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SEED TESTING INTERNATIONAL APRIL 2026
 ASSOCIATION NEWS 
Summary of ISTA Special Project 20-2:  
The development of digital references for the ISTA 
Universal List of Species
Ruojing Wang1 and Deborah J. Lionakis Meyer2
1Project lead, Canadian Food Inspection Agency, Saskatoon, Canada; ruojing.wang@inspection.gc.ca
2Project co-lead, Seed Botanist (retired), Plant Pest Diagnostics Center, California Department of Food and Agriculture, USA
Seed Identification
Retrieving and identifying other seeds are 
routine diagnostic activities in purity analysis 
and other seed determination (OSD). Seed 
identification is the most difficult part of these 
tests to perform and is usually done by highly 
specialised and experienced seed analysts 
based on many years of training and practice. 
When an unfamiliar seed must be identified 
the process often requires an extensive 
search through a seed specimen reference 
collection and seed taxonomic references, as 
morphological comparison to such resources is 
critical to accurate identification. Confidence 
in morphological identification relies on the 
availability of suitable reference materials for 
experienced analysts and those in training, 
leading to accuracy of testing results. The 
development of technical references for OSD 
has long been requested by ISTA members and 
development of such references is strongly 
supported by ISTA.
ISTA Universal List of Species
The ISTA Universal List of Species (UL) provides 
a basic list of commonly encountered species 
in OSD and purity analysis. ISTA accredited 
laboratories are expected, at the minimum, to be 
able to identify the seeds of taxa on the UL.
 
The objectives of the ISTA UL are:
• To state the minimum content that an ISTA 
accredited laboratory could be expected to have 
in its seed reference collection.
• To provide guidance to the ISTA Proficiency Test 
programme for the species that are routinely seen 
in samples.
• To indicate whether seeds can usually be 
identified at the species level.
 
The taxa listed in the UL are frequently present 
in ISTA Proficiency Test panels for OSD or purity 
analysis. However, physical specimens to include 
in a seed reference collection are not always easy 
to collect from verified whole plant specimens 
or from reliable sources of seed, especially for a 
newly accredited seed testing laboratory.
Project co-lead Debbie Meyer, retired seed 
botanist from California Department of Food 
and Agriculture, USA
Sumaia Mahmuda from LAL TEER Seed, 
Bangladesh
Project lead Ruojing Wang (back, left) and team 
from Canadian Food Inspection Agency, Canada
Digital reference for seed testing
Project Objectives
The ISTA Special Project 20-2 aimed to develop 
digital seed identification references of the 130 
taxa on the UL in a web-based format, thus 
providing ongoing support or training to ISTA 
laboratories and seed analysts. The digital  
data references and scientific nomenclature 
could be updated more easily compared to  
paper-based or fixed formats (e.g. PDF files)  
for the 130 UL taxa.

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