Yield, quality and shelf-life problems in lettuce due to virus infections in the UK

在英国，集约化农业和连续种植莴苣作物意味着莴苣在整个季节（3月至10月）都在同一块地里种植。这使它们容易受到植物疾病的侵害，并导致病原体，特别是病毒的积累。在英国，人们对哪些病毒感染生菜、这些病毒的发病率以及它们对生菜质量和产量的影响知之甚少。2015年，英国生菜出现了严重的病毒问题，导致1400万莴苣头因病毒感染而损失。在英国，生菜主要种植在户外，根据季节的不同，生菜的成熟期可能需要6-10周。新烟碱类杀虫剂的丧失导致作物中昆虫病毒媒介，特别是蚜虫的增加。由于某些病毒寄主范围很广，导致邻近的杂草物种和有益的传粉者田缘成为寄主，这加剧了这种情况。我们在2021年的初步数据中发现了剑桥郡一种作物中的两种病毒。芜菁黄病毒（TuYV）被发现感染生菜和邻近的杂草品种。采用酶联免疫吸附试验（ELISA）检测TuYV感染，RT-PCR和测序证实。TuYV是迄今为止检测到的最常见的病毒，已知对蔬菜芸苔的质量、发育、产量（最多减少65%）和储存性有重大影响，据报道，在油菜（OSR）和蔬菜芸苔作物中，TuYV的发病率高达100%，为病毒提供了一个储存库。除了TuYV，近年来在英国莴苣作物中可靠和最终鉴定的其他病毒是2015年的黄瓜花叶病毒（CMV）和生菜花叶病毒（LMV，这是一种种子传播的病毒）。

Intensive farming and sequential plantings of lettuce crops in the UK mean lettuce is grown in the same fields for the whole season (March-October). This makes them vulnerable to plant diseases and results in a build-up of pathogens, particularly viruses. Very little is known about which viruses are infecting lettuce in the UK, the incidence of these viruses and their impact on lettuce quality and yield. In 2015 there was a major virus problem in lettuce in the UK resulting in the loss of 14 million lettuce heads that were ploughed in due to virus infection. Lettuce is predominantly grown outdoors in the UK and plant maturity can take between 6-10 weeks depending on the time of the season. The loss of neonicotinoid insecticides has resulted in the increase of insect virus vectors in crops, particularly aphids. This is exacerbated by some viruses having very wide host ranges resulting in adjacent weed species and beneficial pollinator field margins serving as reservoirs. Our preliminary data from the 2021 season identified two viruses within a crop in Cambridgeshire. Turnip yellows virus (TuYV) was found infecting both lettuce and adjacent weed species. TuYV infection was detected by enzyme-linked immunosorbent assay (ELISA) and confirmed by RT-PCR and sequencing. TuYV was by far the most frequent virus detected and is known to have a significant effect on the quality, development, yield (up to 65% reduction) and storability of vegetable brassicas and incidences of up to 100% have been reported for TuYV in oilseed rape (OSR) and vegetable brassica crops, providing a reservoir of the virus. Other than TuYV, the only other viruses that have been reliably and conclusively identified in lettuce crops in the UK in recent years are cucumber mosaic virus (CMV) and lettuce mosaic virus (LMV, which is seed-borne) in 2015.