Diseases

Pseudomonas syringae pv.glycinea (Coerper) Young et al. - Bacterial Spot (Bacterial Burn) of Soybean.

Systematic position.

Kingdom Procaryotae, section Gram-negative aerobic rods and cocci, family Pseudomonadaceae, genus Pseudomonas.

Synonyms.

Bacterium glycineum Coerper, V. sojae Wolf, Pseudomonas glycinea Coerper,
P. sojae (Wolf) Stapp, Phytomonas glycinea (Coerper) Burkholder, Ph. sojae (Wolf) Burkholder.

Biological group.

Hemibiotroph.

Morphology and biology.

Pathogen attacks all ground parts of the soybean during its development from seedling to adult plant. Bacteriosis occurs more often on leaves. Fine,light brown oily spots are formed on the lower side of diseased leaves. Later the infected tissue becomes a chocolate color, appearing transparent by transmitted light. These spots usually settle on the ribs and along leaf margins of the plant. The diseased parts of leaves usually have a yellow-orange limb. Later the diseased parts of tissue become larger and dark brown to black in color. This tissue drops out where the lesions form and the leaf becomes disfigured. Sometimes exudation appears on the lower leaf side. After hardening, it appears to form a thin silvery film. Spots on cotyledons are gray-brown and oily and later dry up. On diseased stems, the spots are oblong and later darken. Spots on beans are round and dark-brown. As a rule, diseased seeds are smaller in size than healthy ones and are dim and wrinkled. Cells of P. syringae pv.glycinea are straight bacilli, usually 1.2-1.5 x 2.3-2.9 mkm in size, moving by means of polar flagella. Gram-negative. Producing fluorescing pigment. Not diluting gelatin. Forming levan. Oxidase reaction is negative. On nutrient mediums, colonies are round, smooth, brilliant, with even or slightly wavy borders. Not producing indol and H₂S. Curdling milk, but not peptizing. It does not restore nitrates nor hydrolyzing starch; forms acid in the medium with dextrose and saccharose. Optimum temperature for growth is 24-25°C, maximum 35°C. The primary infection is kept in the diseased vegetation residues and seeds of peas until the following season.

Distribution.

Bacteriosis has a wide distribution in all soybean areas, including the USA, Czech, Slovakia, Bulgaria, Mongolia, Brazil, Southern Africa. The disease meets in all territories of the former Soviet Union where this culture is grown; i.e., in the Far East, the Lower Volga region, Krasnodar, Stavropol Territories and Ukraine.

Ecology.

The infection develops favorably at high temperature (25-30°C) and sufficient relative air humidity. Rainy weather, strong wind and hailstones promote mass distribution of the bacteriosis.

Economic significance.

Bacteriosis causes premature leaf fall and reduction of their assimilation surface by 40-50%. It affects on amount of yield and may cause destruction of both seedlings and adult plants. In the diseased plants, the intensity of breathing and transpiration increase, while photosynthesis and amount of chlorophyll in leaves decrease. Mass appearance of this bacteriosis is observed in the second half of the vegetation season during the secondary infection of plants. The bacteriosis lesion depends substantially on a variety and climatic conditions. In the Far East (Primorskii Territory), the amount of infected plants reaches 40%, in some years 70-100%, and the yield is reduced by more than 25%. Control measures include a complex of various agronomical actions which should be directed toward cultivation of healthy plants. These include maintenance of crop rotation, selection of resistant varieties, correct entering of mineral fertilizers, pesticide treatment of plants during vegetation, and careful destruction of vegetation residues.

Reference citations:

Bilai V.I., Gvozdyak R.I., Kraev V.G., Ellanskaya I.A., Zirka T.I. & Muras V.A. 1988. Microorganisms are the pathogens of diseases of plants. Kiev: Naukova dumka, 552 p. (in Russian).
Gorlenko M.V. 1947. A survey of geographical distribution of bacterial plant diseases in the USSR. Byulleten obshchestva ispytatelei prirody, otdelenie biologii 32 (2): 61-70 (in Russian).
Gorlenko M.V. 1949. Results of studying bacterial diseases in the USSR for 30 years (1917-1947). Mikrobiologiya 18 (1): 71-81 (in Russian).
Gorlenko M.V. 1966. Bacterial diseases of plants. Moscow: Vysshaya shkola, 291 p. (in Russian).
Izrail.skii V.P. 1960. Bacterioses of leguminous plants. In: Israel.skii V.P., ed. Bacterioses of plants. Moscow: Gosudarstvennoe izdatelstvo selskokhozyaistvennoi literatury, p.221-227 (in Russian).
Kiryukhina R.I., ed. 1979. Diagnostics of bacterial diseases of leguminous cultures and measures of their control. Methodical recommendations. Moscow: Kolos. 28 p. (in Russian).
Korsakov N.I., ed. 1982. Investigation and diagnostics of pathogens of bacterioses, studying resistance of annual leguminous cultures to them. Methodical instructions. Leningrad: VIR. 90 p. (in Russian).
Kotova V.V., Shekunova E.G. & Bushkova L.N. 1969. Diseases of leguminous cultures. In.: Polyakov I.Ya. & Chumakov A.E., eds. Distribution of pests and diseases of agricultural crops in RSFSR in 1968 and the forecast of their occurrence in 1969. Moscow: Rossel.khozizdat, 1969, p. 103 (in Russian).
Matveeva E.V. & Ostrogskaya N.A. 1966. Serological method of definition soybean bacterioses. In: Bel.tyukova K.I., ed. Abstracts of reports of the All-Union symposium on bacterial diseases of plants. Kiev: Naukova Dumka, p. 53-54 (in Russian).
Nikitina A.I. 1962. Dangerous soybean diseases in the Far East. Zashchita rastenii protiv vreditelei i boleznei 7: 37-40 (in Russian).
Pavlyushin V.A., ed. 2006. Bacterioses of leguminous cultures and measure of their control (Methodical recommendations). St.Petersburg: VIZR. 41 p. (in Russian).
Podkina D.V., Nikitina K.V., Belekhova K.A., Andreeva L.T. 1980. Soybean bacterial diseases in the Krasnodar Territory. In: Korsakov N.I., ed. Byulleten VNIIR. Leguminous cultures.V. 97. Leningrad: VIR, p. 70-73 (in Russian).
Shchelko L.G., Demchenko V.P., Prostakova Z.G., Lazarev A.M. 1988. Problems of selection of soybean by immunity in the Central Asian Republics. Use of world collections of field cultures for creation of varieties of intensive type in conditions of Uzbekistan. Works of VIR (Central Asian part). Leningrad: VIR, p. 85-93 (in Russian).
Solotchina G.F. 1966. Biological substantiation of actions on restriction of severity of soybean bacterioses in Primorskii Territory. In: Bel.tyukova K.I., ed. Abstracts of reports of the All-Union symposium on bacterial diseases of plants. Kiev: Naukova Dumka, p. 52-53 (in Russian).
Solotchina G.F. & Pekhtereva E.Sh. 1966. Specific structure of pathogens of soybean bacterioses in Primorskii Territory. In: Bel.tyukova K.I., ed. Abstracts of reports of the All-Union symposium on bacterial diseases of plants. Kiev: Naukova Dumka, p. 51-52 (in Russian).
Vzorov V.I. 1938. Species and spreading of bacteriosis of agricultural plants in the Soviet Union. In: Borover S.Ya., ed. Byulleten Rostovskoi stantsii zashchity rastenii 9: 87-91 (in Russian).
Yagudin V.D. & Shklyar S.N. 1979. Bacterioses of soybean. In: Izrail.skii V.P., ed. Bacterial diseases of plants. Moscow: Kolos, p. 53-56 (in Russian).

© Lazarev, A.M.

Photo is taken from Archive of documentary photographs of Federal Management on research of selection of cultural plants (Aschersleben, Germany) and is published with kind permission of Prof. Dr. K. Naumann (Germany).