Genetic diversity, host range, and distribution of tomato yellow leaf curl virus in Iran

Abstract

Summary. -Tomato yellow leaf curl virus (TYLCV) is considered one of the most important tomato pathogens in tropical and subtropical regions including Iran. During the years 2007 to 2009, a total number of 510 symptomatic and asymptomatic vegetable, ornamental and weed samples were collected from fields and greenhouses in ten provinces of Iran. Symptoms included stunting, yellowing, leaf curl and flower senescence. PCR with specific primers showed TYLCV infection in 184 samples (36%) such as cucumber, pepper, tomato and several weeds from seven provinces. Based on the geographical origin, host range and symptoms, twenty three representative isolates were selected for phylogenetic analysis. An amplicon with a size about 608 base pair (bp) comprising partial sequence of the coat (CP) and movement protein (MP) coding regions of the viral genome was sequenced and compared with the corresponding selected sequences available in GenBank for Iran and worldwide. Phylogenetic analyses on the basis of the nucleotide sequences indicated two geographically separated clades. Isolates collected from Hormozgan, Khuzestan and Kerman provinces were grouped together with other Iranian isolates including TYLCV-Ir2, TYLCV-Kahnooj, and an isolate from Oman. It was also revealed that isolates collected from Boushehr, Fars, Tehran, and Isfahan placed close to the Iranian isolate TYLCV-Abadeh and isolates from Israel and Egypt. No correlation was found between the genetic variation and the host species, but selected Iranian isolates were grouped on the basis of the geographical origins. Results of this study indicated a high genetic diversity among Iranian TYLCV isolates.

Natural Occurrence of Tomato leaf curl New Delhi virus in Iranian Cucurbit Crops

“…These viruses have become a main constraint on crop production all through the world due to the worldwide increase in their population and distribution of insect vectors, and movement of plant material globally ( Seal et al, 2006 ). In the present work, the main vegetable producing areas in Khuzestan and Tehran provinces of Iran were surveyed in the period of 2012–2014 for the presence of TYLCV and the virus was found to be widespread in these regions, similar observations have been reported previously ( Bananej et al, 2009 ; Shirazi et al, 2014 ); this may reflect both a very high inoculum reservoir and the prevalence and efficiency of its whitefly vectors. This study also reports the natural occurrence of TYLCV on alfalfa, pepper and spinach plants for the first time in Iran; these hosts may play an important role in the spread of the virus in these regions.…”

Monitoring the occurrence of tomato bacterial spot and range of the causal agent Xanthomonas perforans in Iran

“…In parallel to the growing trend in tomato cultivation, risks of crop losses due to biotic stresses have also increased over the years. Several fungal and viral diseases such as alternaria leaf spot, fusarium and verticillium vascular wilts (Amini, ), and Tomato yellow leaf curl virus (Shirazi et al ., ), have been reported to affect tomato production in the country. In contrast, no reports of economic losses due to bacterial diseases of tomato are available from Iran.…”

Molecular validation for impossible transmission of TYLCV through mechanical route

“…In Egypt, the incidence of infection is very high, with visual estimates of TYLCV infection reaching 100 % in some areas [12]. TYLCV epidemiology in key tomato growing areas of Iran, notably in the central and southern regions, was found to be 36%, while it was found to be 89 % in tomato fields in Saudi Arabia, which borders Iran's southern region [13]. The unexpected TYLCV outbreak in these areas could be attributed to warm weather conditions that promote vector activity, virus replication, or host susceptibility.…”

“…The unexpected TYLCV outbreak in these areas could be attributed to warm weather conditions that promote vector activity, virus replication, or host susceptibility. It has recently been revealed that The Mediterranean region and the Middle East are the key starting points for worldwide TYLCV movements [13]. Stunting, leaf curving upward, chlorosis, reduced leaf size, flower abortion, stem erect, limited plant growth and loss in tomato production are typical symptoms of TYLCV infection.…”