استحثاث المقاومة الجهازية في نبات الخيار (.Cucumis sativus L)‎ ضد فايروس موزائيك الخيارCMV باستخدام بعض أنواع العوامل الحيوية البكتيرية

Abstract EN

This study was conducted to determine the ability of inducing systemic resistance in cucumber plants against cucumber mosaic virus (CMV) by using three genus of bacteria Bacillussubtilis , Pseudomonas fluorescens and Azotobacter chroococcum and determine the activity of each one individually and as a mixture to control the virusThe plastic pots experiment included five treatments as they are 1- Immerse cucumber seeds in Bacillus subtilis suspension 2×109 CFU, Pseudomonas fluorescens suspension 5×1010 CFUand Azotobacter chroococcum suspension 2×1010 CFU individually and as a mixture of two genus for 30 and 60 min.

, 2- Treatment of Irrigate cucumber plants 2 days before treatment with CMV with above bacteria suspension individually and as a mixture 3- immerse cucumber seeds in Bacillus subtilis suspension 2×109 CFU, Pseudomonas fluorescens suspension 5×1010 CFU and Azotobacter chroococcum suspension 2×1010 CFUfor 30 and 60 min.

, then Irrigate cucumber plants 2 days before treatment with CMV with the same bacteria suspension individually and as a mixture 4-Infected control treatment.

5-control treatment .

The evaluation of treatment were estimated depending upon the infection percentage , infection severity percentage and determination of some growth parameters .The immerse of seeds by the above three genus of bacteria individually and as a mixture for 30 and 60 min.

, showed significant reduction in percentage of infection and severity , which was ranged between 17.0 -55.5 % and 11.1 – 26.6 % respectively , compared to infected control treatment which was percentage of infection 100% and the severity 88.83 % respectively .

Significant increase in growth parameters were appeared in comparison to the control treatments .

The treatment of immersing seeds in mixed bacteria over –powered upon other treatments individually through 30 and 60 min.

, in the percentage of infection and disease severity and in case of increase growth parameters .The mixture of Bacillus subtilis and Azotobacter chroococcum for 30 and 60 min.

without treatment with virus over-powered upon other treatment in : the length of vegetative growth was 52.0 and 53.5 cm , the length of roots which was 46.1-54.5 cm , fresh weight of vegetative parts which was 23.0 and 24.1 gm.

, the fresh weight of roots which was 10.7 and 11.5 gm.

, dry weight of roots was 1.7 and 2.5 gm.

respectively.

The irrigation treatment lead to clear decrease in percentage and severity of infection and improve the plant growth parameters in comparison to infected control .The treatment of mixed bacteria over-powered in the individual bacteria treatment in term of reduction in percentage and severity of infection ,and plant growth parameters the incidence of infection was ranged between 17.0 -27.8 % while severity infection 8.9 -17.8 % compared to infected control 100% incidence infection with 88.8 % severity infection .

The treatment of immersing cucumber seeds for 30 and 60 min.

, then irrigated by three genus of the above suspension bacteria individually or as mixture gave protection to cucumber plants against CMV through reduction in the infection percentage and its severity.There was significant differences between using the mixed bacteria followed by irrigation of the same mixture or using the three genus of bacteria individually for two periods (30 and 60 min.) , the percentage of infection in the mixture was 17.0- 26.8 % and the infection severity was 11.1-20.0 % , while the infection percentage was 30.5-43.7 % and the infection severity was 22.2-31.3 % in the individual bacteria treatment, compared to infection percentage 100% of infected control and the infection severity was 95.5% respectively .