EUROPEAN-SEED.COM I EUROPEAN SEED I 7 Seed Sampling: Since most of the seed testing methods are destructive – that is, the seed used in testing is no longer viable, and because seed lots can be of a considerable size, testing is performed on samples. Sampling is of the outmost importance to the validity of the testing results and to the ability to interpret them; to justify the extrapolation of test results obtained by investigating a sample to the quality of its source the sampling scheme must be based on an appropriate statistical rationale and performed correctly. A sample should be of an adequate size to be representative of its source, and should be taken at random and according to a standardized protocol (for a complete description see ISTA international rules; Chapter 2). Seed Quality Tests: The subsequent testing that the sampled seed undergoes is com- prised of a series of analyses designed to assess different aspects of seed quality and include: • Germination tests: these tests are designed to assess the ability of the seed to emerge, develop, and grow into a mature productive plant under standardized and agreed upon set of environmental conditions. There are several methods to con- duct germination tests; for a description of the standard warm germination tests see ISTA or AOSA rules, or information with the Tamil Nadu Agricultural University (TNAU). • Vigour tests: These tests are an extension of the germi- nation tests; while germination is measured under close to opti- mal growth conditions, vigour tests were designed to determine the ability of the seed to emerge and grow into an adult viable plant under conditions that are more stringent and therefore may be a better representation of the conditions the seed will be facing in the field. Some of the vigour tests include a cold test, an accelerated aging test, and a Tetrazolium test. For a complete description, please see publications by ISTA or AOSA, or visit the Seed Laboratory section of Oregon State University. • Seed Purity test: This is a physical inspection of the seed to determine if, and to what extent the seed is free from unin- tended seeds of other crops, weed seeds, and inert matter. For a complete description please see publications by ISTA or AOSA, or visit the Seed Laboratory section of Oregon State University. • Moisture Content: Seed moisture content reflects its phys- iological state at harvest and its post-harvest processing. Since high moisture content is associated with potential poor storability and will have adverse effects on germination, this information is essential in determining seed quality and its future usability. • Variety Identification tests: These tests aim at confirm- ing that the sampled seeds are of the correct variety or genetic makeup. This confirmation is required to prevent cases of adul- teration through seed mixes or outcrossing. As morphological inspection does not provide the required resolution to confi- dently differentiate different varieties of many crops, variety tests usually involve the use of biochemical methods such as isozyme electrophoresis or DNA markers although in some cases grow outs can be used as well. • Trait purity and GMO (Adventitious Presence, AP) tests: These analyses are closely related to varietal identifi- cation; they too interrogate the genetic make-up of the tested seeds but they probe for the presence of specific genetic ele- ments. Trait purity and GMO tests both aim at identifying and quantifying transgenic DNA elements, however, trait purity tests are conducted to assert that the seed is transgenic and carries the intended trait(s), while GMO tests are conducted to confirm the absence of transgenic seeds in conventional seed lots, or the adventitious presence of different events in a transgenic seed lot. • Seed health tests: Disease and pathogens can have dev- astating and long-lasting effects on agricultural productivity. Therefore, it is important to be able to identify, quantify and prevent these threats as early as possible – this is the objective of seed health testing. Testing consists of a combination of a wide array of microbiological, molecular and plant pathology methodologies. The importance of seed health and the risks it may potentially present in international seed movement is exem- plified by the fact that it became the subject of a dedicated, inter- national set of phytosanitary rules: The International Standards for Phytosanitary Measures (ISPM) issued by the Food and Agriculture Organization of the United Nations (FAO) are defin- ing standards for import and export of plant materials and are implemented independently by countries around the world. WHO IS CONDUCTING SEED TESTING? Seed testing has started as a research endeavour in the 19th century, yet in recent years it evolved to be mostly an important facilitator of seed trade, an instrument of regulatory enforce- ment, and an important quality assurance tool for the seed industry. Respectively, the laboratories that conduct seed testing fall mostly in one of the following categories: • Official laboratories: Governmental laboratories per- form seed testing routinely as part of the enforcement of seed laws. Seed testing is conducted at the entry points of the seed into a given market, and includes imported seed, and locally grown seed that needs to be certified. In addition, these labora- tories will often function as “testing for a fee”, similar to com- mercial seed laboratories. • Seed industry laboratories: In the seed industry, seed testing is performed as a quality assurance measure at various junctures along the life cycle of a product. Various tests, such as varietal tests and GMO testing may start as early as during the research and breeding efforts that lead to the development of a given variety, and will continue on a wider scale during production up until the seed is bagged. The specific points of testing will vary based on the general research, multiplication and production practices a company is using as well as other stewardship measures it employs. Company laboratories may also perform seed testing under the authorization of companies to perform some seed certification activities. • Independent, commercial laboratories: The demand for seed testing, mostly in the private domain, far surpasses the volume of testing that government and industry laboratories can provide. This gap created the opportunity for commercial labo- ratory services that provide testing for a fee. Large commercial laboratory networks flourish in Europe and North America and their role is increasing in the rest of the world. • Academic institutions: Many seed testing laboratories are housed within academic institutions. These laboratories may be part of research programs centred on seed technologies but very often they provide testing services to the adjacent agri- cultural community and industry either as part of an extension program or as a commercial testing provider. “Uniformity in seed testing reduces technical barriers, the use of standardized test reports/certificates increases transparency, and together they facilitate seed trade, and benefit the farmer.” – Beni Kaufman