DNA technology helps farmers identify crop diseases DNA技术帮助农民识别庄稼疾病

陈维维

庄稼染上病害是再司空见惯不过的事情了，农民们为消灭病害付出了很多的努力，但大多都无济于事。随着现代科学技术的发展，一家英国科技公司发明了一台识别DNA的新農用设备。在发现病害时，这台设备能够及时改善物种特性，让农民们不再忍受庄稼疾病带来的困扰。

It is often difficult for farmers to identify diseases quickly enough to protect their crops. Now， some farmers are using a simple device directly in the field to find viruses before they spread.

In Tanzania， several viruses are a threat to cassava （木薯） crops. Farmers struggle to identify the diseases in an urgent effort to avoid severe crop damage. If they do not know what is attacking their crops， they cannot decide the best way to fight the disease.

A device from British technology company Oxford Nanopore is changing that. The device extracts （提取） DNA from plants and helps farmers identify what is harming their crops so they can change to more resistant crops.

Laura Boykin， who works with the Cassava Virus Action Project， brought the device to a Tanzanian farm owned by Asha Mohamed. “We are here collecting leaf punches from infected material to test， to do a DNA extraction and then start sequencing （排序） in the field.”

The testing identified a number of viruses in the cassava fields near Mohameds farm. The process also discovered that plants con?sidered resistant to disease had a very low viral （病毒性的） level. Once the viruses were identified， Asha Mohamed was given two kinds of seeds that are resistant to the diseases.

In another case， DNA was collected from a pawpaw（木瓜） tree farm in Kenya. With that test， the technology was able to identify diseases affecting Naomi Mumos crops. “All my pawpaws were affected by a disease， and I didnt know what kind of disease it was. But now， I have people who have identified the disease using new technology within a very short time.”

Laura Boykin and other researchers returned to Mohameds cassava farm nine months later. She said the new plants were very healthy and had produced a large， successful crop. “After nine months of her growing the improved varieties， we are back here， and today we harvested her cassava plants and she went from zero yield to 35 tons per hectare， which is massive.”

The speed at which farmers identify diseases can mean the difference between the success and failure on large areas of crop land. Now， the use of such simple and easily transportable DNA sequencing devices is making that possible.

[Reading][Check]]

1.How does the device help to recognize crop diseases？

A.By checking the related viruses. B.By taking out DNA from plants.

C.By collecting the soil in the field. D.By researching the infected crops.

2.Which word can best describe Naomi Mumos attitude to the new technology？

A.Shocked.B.Puzzled.C.Satisfied.D.Skeptical.

3.What can we infer from what Laura Boykin said in paragraph 7？

A.Mohamed has made a big fortune by planting cassava.

B.Mohamed has benefited little from the new technology.

C.Mohamed has grown varieties of new plants in her field.

D.Mohamed has changed her life in less than nine months.

[Language][Study]

Ⅰ.Important vocabulary in the text

1.identify v. 確认;识别

2.device n. 设备

3.urgent adj. 紧急的

4.severe adj. 严重的

5.resistant adj. 有抵抗力的

6.process n. 过程

7.transportable adj. 可运输的

Ⅱ.Sentence for writing

如果他们不知道是什么攻击了他们的庄稼，他们就不能决定抗击疾病的最好办法。

If they do not know           is attacking their crops， they cannot decide the best way            （fight） the disease.

【点石成金】第一空应填入what，what引导宾语从句，且在从句中作主语;第二空应填入to fight，当名词为way、ability、chance等抽象名词时，通常用动词不定式作定语。