Current Status and New Natural Hosts of Tomato yellow leaf curl virus (TYLCV) in Spain

Abstract

Tomato yellow leaf curl virus (TYLCV) is a major constraint to tomato production in Spain. This virus was observed for the first time in several tomato fields in Murcia (Spain) in the autumn of 1992 and Canary Islands in 1999. Currently the virus is prevalent along the Mediterranean coast of Spain (provinces of Málaga, Granada, Almería, Murcia, Alicante, Valencia, and Barcelona) and in the Canary Islands. Two viral species have been identified in Spain, TYLCV-Sar in 1992 and TYLCV-Is in 1997. TYLCV-Is is more severe than TYLCV-Sar and produces the greatest economic losses. Curling of leaflets, yellowing, and growth reduction are more pronounced in plants infected with TYLCV-Is than in those infected with TYLCV-Sar. In order to study the presence and behavior of both viral species in the affected area, over 1,320 tomato plants were sampled. DNA was extracted from the samples and analyzed by polymerase chain reaction (PCR) amplification. The degenerate primer pair for Begomovirus detection (AV494/AC1048) (2) was used to amplify the core region of the capsid protein gene. The amplified fragments were later analysed by restriction fragment length polymorphism (RFLP) with HaeIII enzyme to differentiate between TYLCV-Is and TYLCV-Sar species. The results showed that TYLCV-Sar (43.4%) and TYLCV-Is (56.6%) coexist in tomato crops and, in contrast with previous results (1), displacement of TYLCV-Sar for TYLCV-Is was observed. A search for the alternative hosts that may serve as virus reservoirs in areas where the virus is prevalent involved testing 210 samples of 95 species of weeds by PCR, with the same primers. The following species were found to be infected: Conyza sumatrensis (Retz.) E. Walker, Convolvulus sp., Cuscuta sp., Chenopodium murale L., Datura stramonium L., Dittrichia viscosa (L.) W. Greuter, Malva parviflora L., and Solanum nigrum L. This is the first reference of C. sumatrensis, Convolvulus sp., Cuscuta sp., and Ch. murale as natural hosts of TYLCV. These plants were symptomless. References: (1) S. Sanchez-Campos et al. Phytopathology 89:1038, 1999. (2) S. D. Wyatt et al. Phytopathology 86:1288, 1996.

Tomato yellow leaf curl virus Can Overwinter in Stellaria aquatica, a Winter-Hardy TYLCV-Reservoir Weed

“…Epidemiological sig nificance of weeds in TYLCV transmission is well known, and their role as a virus reservoir during crop-free periods has been docu mented in previous reports (8,23). Surveys for TYLCV weed hosts have been conducted by numerous researchers from different coun tries (2,(10)(11)(12)17,19,22,23) and identified in a wide range of poten tial hosts, most of which were symptomless. However, most of these studies focused on vims detection from field samples; only some have focused on whitefly transmission analyses.…”

“…), common bean (Phaseolus vulgaris), and eustoma (.Eustoma grandiflora) (1,3,14,15,20). A number o f weeds, including S. nigrum, Conyza sumatrensis, and Lamium amplexicaule, have been identified as TYLCV hosts (2,10,12,17). Furthermore, TYLCV has also been detected in many other weed species from families such as Amaranthaceae, Asclepiadaceae, Caparidaceae, Compositae, Cucurbitaceae, Euphorbiaceae, Leguminosae, Malvaceae, Nyctaginaceae, and Solanaceae (10.17,23).…”

Conyza sumatrensis(Retz.) E. H. Walker: A new record from Pakistan

“…C. sumatrensis tested positive for the Pepino mosaic virus in Spain (Có rdoba et al 2004) and was found to host the New record for Pakistan 1037 turnip mosaic virus in Zimbabwe (Chivasa et al 2002). It was also found to be infected with the yellow leaf curl virus in Spain (Jordá et al 2001). C. sumatrensis is a new addition to the flora of Pakistan.…”

Begomoviruses and Their Emerging Threats in South Korea: A Review

“…and Cuscuta sp. were recorded to be the reservoirs of TYLCV (Bedford et al, 1998;Jorda et al, 2001). In southern Spain, Sánchez-Campos et al (2000) found Datura stramonium, Mercurialis ambigua, Solanum nigrum, and S. luteum as an alternate host of TYLCV and concluded that these may all be involved in epidemics in other countries affected by TYLCV because these species frequently grow in many temperate regions worldwide.…”