Articles
CHLOROPHYLL CONTENT AS INDEX OF ETHYLENE INSIDE CULTURE VESSELS
Article number
447_46
Pages
229 – 230
Language
Abstract
In previous papers the effect of ethylene developing inside the culture vessel was reported to produce negative effects on the growth of plantlets.
The intensity of these effects varied from species to species and their level was estimated empirically, because no quantitative method was available.
On the basis of previous results, two series of plantlets, one of a species very sensitive (apple) and the other tolerant (grapevine), were treated with ethylene inside the vessel (Jona, et al, 1993,a). The rooted plantlets were grown in screw-capped Erlenmeyers.
The annular screw cap is lined with a rubber membrane that allows us remove for analysis samples of inner atmosphere.
The plantlets were grown on cellulose pads (Sorbarod) moisted with half strength liquid MS without hormones Gelling agents were omitted in order to avoid spontaneous production of ethylene, which had been discovered in previous research (Jona, et al 1993,b) and which would have interfered with the experiment.
In order to promote spontaneous, but controlled reaction, ethylene concentration was adjusted, by injection of pure gas, to about 0.2 μl/ml.
Two parallel series of untreated plantlets were run at the same time, as controls, leaving the cap slightly unscrewed, in order to allow the ethylene, which eventually was formed spontaneously, to flow out.
The level of ethylene was measured in all vessels every second day.
A sample of three plantlets was sacrificed every second day and chlorophyll was extracted with a mixture of ethanol and acetone.
The chlorophyll content of the solution was spectrophotometrically measured by OD readings at 6500 Å and 6650 Å. The results proved an inverse relationship between levels of ethylene and chlorophyll.
In this way chlorophyll content could be used to quantitatively evaluate the stress inflicted by ethylene to growing plantlets.
The intensity of these effects varied from species to species and their level was estimated empirically, because no quantitative method was available.
On the basis of previous results, two series of plantlets, one of a species very sensitive (apple) and the other tolerant (grapevine), were treated with ethylene inside the vessel (Jona, et al, 1993,a). The rooted plantlets were grown in screw-capped Erlenmeyers.
The annular screw cap is lined with a rubber membrane that allows us remove for analysis samples of inner atmosphere.
The plantlets were grown on cellulose pads (Sorbarod) moisted with half strength liquid MS without hormones Gelling agents were omitted in order to avoid spontaneous production of ethylene, which had been discovered in previous research (Jona, et al 1993,b) and which would have interfered with the experiment.
In order to promote spontaneous, but controlled reaction, ethylene concentration was adjusted, by injection of pure gas, to about 0.2 μl/ml.
Two parallel series of untreated plantlets were run at the same time, as controls, leaving the cap slightly unscrewed, in order to allow the ethylene, which eventually was formed spontaneously, to flow out.
The level of ethylene was measured in all vessels every second day.
A sample of three plantlets was sacrificed every second day and chlorophyll was extracted with a mixture of ethanol and acetone.
The chlorophyll content of the solution was spectrophotometrically measured by OD readings at 6500 Å and 6650 Å. The results proved an inverse relationship between levels of ethylene and chlorophyll.
In this way chlorophyll content could be used to quantitatively evaluate the stress inflicted by ethylene to growing plantlets.
The empirical assessment, that apple is more sensitive than grapevine to ethylene, was not only demonstrated, but could also be measured.
In the sample of plants grown ethylene-free, chlorophyll increases with time.
Authors
R. Jona, A. Cattro, D. Travaglio
Keywords
Grapevine, Vitis vinifera, Apple, Malus sylvestris
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