1. National Referee Agar Media Corn Germination 2016
Melissa Phillips
Monsanto
Seed Technology Center
Waterman, Illinois USA

2. Purpose
The purpose of the referee was to introduce Agar (plant culturing media) as a potential candidate for use in germination testing for corn.
Participants
16 Labs in total signed up to participate
Agar was provided upon request to 7 labs
Seed was sent out June 2016
Data was returned August- Sept
10 labs returned data

3. Previous Studies Protocol
Kept with more traditional studies of “open protocols”
Agar requires more specific requirements
6 corn samples
Samples tested using in-house AOSA approved method and agar media
Process was to be repeated 5-7 days later to establish lab repeatability
Agar concentration to be used 0.8%-1%

4. Agar results are on par with current methods with in each lab.
Repeatability is the closeness of the agreement between the results of the same measure and carried out in the same conditions.
Reproducibility is the precision under reproducibility conditions, i.e. conditions where test results are obtained with the same method on identical test items in different laboratories with different operators using different equipment.
Variance
Method
Mean Germ
Median Germ
Repeatability*
Reproducibility*
Part to Part
Interaction
Total
Agar
84.3 88
28.9 (17%)
29.0 (17%)
99.2 (58%)
15.1 (9%)
172.2
Current
87.1 90
24.2 (19%)
4.3 (3%)
89.0 (70%)
10.5 (8%)
128.0
*Adequate measurement systems have total Repeatability + Reproducibility less than 10% of total variation
Agar results are on par with current methods with in each lab.
Agar results are less reproducible than current methods when compared across multiple labs.
Statistics supplied by Paul Cannon and Kirk Remund- Monsanto

5. Corn Germination Reproducibility

6. Significant Outliers; Why?
Some labs were in alignment,
others were not
Post referee survey
Current Method
CCP or CCP/Sand vs. Rolled Towel
Experience with Agar
First Time to Experienced
Equipment used for agar preparation
Stove
Microwave
Hotplate
Autoclave
Significant Outliers; Why?
What is Occurring?

7. Corn Germination based on agar experience
No conclusions can be made based on experience
* sample numbers are not large enough to be significant

8. Corn germination based on media
* sample numbers are not large enough to be significant

9. Conclusion
Study results were not supportive of a rule proposal for corn germination
Results show that there is still reproducibility issues across some labs
In-lab repeatability is on par with current approved methods
The use of specific protocols increases the repeatability of the agar method

10. Moving Forward Thank you!
Further analysis of factors impacting repeatability and reproducibility
Future Targeted/ Strategic Study
Protocol of corn agar that will allow us to control critical to quality control variables
Thank you!
Special thanks to all of the referee participants!