|Plant Pathology and Weed Research|
|Head: Amit Gal-On, Ph.D.|
|Research in the Department deals with plant diseases caused by fungal and bacterial pathogens and weed research of economic importance in Israel.
Disease management and control.
- Development of disease management programs for fungal and bacterial pathogen control are based on integration of biological, genetic, cultural and reduced chemical applications.
- Evaluation of biological control agents (e.g., Trichoderma and commercial product TRICHODEX) for control of fungal and bacterial diseases especially in greenhouse and other controlled environments.
- Development of forecast models and computerized decision support systems (e.g., BOTMAN, GREENMAN, FBCA) for disease management (grey mold, powdery mildews, fire blight) based on epidemiological data for reduced pathogen (bacterial and fungal) dispersal, establishment and infection.
- Epidemiological studies for evaluating interaction between climatic and biotic factors which affect disease development.
- Treatment of pathogens in water and in recycled irrigation systems.
- Evaluation and development of alternatives to methyl bromide for the control of soilborne pathogens.
- Research in methods for seedborne pathogen control.
- Studies on resistance of fungal and bacterial pathogens to chemical fungicides, bacteriacides and antibiotics.
Pest management in organic farming.
- Classical breeding programs for resistance to various important fungal diseases (e.g. Fusarium in carnation; Colletotrichum in strawberry) in collaboration with breeders from other institutes.
Disease-free plant propagation material.
Development of sensitive and accurate methods for disease identification and pathogen detection based on biological, serological and molecular techniques. Diagnostic methods have been developed for major bacterial (e.g. Erwinia, Xanthomonas, Agrobacterium) and fungal (e.g. Fusarium, Colletotrichum) pathogens of field, fruit, ornamental and vegetable crops. Collaboration with the diagnostic unit of the Plant Protection and Inspection Services, Israel Ministry of Agriculture, in identification of recently introduced pathogens and disorders
Physiology of diseased plants, induced resistance and host-pathogen interactions.
Research in physiology of diseased plants, induced resistance and host pathogen interactions within each researcher's individual program. Fundamental and applied studies at the biochemical and molecular levels for determining pathogenicity factors and plant response.
- Precision application of herbicides and proper utilization of chemical weed control. Study of weed and parasitic plants infestation of arable crops.
- Investigation of alternatives to chemical herbicides.
- Study of biology and physiology of weeds.
- Development of herbicide resistant plants and tolerance to parasitic plants by molecular methods and induced mutations.
Detection and Identification of Plant Viruses.
Several different technologies have been developed and are currently in use in our Department. These methods include electron microscopy (EM), biological tests, serological and molecular techniques such as PCR, RT-PCR, dsRNA analysis and nucleic acid hybridizations. Most of these methods are being used for the production of virus-free propagation material as well as in commercial laboratories for virus diagnosis in vegetatively-propagated crops (bulbs, corms and stems), vegetables, fruit trees and grapes.
Production of virus-free propagation material.
Tissue culture methods, thermo- and chemotherapy have been used either alone or in combination, to eliminate viruses from fruit trees, grapes, a number of vegetatively propagated ornamentals and cut-flowers. The work was carried out in collaboration with researcher from Institute of Horticulture and private nurseries. The list includes citrus, apricot, nectarine, almond, grape, garlic, carnation, lily, hippeastrum, geranium, impatiens, petunia and a long list of pot plants.
Virus transmission and epidemiology
The epidemiology of citrus tristeza virus (CTV) in citrus, cucumber mosaic virus (CMV) and potato virus Y (PVY) in pepper, tomato yellow leaf curl (TYLCV) in tomato, tomato spotted wilt (TSWV) in lettuce and pepper, Zucchini yellow mosaic (ZYMV) in cucurbits, maize dwarf mosaic (MDMV) in corn and a number of viruses in ornamentals and cut flowers. The mode of transmission and virus-vector interactions of the following viruses was studied: Potyviruses-Aphids, Tospoviruses-Thrips, Gemeniviruses-White flies. Control measures were developed based on the acquired knowledge.
Chemicals are used to control plant disease caused by fungi and bacteria. No such direct method for the control of virus diseases is yet available. Viruses are intercellular parasites that proliferate and replicate inside the living cells Most of the procedures that can be used effectively involve preventive measures which include:
- Oil spray to reduce the spread of non-persistent viruses in peppers and cucurbits, oil and detergent combination in additional crops.
- Use of reflective sheets laid on the ground protect peppers and tomato crops.
- Use of white nets in cucurbits and ornamentals.
- Use of UV absorbing plastic sheets in tomato, cucurbits and ornamentals
Breeding for virus resistance.
Breeding is conducted either by conventional crossing in collaboration with breeders or by transgenic protection, using viral genes. Tolerant as well as resistant tomato against TYLCV and CMV were developed, both by conventional crossing and molecular transformation.
Infection of a plant with a mild strain of a virus, may protect it form infection with severe strains. A wild type mild strain of ZYMV is being commercially used as a protective measure against severe strains in Zucchini and watermelon. Parallely, by sequence comparison a newly mild ZYMV was genetically engineered in our Department.
Development of transformation and regeneration system in tissue culture.
Methods for regeneration and transformation in tissue culture of melon, cucurbits, potato, Nicotiana spp., Petunia spp., Ornithogalum and Lily were developed.
Structure and function of viral genome.
The structure, full genome sequence and function of viruses including ZYMV, CTV, TYLCV and GVA, were studied .Partial sequence of several viruses infection fruit trees, vegetables, grains, ornamentals and cut flower crops was determined. The use of the N-terminal region of the Potyvirus coat protein as a competitor for virus acquisition by aphid.
Use of viruses as expressing vectors of foreign genes.
Infectious clones of ZYMV, and GVA were engineered as vectors to express foreign genes in their host plants. Such methods were developed and employed by replacing viral genes with foreign genes, that upon infection produced the required protein by the host plant. These virus systems can be used as a simple and efficient tool for foreign gene expression in plants.
Staff members located at the regional centers:
|Name (Surname, First name)
||Research Interests / Job description
|Dombrovsky Aviv, Ph.D.||
||Transmission of plant viruses
|Elad Yigal, Prof.||
||Diseases of covered crops; Foliar diseases; Integrated
|Ezra David, Ph.D.||
||Fungal fruit tree diseases:
Mal secco disease of
|Freeman Stanley, Ph.D.||
||Foliar and soilborne pathogens of vegetable and fruit
|Frenkel Omer, Ph.D.||
||Soil borne pathogens ecology
Population biology of plant
|Gaba Victor, Ph.D.||
||Plant tissue culture and transformation for plant
|Gal-On Amit, Ph.D.||
||The molecular basis of host and positive-strand RNA virus
|Gera Abed, Prof.||
Molecular and biotechnological
|Korolev Nadia, Ph.D.||
||Fungal populations, soilborne and foliar fungi, fungal
|Manulis-Sasson Shulamit, Ph.D.||
||Studies on the molecular basis of bacterial-host
|Mawassi Munir, Ph.D.||
||Engineering of grapevine virus-based transient expression
|Shtienberg Dani, Prof.||
||•Epidemiology of plant disease.
|Name (Surname, First name)
||Research Interests / Job description
|Antignus Yehezkel, Ph.D.||
||Molecular and biological characterization of vegetable
|Bar Joseph Moshe, Prof.||
||Management and control of virus and virus like disease
|Ben-Yephet Yephet, Ph.D.||
||Soil borne pathogens in vegetables, flowers and peanut in
|Haas Jerry H, Ph.D.||
||Ecology and epidemiology of soil-borne fungal pathogens and
|Katan Talma, Ph.D.||
|Kritzman Giora, Ph.D.||
||Plant Pathologist & phytobacteriologist: Soil borne,seed
|Loebenstein Gad, Prof.||
||Plant Virology, Viuses of sweet potato and potatoes; rapid
|Raccah Benjamin, Prof.||
||Virus-vector relationships at the biological and molecular
|Rosner Arieh, Ph.D.||
|Solel Zvi, Ph.D.||
||Fungal diseases of citrus.
Epidemiology, resistance and
|Spiegel Sara, Ph.D.||
|Tanhe Edna, Ph.D.||
|Zutra Dan, M.Sc.||