Articles
PHENOLIC COMPOUNDS IN BARLEY VARIETIES WITH DIFFERENT DEGREE OF PARTIAL RESISTANCE AGAINST POWDERY MILDEW
Fungicide treatment caused an increase in grain yield from 3% in the most resistant variety to nearly 20% in the varieties with little resistance.
An unfractionated ethanol extract was made from leaves of plants at different stages and analysed by high performance liquid chromatography.
The extract contained about 15 potential phenolic compounds seen as peaks in the chromatogram.
The sizes of some peaks were strongly positively correlated.
Nine components were present in significant amounts in all five varieties at all three harvest times.
A large quantitative variation in the amount of these components was found among varieties, and one variety contained 4 elements that were absent or very low in the other 4 varieties.
Some of the phenolic compounds were affected significantly by treatment with fungicide or by application of nitrogen fertiliser.
However, these effects were relatively small compared with the influence of plant age or the differences between varieties.
No obvious relations were seen between the degree of partial resistance or mildew attack and the content of some of the components studied.