ecological and genetic variability of chlorophyll a and b contents in
scots pine needles
1Kalchenko L.I., 2Artymuk S.Y., 3Tarakanov V.V., 2Ignatiev
1Forest Protection Centre for the Altai Krai,
2Institute of Soil Science and
3West-Siberian Office of the Institute of
Forest, Russia, vvtarh@yandex.ru
Estimation of genetic heterogeneity
of forest-forming tree species is of undoubted interest, especially for such
basic biochemical characteristic as the content of chlorophylls a and b in
needles. The published information is
rather controversial about the genetic character of the latter. So we studied
the structure of chlorophyll content variability, i.e. the ratio of ecological and genotypic variance components, in the 2-yo
needles of different clones Pinus sylvestris L.
Overall 33 trees, aged 18 years, of 13 clones were analyzed. The needles were sampled on two dates: in July
(active growth) and December (no growth). Chlorophyll was extracted by ethanol
and then determined colorimetrically.
Winter needles had 10% lower
chlorophyll concentration as compared to the summer ones, with the ratio of a and b chlorophylls changing little. The correlation
between a and b forms was high and positive (0.8÷0.9).
The structure of chlorophyll content variance was estimated by ANOVA as the contribution of interclonal variance into the total variance. The effect of clones was statistically
significant (P<0.001) for all variables, i.e. chlorophyll a and b content, their
total amount and a/b ratio. The interclonal variance
contributed as much as 65-75
% into the total variance, thus confirming genotypic character of the
variables. However, analysis of correlations between averaged over seasons (summer-winter) variables
revealed strong effect of the genotype-environment interaction factor. Two
variables (chlorophyll a content and a/b ratio) showed nearly statistically
significant interclonal correlations (r~0.5).
So the content of different
chlorophyll forms was showed to be genetically controlled, but the genotype may
change ranks due to environmental conditions, namely season of a year. We
believe the estimation of chlorophyll content variability in pine needles
should be done taking into account the effect of limiting environmental
factors. If such information is unavailable, for comparing different sets of
data it is better to sample tree phytomass in the state
of physiological dormancy.
We discuss
the results of correlation analysis of the interrelationship between
chlorophyll content in winter needles and variables describing the growth
intensity of clones, stressing the need for further studies.