242
BIOECOLOGICAL CHARACTERISTICS OF PLANTS
OF RHAPONTICUM
INTEGRIFOLIUM
C. WINKL.
a
Alieva N.K.,
b,c
Bobaev I.D.,
c
Usmonova Z.U.
a
Kokand Pedagogical Institute,
b
Tashkent Institute of Chemical Technology,
c
Tashkent Pharmaceutical Institute
Rhaponticum integrifolium
C. Winkl is a plant species in the family Asteraceae that is
widely used in traditional medicine in Central Asia.
R. integrifolium is
now of economic importance
and some have been introduced into cultivation as medicinal plants. Species of practical interest
include
Rhaponticum integrifolium
[1, 2].
The complete ontogeny
of Rh. integrifolium
was studied under planting-growing conditions
in Chodak (Namangan province) and Gilan (Kashkadarya province) in 2002-2020.
Under laboratory conditions, increasing the temperature from 18
C to 28
C had a positive
effect on seed germination
of Rh. integrifolium.
Seed germination of the plant was found to be very
sensitive to the stratification process (27-33%). Under field conditions, the maximum germination
of
Rh. integrifolium
seeds is observed when they are planted in October-November in mechanically
treated, refrigerator-stored form (68-75%). Under such conditions, seeds germinate 20-25 days
earlier compared to untreated seeds under favourable weather conditions and form a root system
before air temperature rises and the 10-20 cm soil horizon dries out.
Seed sizes of
Rh. intégrifolium
distributed at different geographic latitudes and longitudes
differ sharply from each other. (Chodak: length 0.9±0.25 cm, width 0.25±0.11 cm, weight 1000
seeds 22.5±0.67 g; Gilan: length in average 1.1±0.15 cm, width 0.37±0.13 cm, weight 1000 seeds
23.5±0.94 g).
The seeds
of Rh. Integrifolium
is above-ground, with the primary (main) root germinating
from the seed. After reaching a root length of 1.5-2 cm, the rapidly developing seed leaves rise to
the soil surface. The new seed leaves are 1.5-2 cm long and 0.6-0.7 cm wide.
From the first sprouted plants, true leaves will form in the middle of the seed leaves by 20-
25 April. By this time, the root system of the seedling is formed and reaches 6-9 cm. Under natural
conditions, 2-3 % of the seedlings survive. However, in the experimental plots, with the help of
appropriate agronomic measures, this figure is reached up to 80-85%.
The plant enters the juvenile stage after 20-24 days. This stage is substantiated by the
formation of 6-10 root leaves, the emergence of a new underground organ, the stem-root, active root
formation and the formation of dormant buds at the root. At the beginning of the stage, 3-5 days
after the formation of the first emerging leaf, the second true leaves appear. The subsequently
formed leaves
of Rh. integrifolium
differ from the previous leaves in the coarseness of the petiole
and leaf lamina and the accelerated development.
During the juvenile stage, one of the important morphological changes observed in the plant
is the thickening of the hypocotyl and the formation of adventitious roots that form in the inner
tissues. At the same time, a subterranean organ, a stem-root with a new functional structure, is
formed. During the juvenile stage, 2-6 cone-shaped buds are formed in the above-ground part of the
stem, in the lower centre of the leaf petioles - developing in the following spring.
The vegetation
of Rh. integrifolium lasts
from late July to the first decade of August and
ends with the formation of up to 6-7 root leaves in each individual.
In our view, the absence of an immanent stage in the Uzbek context
References
1.
Alieva N.K., Nigmatullaev A.M., Ramazanov N.Sh., Bobaev I.D. Dynamics of ecdysterone
accumulation in
Rhaponticum integrifolium //
Chemistry of natural compounds. 2009. № 1. P. 115.
2.
Alieva N.K., Nigmatullaev A.M., Ramazanov N.Sh., Bobaev I.D., Mukhtubaeva S.K.
Restoration of stocks of aboveground mass
of Rhaponticum integrifolium
after its harvesting / IV
International. scientific conference "Innovative development and the demand for science in modern
Kazakhstan". Collection of articles. Part 4. Almaty. 2010. P. 298-300.
