198 CUPRINS

CGGTGTGTA3′ [3]. PCR conditions were adjusted according to William et al. [18].
Ampli ed 16S rRNA gene fragments were excised from the gel and directly cloned
into pGEM-T Easy cloning vector (Promega). Ligation mixture was transformed into
E. coli JM 101 strain. After ampli cation, plasmid DNA samples of each isolates
were digested by restriction enzymes and sequenced. The sequences obtained were
used to perform BLAST searches using the NCBI GenBank database. Comparison of
approximately 1,400 bp fragments of 16S rRNA gene sequences of each isolates with
other 16S rRNA sequences in the NCBI GenBank database were performed.
Results and Discussion
Although there have been a number of chemical, mechanical and biological studies
for prevalence of Erwinia amylovora, studies connected with the bacterial ora of
Byctiscus betulae L. leaf-rolling weevils from the Republic of Moldova have been
neglected. In the present study, four different bacteria, non-spore-forming (Bb1, Bb2,
Bb3, Bb4) were isolated from B. betulae. These bacteria were selected and characterized
by morphological, physiological and biochemical properties (Tables 1, 2, 3).
№
Isolate
number
Table 1. The morphological characteristics of bacterial isolates
Color and of
colonies
1. Bb1 Cream
2. Bb2 Cream
3. Bb3 Cream
4. Bb4 Yellow
№
Shape of
colonies
Smooth,
round
Smooth,
round
Smooth,
round
Smooth,
round
Morphological characteristics
Gram stain
Shape of
bacteria
Turbidity
when grown
in NB
Gram - Bacillus Turbid
Gram - Bacillus Turbid
Gram - Bacillus Turbid
Gram - Bacillus Turbid
Table 2. The physiological characteristics of the bacterial isolates
Morphological characteristics
Isolate number
Bb1 Bb2 Bb3 Bb4
1. Growth in 5% NaCl 1,75 1,72 1,75 1,76
2. Growth in 6% NaCl 1,77 1,74 1,64 1,70
3. Growth in 7% NaCl 1,77 1,76 1,75 1,75
4. Growth in 8% NaCl 1,88 1,84 1,88 1,81
5. Growth in 9% NaCl 1,69 1,71 1,74 1,89
Four isolates from pears and apples pests Byctiscus betulae L. with re blight
symptoms from the Republic of Moldova were analysed for their relationship to E.
amylovora. Several classical methods including growth on semiselective media,
pathogenicity tests and PCR were used in this study. All isolates as well as the E.
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