Abstract

Late blight caused by Phytophthora infestans is a serious threat to potato production. Currently, solutions to manage late blight in organic systems are scarce. This study was undertaken to evaluate the effect of selenium (Se) on plant emergence from seed pre-treated with Se and the seed decay pathogens Pectobacterium carotovorum ssp. carotovorum and Fusarium sambucinum, and on foliar potato late blight following inoculation with P. infestans and foliar treatment with Se. The potential modes of action of Se were also evaluated. Following inoculation of the seed decay pathogens on potato seed pre-treated with different rates of Se, plant emergence was not affected by Se treatment. By pre-treating potato seed with different Se rates, and applying different foliar Se rates on potato plants subsequently inoculated with the late blight pathogen in a greenhouse setting, we showed that foliar Se application alone or combined with Se seed treatment reduced the severity and incidence of late blight, and activated the production of secondary metabolites in potato leaves and tubers. Further, in vitro studies showed that Se directly inhibited the mycelial growth of P. infestans and other important plant pathogens, including Fusarium graminearum and Sclerotinia sclerotiorum. The data suggest that Se acts as an inducer of plant defences, while also inhibiting fungal growth. The study highlights the potential of Se for managing late blight, and suggests that its application could contribute to improving plant health in greenhouse production systems by helping to control diseases caused by P. infestans, F. graminearum and S. sclerotiorum.

摘要

由致病疫霉引起的晚疫病是对马铃薯生产的严重威胁。目前，管理有机系统晚疫病的解决方案很少。本研究旨在评估硒 (Se) 对用 Se 预处理的种子和种子腐烂病原体Pectobacterium carotovorum ssp 的植物出苗的影响。carotovorum和Fusarium sambucinum以及在接种P. infestans后的叶面马铃薯晚疫病上并用硒进行叶面处理。还评估了硒的潜在作用方式。在用不同的硒预处理过的马铃薯种子上接种种子腐烂病原体后，植物出苗不受硒处理的影响。通过以不同的硒含量预处理马铃薯种子，并在随后在温室环境中接种晚疫病病原体的马铃薯植株上施用不同的叶面硒含量，我们发现单独叶面施用硒或与硒种子处理相结合可降低严重程度和发病率晚疫病，并激活马铃薯叶和块茎中次生代谢物的产生。此外，体外研究表明，硒直接抑制致病疫霉和其他重要植物病原体的菌丝体生长，包括禾谷镰刀菌和核盘菌。数据表明，硒作为植物防御的诱导剂，同时也抑制真菌的生长。该研究强调了硒在管理晚疫病方面的潜力，并表明硒的应用有助于控制由致病疫霉、禾谷镰刀菌和核盘菌引起的疾病，从而有助于改善温室生产系统中的植物健康。