O trecho do terceiro parágrafo “An aphid-resistant wheat
crop could have huge benefits for farmers and the
environment because the plants would no longer need to
be sprayed with insecticides.”
GM wheat no more
pest-resistant than ordinary crops, trial shows
GM wheat designed to repel aphids is no more effective at repelling
the bugs than standard varieties a major field trial has revealed
Ian Sample
June 25, 2015
A major field trial of GM wheat that is designed to
repel aphids (small insects) has found the crop is no better
protected against the pests than conventional wheat. The
results come from two years of trials that compared aphid
attacks on standard wheat plants with those suffered by a
GM version modified to release a natural aphid repellent.
Scientists created the GM wheat strain in the hope
that it would deter aphids, which devour the crops and can
leave them with infections. They modified the wheat to
produce a natural pheromone which aphids release when
under attack from predators. The “aphid alarm” makes
the bugs flee to safety. Aphids are not the only organisms
that release the odour though. More than 400 plants have
evolved to secrete the same substance, called E-betafarnesene,
or EBF, including peppermint. The chemical
doubles up as an attractant for some insects that kill
aphids, such as parasitic wasps.
Prior to the field trial, lab tests at Rothamsted found
that the pheromone worked as a highly-effective aphid
repellent. The work bolstered researchers’ hopes that
the trial would demonstrate the crop’s resilience against
aphids in the wild. An aphid-resistant wheat crop could
have huge benefits for farmers and the environment
because the plants would no longer need to be sprayed
with insecticides.
“The disappointing thing is that when we tested it in
the field, we didn’t find any significant reduction in aphid
settlement in the test plots,” said Toby Bruce, who worked
on the trial. Details of the trial are published in the journal
Scientific Reports.
(www.theguardian.com. Adaptado.)
GM wheat no more
pest-resistant than ordinary crops, trial shows
GM wheat designed to repel aphids is no more effective at repelling the bugs than standard varieties a major field trial has revealed
Ian Sample
June 25, 2015
A major field trial of GM wheat that is designed to repel aphids (small insects) has found the crop is no better protected against the pests than conventional wheat. The results come from two years of trials that compared aphid attacks on standard wheat plants with those suffered by a GM version modified to release a natural aphid repellent.
Scientists created the GM wheat strain in the hope that it would deter aphids, which devour the crops and can leave them with infections. They modified the wheat to produce a natural pheromone which aphids release when under attack from predators. The “aphid alarm” makes the bugs flee to safety. Aphids are not the only organisms that release the odour though. More than 400 plants have evolved to secrete the same substance, called E-betafarnesene, or EBF, including peppermint. The chemical doubles up as an attractant for some insects that kill aphids, such as parasitic wasps.
Prior to the field trial, lab tests at Rothamsted found that the pheromone worked as a highly-effective aphid repellent. The work bolstered researchers’ hopes that the trial would demonstrate the crop’s resilience against aphids in the wild. An aphid-resistant wheat crop could have huge benefits for farmers and the environment because the plants would no longer need to be sprayed with insecticides.
“The disappointing thing is that when we tested it in the field, we didn’t find any significant reduction in aphid settlement in the test plots,” said Toby Bruce, who worked on the trial. Details of the trial are published in the journal Scientific Reports.
(www.theguardian.com. Adaptado.)
Gabarito comentado
O trecho do terceiro parágrafo mostra as vantagens esperadas do trigo GM resistente aos afídeos.
Alternativa A
