Throwing apple cores out of the car window risks obliterating Britain’s wild fruit trees, scientists warn
- Experts studied wild species along the verges of the A9 and M9 in Scotland
- They found many trees were non-native and had sprouted from discarded seeds
- They say these cultivated species become cross-pollinated with wild apples
Throwing an apple core from your car window may seem harmless enough – but it’s threatening the future of native species, scientist are warning.
Experts studying wild species along the verges of the A9 and M9 in Scotland were surprised to find that many trees were non-native – and had sprouted from the seeds of discarded supermarket apples.
They say these cultivated species become cross-pollinated with wild apples – also known as crab apples – to create hybrids which could eventually see the wild apple tree die out.
Dr Markus Rahsum, a molecular biologist at the Royal Botanic Gardens Edinburgh who carried out a groundbreaking study on wild apples, said: ‘I wouldn’t want to discourage people from planting apple trees in their gardens.
Throwing an apple core from your car window may seem harmless enough – but it’s threatening the future of native species, scientist are warning (file image)
‘What I would like to discourage is people randomly planting apple trees in the wild. We want to keep wild apples wild. Another thing is not chucking your apple core out of the window. I’m guilty of it as well.
‘But when I was looking for apple trees I suddenly realised how many there are growing along motorways and busy roads. These apple trees are starting to sprout across busy motorways, along the M9 and the A9. And they are all cultivated apples.’
Dr Rahsum carried out a survey of the genetic make-up of apple trees growing in the wild in Scotland and discovered that half of those in the central belt are hybrids.
But now an orchard of 120 pure-bred wild apples – or malus sylvestris – is being created in a bid to help secure the future of the fruit.
Experts say cultivated species become cross-pollinated with wild apples – also known as crab apples – to create hybrids which could eventually see the wild apple tree die out (file image)
The trees have been DNA tested to ensure their purity, and a genetic screening programme will also be carried out next year at nurseries selling wild apple trees to establish how pure they are.
Dr Rahsum said: ‘Cultivated apples have been grown in orchards since at least 1100, and probably longer, so there has been a long period over which crossing between wild and cultivated forms could take place.
‘The particularly large numbers of hybrids found in lowland areas suggest that these forms have found their way into the nursery trade and since been widely planted.’
Experts have also urged people not to discard apple cores or to plant crab apple trees, which might have no wild genes, out in the countryside.
The southern Highlands and Dumfries and Galloway have higher percentages of pure wild apples – 85% and 75% respectively – as they are less populated.