Exploiting pathogenomics and resistance for control of Fusarium wilt of lettuce

莴苣枯萎病是由土传真菌尖镰孢莴苣专化型（Fusarium oxysporum f. sp. lactucae，FOL）引起的，在全球范围内对保护地和大田作物造成严重的经济损失。该病原体是F.尖孢属物种复合体，其包含多个适应宿主的致病性特化型（f. spp.）以及非致病性分离株。因此，FOL是一种高度适应的宿主特异性病原体。抗病莴苣品种已被培育，以减少由于FOL的损失，但新的病原体种族已经发展，以克服这种阻力。最近，欧洲出现了4号种族（FOL 4），并在英国和爱尔兰造成了广泛的损失。到目前为止，FOL 4仅限于保护生菜，但有证据表明，它可能比FOL 1更具侵略性，特别是在低温下;因此，户外生产存在重大风险。值得注意的是，在保护下广泛种植的莴苣类型中没有莴苣对FOL 4的抗性，因此开发抗性品种是非常可取的。该项目的主要目的是鉴定和鉴定莴苣中FOL 4抗性的新来源，并鉴定与该性状相关的基因组区域或特定基因。进一步的工作将比较FOL 1和FOL 4的遗传学和生物学，以确定与莴苣品种特异性相关的毒力基因互补和/或突变。此外，将检查感染过程的生物学方面，包括FOL 1和FOL 4定殖和感染不同莴苣品种的能力。非致病性F.尖孢木霉属（Trichoderma spp.）减少FOL也可以探索。

Fusarium wilt disease of lettuce, caused by the soilborne fungus Fusarium oxysporum f.sp. lactucae (FOL), results in severe economic losses in protected and field-grown crops globally. The pathogen is part of the F. oxysporum species complex which comprises multiple host-adapted pathogenic formae speciales (f.spp.) as well as non-pathogenic isolates. FOL is therefore a highly adapted, host specific pathogen. Disease resistant lettuce cultivars have been bred to reduce losses due to FOL but new pathogen races have evolved to overcome this resistance. Recently, race 4 (FOL4) emerged in Europe and has caused extensive losses in the UK and Ireland. So far, FOL4 is confined to protected lettuce but anecdotal evidence suggests it may be more aggressive than FOL1, especially at low temperatures; hence there is a significant risk to outdoor production. Significantly, there is no lettuce resistance to FOL4 in the lettuce types widely grown under protection and hence development of resistant cultivars is highly desirable.The main aim of this project is to identify and characterise new sources of FOL4 resistance in lettuce and identify areas of the genome or specific genes associated with this trait. Further work will compare the genetics and biology of FOL1 and FOL4 to identify virulence gene complements and/or mutations related to lettuce cultivar specificity. In addition, biological aspects of the infection process will be examined including the ability of FOL1 and FOL4 to colonise and infect different lettuce cultivars. The potential of non-pathogenic F. oxysporum and Trichoderma spp. to reduce FOL may also be explored.