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

在英国，集约化耕作和生菜作物的连续种植意味着生菜在整个季节(3-10月)都在相同的田地里种植。这使得它们容易受到植物疾病的影响，并导致病原体的积累，特别是病毒。在英国，人们对哪些病毒正在侵染生菜、这些病毒的发病率以及它们对生菜品质和产量的影响知之甚少。2015年，英国的生菜出现了严重的病毒问题，导致1400万个生菜因感染病毒而被犁入土中。在英国，生菜主要在户外种植，根据季节的不同，植物成熟期可能需要6-10周。新烟碱类杀虫剂的损失导致了农作物中昆虫病毒媒介的增加，特别是蚜虫。一些病毒具有非常广泛的寄主范围，导致邻近的杂草物种和有益的传粉者田野边缘成为储藏者，这加剧了这种情况。我们来自2021年季节的初步数据在剑桥郡的一种作物中发现了两种病毒。芜菁黄化病毒(TuYV)侵染生菜及邻近杂草。用酶联免疫吸附试验(ELISA)检测TuYV感染，RT-PCR和测序证实感染。TuYV是迄今为止检测到的最常见的病毒，已知对蔬菜甘蓝的质量、发育、产量(减产高达65%)和耐贮性有重大影响，据报道，在油菜(OSR)和蔬菜甘蓝作物中，TuYV的发病率高达100%，为病毒提供了宿主。除TuYV病毒外，近年来在英国生菜作物中唯一可靠和确定的病毒是2015年在生菜作物中发现的黄瓜花叶病毒(CMV)和生菜花叶病毒(LMV，种子传播)。

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.