(b) Serological: Plants showing mil

(b) Serological: Plants showing mild and no symptoms from
Azotobacter and Pseudomonas crude culture irrigation
treatment were selected for I-ELISA test (Table 3).
Controls were cucumber plants irrigated with distilled
water. Seven symptomless plants out of 11 and 4 out
of 8 gave negative I-ELISA values, for Azotobacter
and Pseudomonas, respectively.
(c) IC-RT-PCR: Plants which gave negative I-ELISA values
were subjected to IC-RT-PCR. All cucumber plants irrigated
with Azotobacter crude culture were found to be
virus-free, while 1 out of 4 plants irrigated with
Pseudomonas culture gave the band of CMV cp gene
(657 bp) but with a lower density compared with control
plants (Fig. 1).
(d) Electrophoresis: This was carried out on cucumber
plants giving negative I-ELISA and IC-RT-PCR results
(from Azotobacter and Pseudomonas crude culture irrigation
treatments), compared with untreated plants
which gave severe symptoms and healthy plants. Results
proved the presence of a pathogen related protein
(bands of about 30 KDa) which was not observed within
lanes of control plants (Fig. 2).
(e) Enzymes activity: The peroxidase and b-1,3-glucanase
activity tests were performed on cucumber plants treated
by irrigation with Azotobacter and Pseudomonas crude
cultures, in addition to untreated severely infected and
healthy plants. Results proved that Azotobacter treated
plants giving negative I-ELISA and IC-RT-PCR results
have the higher enzyme activity: 7 U/gm and 500 nktal/
gm, while Pseudomonas treated plants gave 4 U/gm and
350 nktal/gm for peroxidase and b-1,3-glucanase activities, respectively. Infected untreated plants gave
values of 1 U/gm and 250 nktal/gm, while no clear
enzyme activity was observed with healthy plants.
(f) Plant growth: Five cucumber plants giving different
symptom degrees from Azotobacter and Pseudomonas
crude culture irrigation treatments were left to grow to
60 days of age. Plants were then tested for dry weights
compared with infected and healthy controls. Data in
Table 4 revealed that Azotobacter treatment gave the
highest values followed by Pseudomonas treatment,
16.1 and 13.8 gm, respectively.
Statistical lowest significant difference test (LSD) showed
significant variations between Azotobacter and Pseudomonas
results.