The need to study plant viruses in the
Russian Far East is chiefly determined by the fact that its southern region,
Primorye Territory, is an area of intensive farming. Their comprehensive
examination would help lessen crop losses caused by numerous pests and
plant diseases, including viral ones.
Systematic study of viruses and virus-caused
diseases on cultured and wild Primorye flora were begun in 1962 under V.
G. Reifman, Cand. Sci. (Agriculture). Since then, our group of phytovirologists
was reorganized into three laboratories that study the specific composition
of viruses, their distribution and ill effects, ecological role in human
activity and virus-specific proteins and RNA’s, as well as the pathways
and methods of virus distribution and transmitter-insects (aphids, cicadas,
28-spot bug) to elucidate the basic regularities of virus effects on metabolism
of diseased plants by successfully using the method of isolated protoplasts
in examining the penetration of viruses into and reproduction thereof
in cells. For the first time in Primorye’s plant growing practice, immunodiagnostic
methods were introduced involving antiviral sera allowing to select virus-free
material to significantly speed up selection of virus-resistant potato,
soya, vegetable and cereal varieties.
Basic and applied studies involved
biological testing, electron microscopy, peptide mapping, methods of immunochemical
analysis ranging from classical techniques to new-generation methods, viz.
immunoenzymic analysis, rocket immunoelectrophoresis, immunobloating, etc.,
electrophoresis of virus-specific proteins, methods of purifying viruses
and their strains, obtainment of rabbit antiviral antibodies, etc.
Monitoring of basic potato diseases
in Primorye allowed to identify eleven virus, one micoplasma (purple curling
of potato upper leaves) and viroid (spool-like potato tuber) disease.
Soya, the most widespread among leguminous
plants in Primorye, was used to study the most widespread and harmful (affecting
from 50 to 70% of plants) Soya mosaic virus, which inflicts greatest economic
damage and occurs in three strains. With regard to virulence and pathogenicity,
we scrutinized weak-, strong- and medium-pathogenic strains of that virus,
compared their characteristics in infecting Russian, Japanese and Chinese
varieties. Ten viruses were identified in Primorye on leguminous plants,
including three new ones on soya, viz. weak mosaic virus, chlorotic spottiness
and chlorotic leaf deformation virus.
Cereals were used to study the Far
Eastern strain of the northern cereal mosaic virus and the biology of its
sole transmitter, the dark cicada. Other widespread viruses affecting cereals
in Primorye are the brome grass mosaic and striped barley mosaic viruses.
Vegetable crops were used to reveal
various strains of tobacco and common mosaic viruses. Discovered among
them were strongly pathogenic strains inflicting major economic damage
A study of the specific composition
of plant viruses is necessary not only to select stable varieties for Primorye’s
plant growing, but also to forecast epiphytes and develop preventive measures
to protect plants against viruses causing tangible losses.
Apart from its applied significance,
the study of plant viruses adds to our knowledge of basic issues of virology,
since it helps reveal new viruses and their strains, describe the properties
of new and already familiar viruses morphologically, with regard to their
host plants and the physical and physicochemical and antigen characteristics
of viral proteins, and specify the taxonomic position of viruses identified
Quite profound studies are conducted
in Primorye to scrutinize the antigen structure and functions of capsid
proteins as antigens. As a matter of fact, the Institute of Biology and
Soil Science is the only academic institution in Russia engaged in relevant
We studied basic regularities in obtaining
polyclonal antibodies to surface virion proteins and clarified the mechanism
of polyclonal antibody production in various animal species (rabbits, mice,
chicken) under the impact of non-specific immunogenetic factors (immunization,
dosage, reimmunization, and impact of adjuvants, including those of Primorye
We have also improved and developed
optimal conditions of classical and recent methods of identifying virus
For all the viruses examined, we developed
new-generation immunodiagnostic methods for imuunophysical analysis and
methods for their immunodiagnostics. The study of antigen interrelations
between viruses and their strains by modern methods of quantitative immunochemistry
together with results of biological testing and physicochemical characteristics
of capsid proteins and RNA serve as reliable criteria in determining the
taxonomy of viruses and their strains in accord with recent classification.
With the aid of non-immunologic methods
of indirect polymerase chain reaction and DNA-peroxidase probes, we revealed
viral RNAs, and by means of electrophoresis of the viroid RNA the
spool-like form of potato tubers.
Today, we have identified approximately
seventy crop-affecting viruses and their strains in Primorye to assign
them to specific families and species.
In examining further prospects of
phytovirological studies in Primorye, we would like to identify four major
tasks involving: (a) identification and characterization of new pathogens
and their strains; (b) creation of new approaches to identifying vurus=specific
proteins and RNAs and immunization schemes; (c) introduction of highly
sensitive and specific new-generation immunization techniques; (d) introduction
of high-sensitivity new-generation techniques for diagnosing antigens and
antibodies, and development of measures for integrated protection of agricultural
plants in Primorye against viral diseases.