Seed Health Testing: Doing Things Right

Abstract

Since seeds can be a route for pathogen introduction, they are routinely inspected and tested to prevent pest outbreaks and introduction into new territories. The need for high throughput, short lead times and cost reduction has played an important role in the development and application of techniques in seed health testing. Examples are molecular and serological techniques, such as ELISA and PCR assays, which are commonly called indirect assays. After signal detection in ELISA or PCR assay a seed lot is a suspect lot that requires further investigation for final conclusion about the health status of the seed lot since these tests do not provide any information about pathogen viability or pathogenicity. The seed industry uses them as pre-screen to identify healthy seed lots, and in combination with classical methods, commonly called direct tests, to confirm viability of the target pathogen and demonstrate its pathogenicity. However, outside industry, indirect tests are increasingly used to make a final decision on the health status of a seed lot. This has led to a growing number of seed lots being rejected where the risk of introducing a pathogen to importing countries may have been negligible. We propose that investments continue to be made in the development of high throughput, pre-screening detection methods like HTS and PCR assays, but together with direct methods that enable accurate assessment of the risks involved when target pathogens are detected using indirect methods. Close collaboration between molecular scientists and classical phytopathologists is essential.

Recent innovative seed treatment methods in the management of seedborne pathogens

“…Seed health testing is therefore a fundamental step in the management of crop diseases (Kulkarni, 2019;Mancini et al, 2016). New and efficient technologies, such as polymerase chain reaction and high throughput sequencing, are increasingly being used to allow rapid and efficient testing of large numbers of samples (Hiddink et al, 2022).…”