1021-4437/02/4904- $27.00 © 2002
Russian Journal of Plant Physiology, Vol. 49, No. 4, 2002, pp. 434–437. Translated from Fiziologiya Rastenii, Vol. 49, No. 4, 2002, pp. 487–491.
Original Russian Text Copyright © 2002 by Aksenova.
March 21, 2002, marked the 100th birthday of
Mikhail Khristoforovich Chailakhyan (1902–1991).
He was a Full member of the USSR Academy of Sci-
ences and the Armenian Academy of Sciences; a mem-
ber of the Academy of Natural Sciences Leopoldina; a
corresponding member of the American Society of
Plant Physiologists and the American Botanic Society;
Doctor Emeritus of Rostock University; and an honor-
ary member of the Bulgarian Botanic Society, the
Indian Society of Plant Physiologists, and the Interna-
tional Plant Growth Substance Association (IPGSA).
For outstanding achievements in biology, Chaila-
khyan was decorated with two Orders of Lenin, the
Order of the Red Banner of Labor, and the Order of
October Revolution. He was one of the ﬁrst researchers
to be awarded with a titular honorary medal of IPGSA.
Chailakhyan was a scientist with a name known world-
wide for his deep and comprehensive studies of plant
growth and development. Until now, his papers, includ-
ing those published in Russian in the 1930s, are cited in
the most high-ranking international journals and funda-
mental textbooks on plant physiology.
Chailakhyan was born in the town of Nakhichevan’-
on-Don in the family of an ofﬁce worker. In 1931, after
graduating from Yerevan University, he became a post-
graduate student at the Laboratory of Biochemistry and
Plant Physiology (LABIFR), then located in Leningrad.
After moving to Moscow, this laboratory was trans-
formed into the Institute of Plant Physiology, the USSR
Academy of Sciences (currently, Timiryazev Institute
of Plant Physiology, Russian Academy of Sciences).
Here, Chailakhyan headed the Laboratory of Growth
and Development and worked there for 56 years, up
until his last days .
Chailakhyan pioneered the investigations of hor-
monal regulation of development in higher plants. He
paid special attention to the problem of photoperiodic,
temperature, and hormonal control of a crucial stage in
the development of higher plants: their transition from
the vegetative state to ﬂowering. These problems pre-
vailed in his investigations throughout his life as a
researcher. His original views on hormonal regulation
of ﬂowering developed and crystallized in the course of
discussions and contacts with many prominent
researchers of his time. When Chailakhyan started his
investigations of plant photoperiodism as a postgradu-
ate student, he was advised by Professor (subsequently,
Academician) N.A. Maksimov. The experiments on
light regulation of the development of spring and winter
wheat that formed the basis for his PhD dissertation
were conducted under the supervision of Academician
A.A. Richter. During the formulation of the concept of
the hormonal control of plant ﬂowering , the meet-
ings and talks with N.G. Cholodny, V.L. Komarov,
D.N. Pryanishnikov, N.I. Vavilov, L.A. Orbeli, V.N. Lyu-
bimenko, and D.A. Sabinin were most helpful .
In 1937, Chailakhyan summed up his views on the
regulation of ﬂowering in the monograph
monal’naya teoriya razvitiya rastenii
ory of Plant Development) , which evoked an enthu-
siastic response from researchers of plant development
in many countries. It is worth noting that the young
A. Lang, who subsequently became a member of the
USA National Academy of Sciences, purposely trans-
lated this book into German so that his teacher, the out-
standing German plant physiologist G. Melchers, could
This book presented the results of classic experi-
ments conducted by Chailakhyan on the photoperiodic
regulation of plant ﬂowering. It was shown that the
Problems of Growth and Development in the Studies
by M.Kh. Chailakhyan
N. P. Aksenova
Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya ul. 35, Moscow, 127276 Russia;
fax: 7 (095) 977-8018; e-mail: email@example.com
Received October 29, 2001
—Main vistas of Academician M.Kh. Chailakhyan’s inquiry into the problems of plant growth and
development are reviewed with the emphasis on the input of his research in elucidating the mechanisms of ﬂow-
ering, tuberization, sex expression, and the integrity of plant organism. The pioneer studies conducted by Chail-
akhyan and his colleagues on agricultural applications of phytohormones, their synthetic analogs, and other
growth regulators are considered. Highlighted is the role of theoretical papers written by Chailakhyan, his lec-
tures, and his brave ﬁght against pseudoscientiﬁc trends in the Russian science is stressed.
Key words: hormonal theory of development - ﬂorigen - ﬂowering - tuberization - growth - sex expression