Results and discussion. In total, 93 samples of plant materials with symptoms of bacterial
diseases were collected in such localities as Khromtau (3 samples), Khromtau district, Kargaly village
(3 samples), «AkTep» LLP (1 sample), Shamshi Kaldayakova village, Kargalinsky district, «Aktobe
agricultural experimental station» (4 samples), Aktobe, Aktobe region; the village of Zarechnoye
(19 samples), Kostanay district, Kostanay region; Nauchnoye village (30 samples), Shortandinsky
district, Akmola region; village Konstantinovka (5 samples), Arshalyn district, LLP «Baimyrza-
AGRO» (2 samples), Village Birsuat, District Birzhan Sal, Akmola region, Pavlodar city (11 samples),
Pavlodar region, LLP «Naidorovkoe» (4 samples), Village Akpan, Osakarovsky district, Karaganda
region, «Astra-Agro LTD» LLP (11 samples), Koksun village, Abay district, Karaganda region.
Thus, out of 93 plant DNA samples with symptoms of bacterial diseases in cereal crops,
120 samples were isolated in the west and north of Kazakhstan. Molecular screening of causative
agents of bacterial diseases using specific genetic markers showed the presence of causative agents of
basal and black bacteriosis and their pathovars in the northern region of Kazakhstan. Bacterioses
infecting cereals were identified by the ITS region sequences. The causative agent of basal bacteriosis
(Pseudomonas syringae) was identified in samples from the Karaganda, Kostanay, and Akmola
regions, which is confirmed by the results of sequencing of the species-specific region of the genome
of this bacterium.
PCR screening was carried out to identify causative agents of bacterial diseases of cereals
using specific DNA markers. The causative agent of basal bacteriosis (Pseudomonas syringae) was
identified in samples from the Karaganda region, which is confirmed by the results of sequencing of
the species-specific genome region of this bacterium. Molecular screening of causative agents of
bacterial diseases using specific markers also showed the presence of causative agents of basal
bacteriosis and their pathovars in the western and northern regions of Kazakhstan.
During the work, the optimal parameters of the amplification steps were also established: 94°C
for 10 min (initial denaturation), then 35 three-step cycles (94°C for 30 s, 54°C for 30 s, 72°C for
1 min), and final elongation at 72°C for 5 minutes.
Interpretation of the screening results was carried out based on a visual assessment of the
agarose gel by the presence or absence of specific bands of amplified DNA on the electropherogram,
as well as by comparing the mobility in the gel of PCR fragments of samples (the sizes of PCR
fragments are given in Table 2).
Figures 1-6 show examples of screening results for the 16S rRNA, rpoD, gyrB, fyuA, and gltA
marker genes using standard PCR and electrophoresis in 1.5% agarose gel with 1×TAE buffer at
|