Seed testing preventing the introduction of quarantine pathogens

摘要

Seed-borne plant pathogens can be easily moved around the world into new environments, which, if favourable to the pathogen, can lead to poor plant establishment as well as a reduction in the yield and quality of the crop (direct costs). Trade restrictions may be imposed on the affected country or region if the pathogen concerned is listed as a quarantine pest by other importing countries (reaction costs). Affected countries may have to implement stringent and costly control strategies to deal with outbreaks in order to regain lost export markets. As such, many countries require seed to be certified free from these pathogens as part of their phytosanitary import requirements. Several organisations and initiatives publish protocols to diagnose seed-borne pathogens, including the International Seed Testing Association (ISTA) and International Seed Health Initiative (ISHI). Other protocols are also published in handbooks (e.g. Albrechtsen, 2006; Mathur & Kongsdal, 2003; Saettler et al, 1989) and scientific journals such as Seed Science & Technology. Unfortunately, many of these rely on destructively testing large numbers of seed, some of which, such as tomato and tree seed, can be extremely valuable. This can make some exports untenable on the grounds of cost and/or the availability of test seed.