ISSN 1021-4437, Russian Journal of Plant Physiology, 2009, Vol. 56, No. 5, pp. 616–620. © Pleiades Publishing, Ltd., 2009.
Published in Russian in Fiziologiya Rastenii, 2009, Vol. 56, No. 5, pp. 682–687.
(L.) Herit) is an
important aromatic plant yielding geranium oil. Gera-
nium oil have a ﬁne rosy odor with pronounced fruity
minty undertone and a rich long-lasting, sweety rosy
dry out . More than 120 constituents are identiﬁed in
it, and the chief of them are citronellol and geraniol.
Geranium oil is a highly valued essential oil, which is
used in soaps, perfumery, and cosmetic industries. The
cost of oil is increasing in international market, and
attempts were made to promote its cultivation by
employing various agrotechnologies.
The growth and essential oil production of aromatic
plants can be altered by the application of plant growth
regulators. Exogenous application of triacontanol was
found beneﬁcial in improving the herbage yield as well
as artemisinin content in
tion of indole-3-acetic acid resulted in a 4-fold increase
in geraniol content in in vitro developed plantlets and a
2.2-fold increase in 60-day-old plants of
. A significant increase in essential oil accumu-
lation in Japanese mint (
) by chlo-
rmequat chloride was reported .
Brassinosteroids comprise a speciﬁc class of low-
abundance plant steroids now regarded as a new class
This text was submitted by the authors in English.
of phytohormones with a signiﬁcant growth-promoting
activity [5, 6]. The studies conducted with brassinoster-
oid biosynthetic mutants of
 provided compelling evidence
for the essentiality of this new group of growth regula-
tors for normal growth and development. Inhibition
studies employing brassinozole, a speciﬁc inhibitor of
brassinolide synthesis in plants, further fortiﬁed the
view that brassinosteroids are indispensable for plant
growth and development .The ability of brassinos-
teroids to improve the performance of cereals, vegeta-
ble crops, oil seed plants, and fruit crops has been
widely reported [11, 12]. In the present study, the
effects of 24-epibrassinolide on the growth, photosyn-
thesis, chlorophyll, carbohydrate content, and essential
oil production of geranium are investigated.
MATERIALS AND METHODS
24-epibrassinolide (EBL) was obtained from M/s
CID tech Research Inc, Mississauga, Ontario, Canada.
(L.) Herit) Bour-
bon type plant cuttings were obtained from Central
Institute of Medicinal and Aromatic Plants (Hyderabad,
Fresh and healthy plant cuttings 14 cm in height and
having three top leaves (other leaves were carefully
removed) were transplanted into nursery covers ﬁlled
with garden soil and maintained at an adequate mois-
Effect of 24-Epibrassinolide on Growth, Photosynthesis,
and Essential Oil Content of
K. N. Swamy and S. S. R. Rao
Department of Botany, Osmania University, Hyderabad 500007, India;
fax: 91-40-27-09-0020; e-mail: firstname.lastname@example.org
Received February 26, 2008
—The effects of 24-epibrassinolide on growth, photosynthesis, chlorophyll content, carbohydrate
fractions, and essential oil content of rose scented geranium (
(L.) Herit) were investi-
gated. Foliar application of 24-epibrassinolide at 0.5, 1, and 3
M concentrations substantially increased the
growth. 24-epibrassinolide at all concentrations improved herbage yield as reﬂected in the increase of foliar bio-
mass. Exogenous application of 24-epibrassinolide increased the rate of photosynthesis. Growth promotion was
also associated with increased chlorophyll content and resulted in the accumulation of carbohydrate fractions.
M concentration, 24-epibrassinolide increased the total content of essential oils. The quantitative analy-
sis of geranium oil from the geranium plant treated with 3-
M concentration revealed an increase in geraniol
content and decrease in citronellol content. The present study demonstrates a positive impact of the new group
of phytohormones on the performance of geranium plant, a highly valued aromatic plant.
Key words: Pelargonium graveolens - 24-epibrassinolide - growth - photosynthesis - essential oil - carbohy-
drates - chlorophylls