Performed in the Special Testing Unit:

Ploidy by Cytometry: A test separating diploid and tetraploid ryegrass genotypes, or any genotypes with different chromosome numbers based on the amount of DNA in the nucleus of plant cells. This test can be performed on germinated seedlings or leaf tissue from the greenhouse or field. Currently it is being used for research projects in a broad range of crops.

Phenol Test: A quick test for cultivar identification. It is based on color reaction between phenol solution and seed coat (pericarp). It can be used for wheat, barley, oat, ryegrass and bluegrass.


When a test sample is compared with a pure control check, it can be determined if the sample is pure or mixed with other cultivars.

Clearfield Wheat Bioassay: Determine the percentage of the “Clearfield®” trait (a herbicide tolerant trait) in a population of 400 seed sample that represents a seed lot. The test is completed in approximately 10 days.

Performed in the Germination Unit:

Fluorescence Test for Ryegrass: Determines the fluorescence level of any particular ryegrass sample. It is used to estimate a potential contamination of perennial ryegrass with annual ryegrass. This test is performed on all AOSA ryegrass germinations and is used to calculate AOSA purity results. It is performed on ISTA samples by request and is not used in ISTA purity calculations. *ISTA Accredited Test

Ammonia Fluorescence Test for Fine Fescue: A quick test to distinguish between Festuca ovina and Festuca rubra. The roots of F. rubra fluoresce yellow and the roots of F. ovina fluoresce green when sprayed with a 0.5% solution of ammonium hydroxide. This test is performed on all AOSA fine fescue germination tests. It is performed on ISTA samples by request. *ISTA Accredited Test

Fluorescence Grow-out for Ryegrass: A test involves growing fluorescent ryegrass seedlings using a specific protocol. At the end of the prescribed test period, the plants are evaluated according to their growth habits. The data is used to make AOSA purity calculations as to the percentage of perennial and annual ryegrass in a sample. Growout results may be reported on an ISTA certificate but the results are not used in ISTA purity calculations.

growout-spring-winter-wheatVarietal Fluorescence Level (VFL): This test is required by the National Grass Variety Review Board before releasing a new ryegrass variety describing its inherited fluorescence level or to re-describe an existing variety. It involves fluorescence tests of at least 3000 seeds and a grow-out of the fluorescing seedlings following a specific protocol.

Grow-out of Other Species: A test in which seedlings are grown in greenhouse conditions until they develop characteristics that allow them to be differentiated. This is applicable to a wide range of species and is useful in conditions where normal purity determinations cannot be made with certainty.

Performed in the Purity Unit:

Sodium Hydroxide Test for Wheat (NaOH): A chemical test used to distinguish between red and white wheat in situations where it is difficult to distinguish between the two types (i.e. when seeds have been weather-damaged, treated, or are simply hard to distinguish by the naked eye).