Invasive pathogens in nurseries: new detection tools to ascertain the absence of pathogens from consignments
Trade are the main cause of introduction and spread of organisms from other countries, most commonly referred to as “invasive species.” The presence of plant pathogens and insect pests can pose a serious threat to the nursery environment, with considerable loss of production that result in economic losses. The danger is not limited to the nursery, but also extends to the natural environment, where the pathogen could escape causing serious damage to the plants and at the same time compromising the biodiversity of an ecosystem. In many cases, potentially invasive micro-organisms are extremely difficult to diagnose, especially when the infection is initial, because plants for more or less long periods with no symptoms visible to the naked eye, or the symptoms are initially mild and only affect the root system. In addition, these pathogens may be present in water or in growing media even long and without any sign of their presence, and in this case can be carried in pots or in soil attached to the roots of the plants sold. In this context, the ability to quickly detect the presence of pathogenic microorganisms or insects even when present in small quantities, and before they cause damage, is an essential tool for the prevention of the spread of harmful organisms and, therefore, for the certification of goods output from nurseries. Some recently developed techniques allow to identify and quantify the presence of pathogens in different matrices (plants, water, and growing media), even if the plants do not show any visible signs of disease; Moreover, such techniques require short time and can be conducted outdoors or directly in the field and allow to detect the presence of invasive microorganisms in a simple, quick and without the need for specific infrastructures. Early diagnostic techniques therefore allow certification exemption from pathogens in plant material at the start, thus avoiding significant economic losses in terms of time and avoiding the risk of destruction of the material eventually found infected with the country’s borders to its intended use. In addition, in the production chain nursery, early diagnosis combined with targeted methods of struggle, can fight off pathogens before they cause significant damage and reduces their possible spread to other plants in the nursery, in the direct stock to trade and to natural ecosystems . All these objectives can be quickly accessed with the use of a new technique called Loop Mediated Isothermal Amplification (LAMP). LAMP is a nucleic acid amplification which takes place at a constant temperature. The LAMP technique employs a small tool, portable and suitable for outdoor use. It is particularly rapid and allows to obtain accurate and reliable results in very short time, about 20-30 minutes.