تأثير سلالتين من بكتيريا الجذور المحفزة للنمو في نسبة و شدة الإصابة بفيروس تجعد و اصفرار أوراق البندورة-الطماطم و في بعض مؤشرات النمو لنبات البندورة-الطماطم تحت ظروف البيوت المحمية

Abstract EN

This study was conducted to evaluate the efficiency of two strains of plant growth promoting bacteria Pseudomonas ch/ororaphis MA342 (MA), and B.

subti//is FZB27 (B27), in reducing infection rate and severity of infection with Tomato yellow leaf cur/ virus on tomato plants, in addition to its effects on peroxidase enzyme activity, and some growth parameters of tomato plants.

The experiment was conducted at the Agricultural Scientific Research Center in Lattakia during the 2018/2019 growing season.

Bacteria were applied by seed treatment and root irrigation.

Results indicated that the two bacterial strains caused reduction in virus infection rate, 15-30 days after inoculation with the virus, compared with the healthy control.

The two bacterial strains caused similar reduction (33.34%) in infection rate 15 days after virus inoculation, with higher reduction with F27 strains (16.67%) at 30 days after inoculation.

Also the two bacterial strains reduced the severity of viral infection, and the highest reduction was with strain B27 (39.23%) compared with strain MA (24.73%), 15 days after virus inoculation.

The two bacterial strains increased the activity of the peroxidase enzyme in treated plants, compared with the untreated.

The highest increase in peroxidase enzyme activity was with B27 strain (39.13%) 15 days after virus inoculation.

However, at 30 days after virus inoculation, treatment with the bacterial strain MA led to a significant increase in peroxidase enzyme activity of 204.34% obtained.by the MA strain.

The two strains used in this study increased the growth parameters in treated plants, compared with the untreated plants.

With bacterial strain MA treatment, there was an increase in plant height, foliage dry weight, root fresh weight, and root dry weight of 39.12%.

47.26%.

18.42% and 33.64%, respectively, compared with the control treatment.

Similarly, with the bacterial strain B27 treatment, an increase in foliage fresh weight and fruit weight of 42.31% and 83.79% was obtained, respectively, compared with the healthy control.