Varietal Reaction of Cucumber against <i>Cucumber mosaic virus</i>

Abstract

Family Cucurbitaceae is primarily found in the warmer regions of the world. It is the major family for economically important species, particularly edible fruits. In Pakistan cucurbits occupies an area of 28,600 ha with a very low production in Khyber Pukhtunkhwa due to many biotic and abiotic stresses. The reason is also the lack of growers' awareness about the diseases and the cultural practices adopted to provide favorable environment for development of epidemics. Viral diseases such as Cucumber mosaic virus (CMV) cause losses as high as 100%. Various control strategies are being used to control CMV. The aim of the current study was to screen out different verities and to find the most resistant one against CMV. CMV isolate was collected from farmer's field at the site of TaruJaba during a survey of cucurbit crops. The identity of the virus was confirmed through DAS-ELISA using diagnostic kit (ADGEN, UK). Seventeen cucumber germplasm seeds were sown in earthen pots in which fourteen were germinated and exhibited characteristics symptoms of the virus while none of them showed resistance against CMV. Symptoms' expression was delayed in summer green and local green till 12 days post inoculation. While in khyber, Diamond, VEGAF1 and Yousaf, symptoms started to appear soon after inoculation categorizing them as highly susceptible. No resistance is found in available commercial germplasm, so more germplasm from different area of Pakistan should be tested for resistance against CMV. If no resistance is found locally imported, germplasm can be evaluated for a source of resistance against the prevalent isolates of CMV.

Prevalence, mechanical transmission and impact of environmental conditions on cucumber mosaic disease in Sindh

“…The disease incidence percentage was calculated by dividing number of cucumber plants showing mosaic symptoms with total number of plants examined for the disease. Severity of the disease was measured by using 1-5 rating scale [4]. Mechanical transmission of CMV was done on Chenopodium amaranticolor by rubbing the extract on wounded leaves.…”

“…Carborundum powder was used to provide tiny wounds for entry of the virus particles in the leaf tissues, then leaves were inoculated with prepared sap. After inoculation leaves tap water was applied to remove excess sap on wounds and plants were shifted in dark for symptoms development as described by [4]. Plants were kept under observation until the symptom inducement.…”

“…Such features are considered to be key factors for the virus epidemics in host plants. CMV may cause up to 100% losses in susceptible host plant under favourable environmental conditions [4]. The CMV's extensive host rang contains several species of crops, which play a role as a source of CMV, also for the spreading of virus the various crops.…”

“…Additionally, there is highly specification among isolates and aphid species to transmit the virus [8,9]. The virus is also sap/mechanical transmissible to the host or indicator plants [4,10,11]. The plants which are parasitic such as dodder (Cuscuta spp.)…”

Genetic Diversity of Cucumber Mosaic Virus from Catharanthus roseus, Jasminum sambac, Patchouly, Cubeb and Java-tea

“…Kerugian ekonomi akibat CMV telah banyak dilaporkan dari berbagai negara. Virus ini menyebabkan kerugian hingga 100 % pada tanaman Cucurbitaceae di Pakistan (Akbar et al 2015). Epidemi CMV di Amerika Serikat bagian Timur dan midwest sangat memengaruhi produksi snap bean (Phaseoulus vulgaris L.) (Nouri et al 2014).…”