Tomato yellow leaf curl virus in Tomato Crop of Khyber Pakhtunkhwa Province: Virus and Vector Prevalence and Transmission Properties
Tomato yellow leaf curl virus in Tomato Crop of Khyber Pakhtunkhwa Province: Virus and Vector Prevalence and Transmission Properties
Ghufran ul Haq1*, Muhammad Arif2, Asad Ali2 and Mian Inayatullah3
ABSTRACT
The present study was conducted to determine the prevalence of Tomato yellow leaf curl virus (TYLCV) and the population of its vector, whiteflies (Bemisia tabaci), and determine the transmission properties of the prevalent isolate of the virus in the major tomato growing areas of Khyber Pakhtunkhwa (KP). For this purpose, surveys were conducted in the hilly areas of Mohmand Agency and Malakand Agency and plains of Shabqadar, Charsadda and Peshawar during 2011, 2012 and 2013, to determine the incidence of TYLCV and the population of its vector. Triple antibody sandwich-enzyme linked immunosorbent assay (TAS-ELISA) was successful in detecting TYLCV in naturally and whiteflies inoculated tomato plants. Transmission properties of the virus were determined by inoculation of tomato plants of susceptible cultivar, Roma-VF, by whiteflies, determining the minimum time required for acquisition and inoculation of the virus, latency period and the persistence capacity. The highest incidence of 9.47 percent of TYLCV was recorded in Mohmand Agency, followed by Malakand Agency with 8.2 percent, Shabqadar with 7.7 percent, Charsadda with 4.9 and Peshawar with 5.8 percent. The average whiteflies population was the highest, 22.13, in Mohmand Agency, followed by Malakand Agency with 18.5, Shabqadar with 15.6, Charsadda with 14.9 and Peshawar with 14.2. A positive correlation was found between the whiteflies population and the viral incidence. Studies on the transmission properties of TYLCV revealed that, given an acquisition access peiod (AAP) of 48 hours, a single viruliferous whitefly had the capacity to transmit the virus, but for 100 percent transmission a minimum of five whiteflies per seedling were required. The minimum requirement of AAP was 30 minutes, which was longer than inoculation access period (IAP) of 20 minutes. For 100 percent acquisition and transmission, a minimum of 10 hours was required. The latent period was five to seven hours. The virus persisted in its vector, Bemisia tabaci, upto 10 days after which the whiteflies were dead, indicating a persistent type of transmission. The viral incidence and whiteflies population were higher in the cooler hilly areas than the plains and the values for the transmission parameters were different from those reported elsewhere in the world
To share on other social networks, click on any share button. What are these?
