MidnightWatcher – Prophecy in Motion

By Anna-Louise Taylor – “A banana and plantain fungus which has spread across the world originated in South East Asia, new research has found.

Black leaf streak disease (Mycosphaerella fijiensis) affects leaf photosynthesis, and causes premature ripening.

It also delays harvests and can affect banana quality, size and numbers.

A Molecular Ecology Journal study found ‘an original and unprecedented global scenario of invasion’.

It is the most important and destructive banana disease in the world, says one of the authors, Stephanie Robert.

‘It starts with small flecks and spreads to the whole banana leaves – the disease can totally destroy the whole banana plant,’ she says.

Using genetic markers, the team were able to map the streaks on 735 banana leaves from 37 different countries and identify genetic similarities.

‘The historical hypothesis was that it came from South East Asia,’ Ms Robert says.

Banana leaf with black leaf streak disease The fungus can cause bananas to ripen prematurely

While the fungus was first recorded in Fiji in 1963, it was initially thought that the centre of origin could have been Papua New Guinea or the Solomon Islands.

However, the study found the whole of South East Asia could be the centre of diversity – encompassing at least Malaysia, Philippines, Indonesia and Papua New Guinea…

Ms Robert says fungal spores cannot travel more than a few metres and are very sensitive to UV rays, but when travelling on the wind spores can be dispersed up to several hundred kilometres.

So this does not explain how the disease has travelled so far around the world, she says.” Read more.