Fears that almost all of Britain’s ash trees face annihilation may be exaggerated, according to a comprehensive genetic¹ analysis of ash across the UK and Europe.

根据在英国和欧洲大陆对白蜡树(ash tree)进行的全面遗传分析，有关英国几乎所有白蜡树都面临灭绝的担心可能被夸大了。

The study, carried out by a collaboration² of 12 academic research teams and published in Nature, found that British trees are more likely than their continental³ counterparts to carry genes⁴ that protect against ash dieback, a fungal infection with the potential to wipe out 90 per cent of the European ash population.

这项研究由12个学术研究团队协同开展，结果发表于《自然》(Nature)杂志。研究发现，相比欧洲大陆的白蜡树，英国的白蜡树更有可能携带抵御白蜡树枯梢病(ash dieback)的基因；这是一种真菌感染，有可能杀死90%的欧洲白蜡树种群。

“It’s an encouraging hint⁵ that things may not be as bad as we had feared,” said study leader Richard Buggs of Queen Mary University of London and Royal Botanic Gardens Kew.

“这是一个令人鼓舞的消息，表明事情可能不像我们此前担心的那样糟糕，”伦敦大学玛丽皇后学院(Queen Mary University of London)和皇家植物园邱园(Royal Botanic Gardens Kew)的研究带头人理查德.巴格斯(Richard Buggs)表示。

“But these are preliminary indications and I wouldn’t want to see government policy on ash dieback shaped by the research until we have more evidence for the susceptibility of British trees.”

“但这些都是初步迹象，在我们有更多证据表明英国白蜡树的易感性之前，我不想看到针对白蜡树枯梢病的政府政策受到此项研究的影响。”

The encouraging news comes from the discovery of a link between reduced susceptibility to ash dieback and lower levels of plant chemicals called iridoid glycosides. Most British ash trees produce less of these compounds than continental ones, the genetic analysis suggests.

这一令人鼓舞的消息源于这样一个发现：较低的白蜡树枯梢病易感性与较低水平的植物化学物质“环烯醚萜苷类”(iridoid glycosides)之间存在关联。遗传分析似乎表明，相比欧洲大陆的白蜡树，多数英国白蜡树生成的这类化合物较少。

Mr Buggs said the findings might explain why ash dieback has not spread as rapidly in the UK as feared in 2012 when the fungus⁶ first arrived from continental Europe. “Most of our early models were based on the Danish experience,” he said.

巴格斯表示，这些研究结果可能解释了为什么2012年白蜡树枯梢病从欧洲大陆传播至英国时，没有像人们担心的那样快速传播。“我们使用的多数初期模型都是基于丹麦的经验，”他说。

The disease causes trees to lose their leaves and eventually die. It has killed millions of plants in eastern and northern Europe since reaching Poland in 1992. Young trees die fast while mature ash often take several years to succumb⁷.

这种疾病会导致白蜡树落叶，最终枯萎而死。自1992年传播至波兰以来，它已在东欧和北欧杀死了数以百万计的白蜡树。幼树很快死亡，而成年白蜡树往往在几年后死亡。

“Plants use a vast range of chemicals to defend against fungal attack, and the primary objective [of the project] was to identify differences which could be used to screen young ash trees and choose the best ones for replanting,” said co-author Murray Grant of the University of Warwick. “Our findings underline the need for further research to ensure that we select ash trees resilient to present and future threats.”

“植物利用多种多样的化学物质来抵御真菌侵袭，（该项目的）主要目标是识别差异，以便筛选幼树，挑选出最佳的树进行补种，”研究报告联名作者、华威大学(University of Warwick)的默里.格兰特(Murray Grant)表示。“我们的研究结果突显了进一步研究的需要，以确保我们筛选出对当前乃至未来的威胁具有抵抗力的白蜡树。”

While the genetic analysis is encouraging news for the fungal resistance of British ash, it may have a downside, too. Iridoid glycosides help to protect plants against insect pests, so low levels could make the British trees more vulnerable to the other big threat to European ash, a beetle⁸ called the emerald ash borer.

虽然遗传分析在英国白蜡树的真菌抗性上带来了令人鼓舞的消息，但它也可能意味着一个弱点。环烯醚萜苷类有助于保护植物免受虫害，因此这类化合物的含量较低可能使英国白蜡树在另一大威胁——一种被称为白蜡窄吉丁(emerald ash borer)的甲虫——面前更为脆弱。

The beetle has devastated⁹ vast tracts¹⁰ of ash in North America and is spreading westward¹¹ from Russia into Europe. Although emerald ash borer has not reached the UK, arboriculturists fear its arrival is just a matter of time.

这种甲虫在北美摧毁了大量白蜡树，并正从俄罗斯向西扩散，直扑欧洲。虽然白蜡窄吉丁尚未抵达英国，但树木栽培者担心，它们的到来只是一个时间问题。