摘要

Potato seed certification is a disease management tool that minimises the risk of spreading seed tuber-borne inoculum of infectious diseases. Traditionally, certification sampling strategies have relied upon visual assessment of a seedlot from samples taken at one or two points within the load of seed tubers. However methodologies in selection of tuber samples have not been critically assessed for their precision in estimating disease load. This study presents an analysis of 37 potato seedlots over a 3 year period. Analysis of sample data using receiver operating curves (ROCs) indicates that point sampling taking two samples of 100 tubers at the beginning and end of a seedlot gives equivalent disease estimation as a continuous sampling strategy taking ten samples of 20 tubers randomly throughout the seedlot, although at lower statistical precision. This was confirmed both by visual assessment of tuber-borne disease and by analysis of pathogen DNA content from tuber peel. Across the 3 years of study, powdery scab and black scurf were the major seed tuber-borne diseases recognised and this corresponded with high levels of pathogen DNA from peel analysis for both Spongospora subterranea and Rhizoctonia solani AG3 respectively.

  • 出版日期2014-6