Agriculture Reference
In-Depth Information
Figure 9.8. The luorescence test for oats: Left: white (luorescent) oats; right: yellow (nonluorescent) oats.
Hard and red fescue (
Festuca
spp.) fluorescent Ammonia Test
This test is used to distinguish between two ine fescue species, red (
Festuca rubra
L. spp.
rubra
) and hard
(
F. brevipila
Tracey) fescue, which is dificult to differentiate based on morphological seed or seedling
characteristics.
Using the ammonia luorescence test, the roots of red fescue luoresce yellow and those of hard fescue
luoresce green when sprayed with a dilute (0.5%) solution of ammonium hydroxide and placed under
ultraviolet light (AOSA Cultivar Purity Testing Handbook).
Procedure
1. Conduct this test in light [not to exceed 100 foot candles (1080 lux)] with white ilter paper as a
substratum.
2. Place ilter paper moistened with distilled or deionized water in plastic boxes with covers.
3. Plant four 100 seed replicates in such a manner that the roots of adjacent seedlings will not come
in contact with each other.
4. After planting, place in a 15-20°C germinator in an upright, slant position at an angle of approxi-
mately 60-65°.
5. Adequate moisture levels are critical for this test. Additional moistening may be necessary
throughout the test period.
6. On the tenth day, remove all ungerminated seeds, seedlings too immature to evaluate, and abnor-
mal seedlings. Place them on fresh substrata and return to the germinator. Take care not to damage
the seeds or seedlings during transfer.
7. The normal seedlings remaining on the original substrata should be lightly sprayed with 0.5%
ammonium hydroxide (1.67 ml concentrated ammonium hydroxide [reagent grade 28-30%] added
to 98.33 ml distilled water).
8. After approximately one minute, record the number of green and/or yellow luorescent seedling
roots under ultraviolet light. Red fescue seedling roots luoresce yellow while those of hard fescue
luoresce green.
9. On the 14th day, repeat the ammonia luorescence test steps 7 and 8 on any normal seedlings
which develop from seeds or seedlings transferred to fresh substrata at ten days. If, at the end of
