Studing the effect of Cucumber mosaic virus infection on the structural and physiological changes of the pepper plant and its effect on plant development and productivity

2019/2020 growing season in the autumn and spring cultivation loops to investigatethe effect Cucumber mosaic virus (CMV) infection on the vegetative growthindicators (apparent symptoms, number of leaves, number of branches, height Plant,leaf area), yield (fruit weight and number of fruits) and physiological indicators (plantpigment production, proline production and hydrogen peroxide production) for fourhybrids of pepper plants (Taline F1, Amani F1, Harek F1, Marvilo F1) at three dates(15, 30 and 45 days) after inoculation with CMV . histological and anatomical studywas conducted for the leaves of the mentioned hybrids 30 days after infection with thevirus. The experiment was carried out by using complete randomized block designwith 8 treatments and 4 replicates per treatment. The results of the autumn and springloops showed that the symptoms of CMV infection appeared on all the hybrids ofpepper infected with the virus, and the severity of symptoms varied on the hybridsafter 15, 30, 45 days of infection. CMV infection 15 days after infection affectedvegetative growth indicators (apparent symptoms, number of leaves, number ofbranches, plant height and leaf area) and productivity. The greatest effect of infectionwith the virus was after 30 days of infection, where the values of the studiedvegetative growth indicators and productivity decreased in the pepper hybrids infectedwith the virus with great significant differences compared to the control plants. After45 days of infection with the virus, the effect of viral infection decreased with the ageof the plant. CMV infection affected the relative water content % and photosyntheticpigments (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids) after 15days of infection with the virus and The greatest effect of infection with the virus wasafter 30 days of infection, where the values of the relative water content andphotosynthetic pigments decreased in the pepper hybrids infected with the virus withgreat significant differences compared to the control plants, After 45 days of infectionwith the virus, the effect of viral infection decreased with the age of the plant. On thethree dates, the decrease in chlorophyll A values was greater than the decrease in thevalues of chlorophyll B and carotenoids, and the decrease in chlorophyll B values wasgreater than the decrease in carotenoid values, The decrease in the values ofphotosynthetic pigments led to a decrease in the photosynthesis process. The resultsshowed that the infection with CMV affected the content of proline and hydrogenperoxide after 15 days of infection with the virus, and the greatest effect of infectionwith the virus was after 30 days of infection, where the values of proline andhydrogen peroxide increased in the hybrids of pepper infected with the virus withgreat significant differences compared to the control plants, After 45 days of infectionwith the virus, the effect of viral infection decreased with the age of the plant. On thethree dates, the effect of CMV infection on all studied indicators in the spring loopwas greater than the effect on them in the autumn loop, and the sweet hybrids showedmore resistance to infection with the virus than the hot hybrids. Infection with CMVled to a decrease in sugars, proteins and lipids in the leaves of plants infected with thevirus, where the cells appeared under the light microscope after 30 days of infectionwith the virus in pale colors compared to the leaves of the control plants in which thecells were more colored, so the coloration was more intense and clearer, as a result ofthe occurrence of sabotage in the cellular content of infected leaves compared toleaves of control plants. And the epidermis appeared in the leaves of the plants of thecontrol by examining under the light microscope smooth and the stomata in a healthyposition. As for the affected epidermis, wrinkles were observed, which is one of theapparent symptoms of infection with CMV. These wrinkles led to closing the stomataand thus resulted in the poor supply of the plant with carbon dioxide CO2 and this ledto A disturbance in the photosynthesisprocess