- ALL Barenbrug permanent pasture ryegrass seed is tested for endophyte.
- Type of endophyte is stated (e.g. NEA2).
- Levels are given for the percentage of seed containing endophyte:
- NEA2, NEA, AR1 or AR37 : 70%+ of seed have stated endophyte
- LE or 'Low endophyte' : a low level of seeds have any endophyte
Barenbrug tests endophyte in every line of permanent pasture ryegrass seed. A seed either has, or does not have endophyte, and this endophyte level for a line is given as a percentage e.g. 80% level means 80% of seeds contain endophyte and 20% do not.
For seed to be sold as containing an endophyte a level of 70% or greater is required. This may be NEA2, NEA, AR1, AR37 or another endophyte.
For seed classed as LE (low endophyte) this is seed with a reduced level of endophyte.
Endophyte levels in stored seed can drop over time. To maintain high endophyte levels in commercial seed Barenbrug uses cool storage (see page 185), with regular re-testing of endophyte levels.
The ELISA (Enzyme Linked Immuno Sorbant Assay) test ensures AR1 is not contaminated by Standard endophyte.
The ELISA test determines the presence of Lolitrem B in a seedline. Seed with Standard endophyte always contains Lolitrem B. Seed with AR1 doesn’t contain any Lolitrem B.
The result of the ELISA test is reported as a grade that runs from 1 to 6.
Grades 1-5 are all acceptable for 1st Generation seed, and mean less than 5% contamination. Grade 6 is not suitable for sale.
Testing seed for endophyte
Two tests are available. (Barenbrug offers these as a commercial seed test.)
1. Seed test:
This tests the seed directly. It is a quick test for presence of endophyte, but does not indicate whether the endophyte present is dead or alive. It is used on younger seed, usually up to 15 months old, in which the endophyte is known to be alive.
2. Seedling grow out test:
This is used on older seed, or when there is doubt if endophyte is alive. Seed is sown and the leaf of the resultant seedling is tested for endophyte at 3 - 6 weeks of age. This test is more accurate for older seed as only live endophyte will grow into the seedling.