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P a g e
Reading Test 5
SECTION 1
Going Bananas
A
The world's favourite fruit could disappear forever in 10 years’ time. The banana is
among the world’s oldest crops. Agricultural scientists believe that the first edible banana
was discovered around ten thousand years ago. It has been at an evolutionary standstill
ever since it was first propagated in the jungles of South-East Asia at the end of the last
ice age. Normally the wild banana, a giant jungle herb called Musa acuminata, contains
a mass of hard seeds that make the fruit virtually inedible. But now and then,
hunter-
gatherers must have discovered rare mutant plants that produced seed-less, edible fruits.
Geneticists now know that the vast majority of these soft-fruited plants resulted from
genetic accidents that gave their cells three copies of each chromosome instead of the
usual two. This imbalance prevents seeds and pollen from developing normally, rendering
the mutant plants sterile. And that is why some scientists believe the world's most popular
fruit could be doomed. It lacks the genetic diversity to fight off pests and diseases that are
invading the banana plantations of Central America and the small-holdings of Africa and
Asia alike.
B
In some ways, the banana today resembles the potato before
blight brought famine to
Ireland a century and a half ago. But "it holds a lesson for other crops, too", says Emile
Frison, top banana at the International Network for the Improvement of Banana and
Plantain in Montpellier, France. "The state of the banana,,
,
Frison warns, "can teach a
broader lesson the increasing standardisation of food crops round the world is threatening
their ability to adapt and survive."
C
The first Stone Age plant breeders cultivated these sterile freaks by replanting cuttings
from their stems. And the descendants of those original cuttings
are the bananas we still
eat today. Each is a virtual clone, almost devoid of genetic diversity. And that uniformity
makes it ripe for disease like no other crop on Earth. Traditional varieties of sexually