Биологические науки/6. Микробиология

 

Purlaur V.K., Bitcukova V.P., Khizhnyak S.V., Lankina E.P.

Krasnoyarsk State Agrarian University, Russia

Field assessment of two strains of cold-adapted bacteria isolated from cave microbial community as biological agents for protection of cereals in Siberia

 

The use of ecologically safe biological agents for plant disease control is a good alternative to chemical pesticides, and search for new strains for this purpose is undertaking in many countries [5, 6, 7, 9]. All the existing biolpreparations for biological control of plant diseases are based on the mesophilic bacteria and fungi. It makes these preparations ineffective in boreal climate zone at the beginning of vegetation when soil temperature is about 5-10ºC. From other hand, even non-pathogenic bacteria and fungi used for biological control in agriculture are potentially dangerous for human [10].  The use of psychrophillic and psychrotolerant strains may allow overcoming these problems. High growth rate of such strains at low temperature and their inability to grow at human body temperature makes these strains a good alternative for mesophilic strains in biological control of plant pathogens, especially in the areas with boreal climate [1, 3, 4].

Caves of the Middle Siberia are a natural reservoir of the psychrophillic and psychrotolerant bacteria and fungi [2]. Present study is devoted to the field estimation of two strains of psychrotolerant Bacillus sp. isolated by authors from the Partizanskaya Cave (Eastern Sayan Mountain area, Krasnoyarsk Krai, Russia) as biological agents for control of barley root rot disease caused by Bipolaris and Fusarium species in Siberia.  Both Bipolaris and Fusarium can germinate and form fast-growing mycelium at +6ºC and thus are able to infect plantlets at the very beginning of vegetation when mesophilic strains used for biological control are ineffective [1]. This makes cold-adapted microorganisms preferable biological agents for control of these pathogens.

Naturally infected with Bipolaris and Fusarium seeds of barley (cultivar "Kedr") were treated with a suspension of bacterial spores (10 ml of 108 spore ml-1 suspensions per 1 kg of seeds) and sowed using standard protocol of biological and chemical preparations field assessment [8]. Seeds treated with commercial fungicides were used for comparison; non-treated seed were used as a control. All the experiments were done in 4 replications with 20 m2 plot of land for each replication. Two-year assessments (in 2009 and in 2010) were performed.

During assessments both strains demonstrated statistically significant (p<0,05) effects on the disease symptoms reducing and the yield increasing comparable with effects of chemical preparations. For two years the Strain 5 demonstrated better effect then the Strain 7  (Fig. 1, 2).

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Fig. 1. Effect of bacterization of seeds with psychrotolerant Bacillus (Strain 5 and Strain 7) on the yield of barley in comparison with chemical fungicides (Raksil ultra, Lamador, Vial TrasT, Vitacit, Skarlet, Dividend star, Tabu+Bunker) in 2009

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Fig. 2. Effect of bacterization of seeds with psychrotolerant Bacillus (Strain 5 and Strain 7) on the yield of barley in comparison with chemical fungicides (Raksil ultra, Lamador, Vial TrasT, Vitacit, Skarlet, Dividend star, Tabu+Bunker) in 2009

 

The results of field assessments demonstrates that cold-adapted microorganisms isolated from cave microbial communities may be successfully used for biological control of plant pathogens in the regions with boreal climate.

References

1.                Ilients, I.R. Cave communities of micromycetes as a source of strains for agricultural and environmental biotechnology: PhD thesis. Krasnoyarsk State Agrarian University, Krasnoyarsk, 2011: 140 p. (in Russian)

2.                Khizhnyak, S.V., Tausheva, I.V., Berezikova, A.A., Nesterenko, Y.V., Rogozin D.Y. Psychrophilic and Psychrotolerant Heterotrophic Microorganisms of Middle Siberian Karst Cavities. Russian Journal of Ecology, 2003, 34 (4): 231-235.

3.                Khizhnyak, S.V., Lankina, E.P., Ilients, I.R. Estimation of effectiveness of cold-adapted cave microorganisms in biological control of common root rot of cereals.  Vestnik Krasnoyarsk State Agrarian University, 2009, 6: 49-52. (in Russian)

4.                Lankina, E.P. Cave bacterial communities as a source of strains for biological protection of plants against diseases: PhD thesis. Krasnoyarsk State Agrarian University, Krasnoyarsk, 2011: 140 p. (in Russian)

5.                Pal, K.K. and B. McSpadden Gardener.  Biological Control of Plant Pathogens.  The Plant Health Instructor, 2006: 1-25.

6.                Perello, A.E., Monaco, C. Status and progress of biological control of wheat (Triticum aestivum L.) foliar diseases in Argentina. Fitosanidad, 2007, 11(2): 15-25.

7.                Rajeswari, P. and Kannabiran, B. In Vitro Effects of Antagonistic Microorganisms on Fusarium  oxysporum  [Schlecht. Emend. Synd & Hans] Infecting Arachis hypogaea L. Journal of Phytology, 2011, 3(3): 83-85.

8.                Sanin, S.S., Necklesa N.P. Methodological instructions for factory assessments of means and methods of protection of cereals against diseases. Russian Academy of Agricultural Sciences. All-Russian Research Institute of Phytopathology. Moscow: Plant protection and quarantine, 2008: 32 p. (in Russian)

9.                Shternshis M.V., Dzhalilov F.S.-U., Andreeva I.V., and Tomilova O.G. Biological Protection of Plants / Ed. by Shternshis M.V. Moscow: Koloss, 2004: 264 p. (in Russian) 

10.            Strasser, H. and Kirchmair, M.  Potential health problems due to exposure in handling and using biological control agents. An Ecological And Societal Approach to Biological Control: Kluwer Academic Pub, 2006: 275-293.