1067-4136/05/3604- © 2005 Pleiades Publishing, Inc.
Russian Journal of Ecology, Vol. 36, No. 4, 2005, pp. 219–226. Translated from Ekologiya, No. 4, 2005, pp. 243–251.
Original Russian Text Copyright © 2005 by Trubina.
In the life cycle of most annual or biennial rosette
and semirosette plants, rosette growth can be distin-
guished as a separate stage of growth and development
at which virtually the entire assimilating sphere of a
plant is formed (Markov, 1990). Rosette size and leaf
surface area largely determine the survival of individual
plants, probability of their transition to blooming, and
reproductive success (Harper, 1977; Gross, 1981; Mad-
dox and Antonovics, 1983; Farris and Lechowocs,
1990; Markov, 1990, 2001; Holderegger, 2000).
In addition to the effects of abiotic and biotic envi-
ronmental factors, differentiation of plants by size
within a population largely depends on individual dif-
ferences in relative growth rate, the size of diaspores,
and the rate of seed germination (Harper, 1977;
Markov, 1990). The results of studies on some plant
species conﬁrm that these differences are determined
genetically and, therefore, the corresponding characters
are subject to natural selection (Burdon and Harper,
1980; Schmid and Dolt, 1994; Byers
, 1997; Pigli-
, 1997; Arntz and Delph, 2001).
Any stress factor, including chemical pollution, has
an adverse effect on the growth of animals and plants.
Numerous examples of rapid selection for ecotypes
resistant to pollution with heavy metals and sulfur diox-
ide are known in plants (Wu
, 1968; Wilson and
Bell, 1986; Alekseeva-Popova, 1990; Meharg
1993). On the other hand, problems concerning the
aftereffects of long-term exposure to pollution on plant
growth and development at the population level have
not received due attention. Our studies on wild popula-
tions of narrow-leaved hawk’s beard,
(Asteraceae), growing under conditions of chronic pol-
lution with ﬂuorine and sulfur compound revealed an
increase in the proportion of plants with a low develop-
mental rate and a signiﬁcant reduction of individual
plant biomass in the most polluted habitat (Trubina,
1996, 2001; Trubina and Makhnev, 1999).
These changes may be interpreted as (1) an ordinary
response to growing conditions, without any signiﬁcant
change in the ratio of fast- and slow-growing individu-
als, or (2) a response to stress accompanied by an
increase in the proportion of individuals with low rates
of growth and development in the affected populations.
Moreover, (3) the proportion of fast-growing individu-
als may increase in such populations: plants with small
seeds prevail in them (Trubina, 2001), and there is evi-
dence for an inverse correlation between seed size and
individual growth rate in seed progeny (Farris and
Lechowicz, 1990; Shipley and Peters, 1990; Meyer and
Carlson, 2001). However, some authors revealed either
a direct correlation between these parameters (Markov,
1990) or no correlation at all (Choe
, 1988; Vaugh-
ton and Ramsey, 1998).
The growth of metameric organisms has two
aspects: increase in the number of metameres and
increase in their size. In plants from
lations growing in polluted habitats, the number of
metameres in the leading shoot is slightly greater,
whereas the metameres proper are slightly smaller than
in plants from clean areas (Trubina, 1996; Trubina and
Makhnev, 1999). Polymerization of homologous struc-
Intrapopulation Differentiation by the Rates of Rosette Growth
and Individual Plant Development in Narrow-Leaved Hawk’s
L.): Aftereffects of Long-Term Stress
M. R. Trubina
Institute of Plant and Animal Ecology, Ural Division,
Russian Academy of Sciences, ul. Vos’mogo Marta 202, Yekaterinburg, 620144 Russia
Received September 25, 2003
—Aftereffects of exposure to long-term chemical pollution with ﬂuorine and sulfur compounds on
intrapopulation differentiation of the rates of growth and development has been studied on
progenies obtained from seeds collected in a pollution gradient and grown in a greenhouse under uniform eco-
logical conditions. The results have shown that long-term stress (exposure to toxic gaseous pollutants) leads to
signiﬁcant changes in the intrapopulation structure, which are manifested in an increase in the proportion of
plants with a low rate of development, a low relative rate of the linear growth of metameres (leaves), but a higher
relative rate of their formation.
: relative growth rate, developmental rate, annual and biennial plants, intrapopulation differentiation,
adaptation, pollution, environment.