems were compared to those of the plants that had fallen victim to Grapevine Trunk Disease (GTD).

Damola said before this investigation, reports of GTD escape were primarily based on anecdotal evidence.

“However, we showed that the fungal and bacterial microbiomes of GTD escape vines significantly differed from those of the diseased vines.”

This suggested the microbial community of grapevines played a critical role.

GTD causes significant yield losses, can negatively impact vineyard productivity, and can ultimately lead to vine death.

Damola said Sauvignon Blanc, which makes up the bulk of New Zealand’s wine exports, was susceptible to the disease, especially after pruning.

He added that there were currently no approved fungicides for controlling GTDs, and this had contributed to the exploration of alternative approaches.

The research could lead to the development of a probiotic of the beneficial microorganisms in the escape plants, which could be administered to the vines to help protect them.

*Grapevines escaping trunk diseases in New Zealand vineyards have a distinct microbiome structure https://www.frontiersin.org/articles/10.3389/fmicb.2023.1231832/full

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