SYMBIOTIC EFFECTIVENESS OF AUTOCHTHONOUS Bradyrhizobium japonicum STRAINS
: REDŽEPOVIĆ, SULEJMAN (40561) Assistants
SIKORA, SANJA (85451)
MANITAŠEVIĆ, JELENA (71326)
ŠOŠKIĆ, MILAN (66031)
ŽAFRAN, JELENA (900443)
Type of research: applied Duration from: 01/01/91. to 12/31/00. Papers on project (total): 26
Institution name: Agronomski fakultet, Zagreb (178) Department/Institute: DEPARTMENT OF MICROBIOLOGY Address: Svetošimunska 25
Phone: 385 (0) 1 2335 777
Fax: 385 (0) 1 2335 777
Summary: Symbiotic nitrogen fixation has already given a significant
ecological and economic contribution to agricultural production. Relating
to the main research objective of this Project, detailed laboratory
investigations, pot experiments under controlled conditions and field
trials will be carried out to enable selection of the most effective
symbiotic association of soybean genotypes and Bradyrhizobia strains.
Investigations will involve isolation of autochthonous strains of B.
japonicum; RAPD analysis (Random Amplified Polymorphic DNA), serological
and antibiotic identification of strains; assessment of cultivar-strain
compatibility; determination of nitrogenase and hydrogenase activity. Thus
tested and thoroughly checked strains will be studied in field trials on
different locations, with special attention being paid to the influence of
mineral nitrogen fertilization upon the effectiveness of the B. japonicum
strains selected. Isolated autochthonous strains, if any, possessing also
the enzyme hydrogenase (hydrogen uptake positive), which are rare in
nature, will be investigated in great detail. Our own collection of B.
japonicum strains will be formed so as to preserve the original genetic
material, which could be a prerequirement for connection to the developed
Research goals: The main goal is isolation and determination of
autochthonous strains of Bradyrhizobium japonicum from different
ecological regions of the Republic of Croatia to enable selection of the
most efficient strains and determine the most effective symbiotic
associations for the soybean genotype. Identification and selection of B.
japonicum strains are important for the use of strains in preparing
commercial inoculants for bacterization of soybean, as well as for
preserving our own original genetic material for future research. There
are reasons to believe that the quality of soybean, as a significant
legume, can be improved by application of symbiotically bound nitrogen.
Considerable economic effects can be achieved by the application of
isolated, autochthonous, effective B. japonicum strains in the pre-seeding
bacterization of soybean since the expensive mineral nitrogen can be
reduced to a minimum. At the same time, ecological hazards related to
excessive use of mineral nitrogen fertilizers are decreased.
Investigations could also explain the existing interdependence between
particular properties to be studied in the symbiotic system of the soybean
genotype and B. japonicum strain, which could theoretically result in
creation of more reliable criteria that would shorten selection paths of
both partners. Other information about the project.