StatusThe thesis was presented on the 4 December, 2018
Approved by NCAA on the 25 January, 2019
Abstract– 7.07 Mb / in romanian
16.00 Mb /
The thesis for doctor degree in agricultural sciences, specialty 411.09 -Plant protection, Chisinau, 2018. The thesis consist of an introduction, 4 chapters, general conclusions and practical recomandations, 213 references, 146 pages of text, 34 tables, 62 figures and 12 annexes. The investigation results are published in 18 scientific papers.
Investigation domain: Agricultural sciences The aim of the work takes into account some contribuitions concerning etiological agent spreading of the fire blight, main varieties of the apple, pear and quince trees resistence to the attack, and optimal ecological combatting products selection for outmost biological and economical efficiency of the applied treatments against this disease.
The work objectives reside in: determination of the spreading area and intensity of the fir e blight attack on rosaceae plants of the sead fruit growing cultures in the Republic of Moldova; main varieties of the apple, pear and quince trees susceptibility determination to the fire blight attack on the rosaceae; isolation, identification and biological specific features study of the phatogen agent of the rosacea fire blight Erwinia amylovora; biological efficciency determination of some biological agents on bacterium Erwinia amylovora; biological efficiency evaluation of some chemical products on bacterium Erwinia amylovora; economical efficacity determination of the applied treatments against rosacea fire blight.
Scientific novelty and originality. For the first time in the Republic of Moldova was determined the spreading areal and intensity attack of the fire blight of the rosacea sead fruit growing cultures; were selected the most susceptible varieties of the apple, pear and quince trees to natural infections with fire blight; the fire blight phytopathogen was identified by classic and modern methods application in conformity with EPPO PM 7/20 (2) Standard (symptom description, specific features of character manifestation on different culture media, structural properties, pathogenity tests on different plant organs, API 20E test, Gas Chromatography, DAS-ELISA, IF and PCR); were determined physiological and biochemical peculiarities of the bacterial isolates obtained from the samples of plants with symptoms; were determined biological effeciency of different copper formulations against Erwinia amylovora; was evaluated economical efficancy of the treatments applied against rosacea fire blight. Two strains of new bacteria (Pseudomonas fluorescens CNMN-PsB-04 and Pseudomonas aureofaciens CNMN-PsB-05) with antagonistic character to Erwinia amylovora for the first time were selected.
The scientific problem solved. Scientific substantiation of the antagonist strains capacities Pseudomonas fluorescens CNMN-PsB-04 and Bouillie Bordelaise (770 g/kg copper sulphate neutralized with calcium hydroxide) to inhibit phytopathogen E. amylovora, which allows their inclusion in the system for integrated protection of apple, pear and quince cultures, confirming the economic efficiency of the treatments.
Theoretical significance. Determination of the biological peculiarities of the phytopathogen E. amylovora in the Republic of Moldova, the efficient consumption norms and the optimal period for application of bacterial and chemical products on apple, pear and quince cultures for phytopathogen combating, as well.
Applicative value of the work. At least three methods among those investigated (growing on culture media, pathogenity tests, API 20E test, Gas-Chromatography, DAS-ELISA, IF and PCR) based on different biological principles, should be used to identify of the phytopathogen Erwinia amylovora. The antagonist strains of Pseudomonas sp. (P. fluorescens CNMN-PsB-04 of a bacterial suspension 109 cfu/ml and P. aureofaciens CNMN-PsB-05 of a bacterial suspension 107 cfu/ml) with a consumption norm of 5,0 l/ha and the chemical products Bouillie Bordelaise chemicals (770 g/kg of copper sulfate neutralized with Ca hydroxide) with a consumption norm of 10 kg/ha, bouillie bordelaise with a concentration of 1-2% can be included in the system for integrated protection of fruit growing cultures for rosaceae fire blight control. The bacterial strain P5, identified as Erwinia amylovora, is included in the collection of the pathogen microorganism of Phytopathology and Biotechnology Laboratory of the Institute of Genetics, Physiology and Plant Protection, being applied in diverse future investigations.
Implementation of the scientific results was effectuated in the farm „Exardiv Com” SRL.