ISSN 1067-4136, Russian Journal of Ecology, 2008, Vol. 39, No. 5, pp. 375–378. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © P.V. Kondratkov, 2008, published in Ekologiya, 2008, No. 5, pp. 394–397.
In natural populations, species are represented by a
collection of individuals of differing vitality. This term
refers to the level of metabolic intensity, the capacity
for passing through the complete life cycle, resistance
to stress, and other characteristics. Integrated estimates
of vitality reﬂect changes in the cenotic environment
and ecological factors (Zlobin, 1989, 1996).
Mycosymbiotrophism is regarded as a major eco-
logical factor in the life of terrestrial plants. Although
plants are autotrophic, they are not completely autono-
mous in mineral nutrition (Mukhin and Veselkin,
2002). Many authors note a positive effect of mycor-
rhization on plant growth and development: mycor-
rhizal plants grow better, contain more phosphorus and
potassium, and have higher yielding capacity (Mosse,
1972; Khan, 1972; Daft and Okusanya, 1973; et al.).
The purpose of this study was to characterize the
relationship between plant vitality and endomycorrhiza
Studies were performed in the Iset’–Sysert’ inter-
ﬂuve (Sverdlovsk oblast), in the subzone of pre-forest–
steppe pine–birch forests, in July 2005. The cenopopu-
Lam., a tap-rooted
annual, was delimited on the basis of dominant species
(Zaugol’nova et al., 1993). The root system was
cleaned of soil, and the plants were dried in a thermo-
stat at +80
C to an air-dry state. Sample size was
Vitality was estimated by two groups of parameters
characterizing the development of vegetative and gen-
erative organs. The former group included plant height
and weight; the weight, area, and number of leaves; leaf
weight and area; leaﬁness; relative area of leaves; pho-
tosynthetic effort; and the number of metameres. The
area of leaves was determined gravimetrically. The rel-
ative area of leaves was determined as the ratio of this
area to plant weight; the photosynthetic effort, as the
ratio of the weight of leaves to plant weight.
Parameters characterizing the development of gen-
erative organs included the number of inﬂorescences,
their weight, and reproductive effort. The last parame-
ter was calculated as the ratio of the weight of inﬂores-
cences to plant weight (reproductive effort I) or the
ratio of the weight of inﬂorescences to the area of
leaves (reproductive effort II).
Division of the cenopopulation into groups accord-
ing to morphometric indices was performed using stan-
dard mathematical procedures on the basis of a conﬁ-
dence interval (Zlobin, 1989; Markov, 1990; Zaitsev,
1990). As a criterion for one-dimensional ranking, we
used the area of leaves, an important parameter deter-
mining organization and functioning of plant popula-
tions, which is widely used in their analysis (Voronts-
ova and Zaugol’nova, 1979; Zlobin, 1996).
Analysis for mycorrhiza was performed by the stan-
dard procedure (Mukhin and Betekhtina, 2006) involv-
ing root maceration in alkali, aniline blue staining, and
microscopic study of root endings with the assessment
of mycorrhiza development on a ﬁve-grade scale. The
results were processed statistically using the Statistica
6.0 program package.
cenopopulation proved to include
three vitality groups of individuals: well developed
(26%), moderately developed (26%), and poorly devel-
oped (48%) (Table 1). Numerical prevalence of poorly
developed plants is a typical phenomenon in cenopop-
ulations of many segetal species (Markov, 1986, 1990).
According to Lyubarskii and Poluyanova (1984),
poorly developed plants as a reserve group provide for
cenopopulation stability in case of ecological and phy-
tocenotic ﬂuctuations; moderately developed plants
account for biomass growth and, in part, generative
reproduction; and well-developed plants supply seeds
to the cenopopulation and its surroundings.
As follows from Table 1, the area of leaves and their
weight in well-developed plants are twice as large than
in moderately developed plants and ﬁve times greater
Mycorrhiza and Vitality Structure of Cenopopulation
P. V. Kondratkov
Ural State University, pr. Lenina 51, Yekaterinburg, 620038 Russia;
Received March 20, 2007
: cenopopulation, vitality, mycorrhiza, variation.