scholarly journals Recombination profiles between Tomato yellow leaf curl virus and Tomato yellow leaf curl Sardinia virus in laboratory and field conditions: evolutionary and taxonomic implications

2012 ◽  
Vol 93 (12) ◽  
pp. 2712-2717 ◽  
Author(s):  
Salvatore Davino ◽  
Laura Miozzi ◽  
Stefano Panno ◽  
Luis Rubio ◽  
Mario Davino ◽  
...  

Tomato yellow leaf curl Sardinia virus and Tomato yellow leaf curl virus have co-existed in Italian tomato crops since 2002 and have reached equilibrium, with plants hosting molecules of both species plus their recombinants being the most frequent case. Recombination events are studied in field samples, as well as in experimental co-infections, when recombinants were detected as early as 45 days following inoculation. In both conditions, recombination breakpoints were essentially absent in regions corresponding to ORFs V2, CP and C4, whereas density was highest in the 3′-terminal portion of ORF C3, next to the region where the two transcription units co-terminate. The vast majority of breakpoints were mapped at antisense ORFs, supporting speculation that the rolling-circle replication mechanism, and the existence of sense and antisense ORFs on the circular genome, may result in clashes between replication and transcription complexes.

2021 ◽  
Author(s):  
Wendy Marchant ◽  
Saurabh Gautam ◽  
Bhabesh Dutta ◽  
Rajagopalbab Srinivasan

Begomoviruses are whitefly-transmitted viruses that infect many agricultural crops. Numerous reports exist on individual host plants harboring two or more begomoviruses. Mixed infection allows recombination events to occur among begomoviruses. However, very few studies have examined mixed infection of different isolates/variants/strains of a Begomovirus species in hosts. In this study, the frequency of mixed infection of tomato yellow leaf curl virus (TYLCV) variants in field-grown tomato was evaluated. At least 60% of symptomatic field samples were infected with more than one TYLCV variant. These variants differed by a few nucleotides and amino acids resembling a quasispecies. Subsequently, in the greenhouse, single and mixed infection of two TYLCV variants (“variant #2” and “variant #4”) that shared 99.5% nucleotide identity and differed by a few amino acids was examined. Plant-virus variant-whitefly interactions including transmission of one and/or two variants, variants’ concentrations, competition between variants in inoculated tomato plants, and whitefly acquisition of one and/or two variants were assessed. Whiteflies transmitted both variants to tomato plants at similar frequencies; however, the accumulation of variant #4 was greater than variant#2 in tomato plants. Despite differences in variants’ accumulation in inoculated tomato plants, whiteflies acquired variant #2 and variant #4 at similar frequencies. Also, whiteflies acquired greater amounts of TYLCV from singly-infected plants than from mixed-infected plants. These results demonstrated that even highly similar TYLCV variants could differentially influence component (whitefly-variant-plant) interactions.


Plant Disease ◽  
2001 ◽  
Vol 85 (12) ◽  
pp. 1289-1289 ◽  
Author(s):  
F. Monci ◽  
J. Navas-Castillo ◽  
E. Moriones

Tomato yellow leaf curl virus (TYLCV, formerly TYLCV-Is) and Tomato yellow leaf curl Sardinia virus (TYLCSV, formerly TYLCV-Sar) are geminivirus species of the genus Begomovirus that cause the disease known as tomato yellow leaf curl. In Spain, TYLCV and TYLCSV have coexisted in field and greenhouse tomato (Lycopersicon esculentum) crops since 1996 (2). TYLCV is also the causal agent of the leaf crumple disease of common bean (Phaseolus vulgaris) (1), a species that TYLCSV is unable to infect (2). Analysis of field samples from common bean plants affected by leaf crumple disease collected in Almería (southeastern Spain) during 1999 showed that, unexpectedly, several samples hybridized with TYLCV- and TYLCSV-specific probes prepared to the intergenic region (IR) as previously described (1). Polymerase chain reactions (PCR) performed with total nucleic acids extracted from one of these samples (ES421/99) using primer pairs specific to the IR of TYLCV (MA-30/MA-31) or TYLCSV (MA-14/MA-15) (1) gave no amplification product. However, the combination of MA-30 (5′ end of TYLCV IR) and MA-15 (3′ end of TYLCSV IR) produced a PCR DNA product of the expected size (351 bp). Direct DNA sequencing of this product (GenBank Accession No. AF401478) indicated the presence of a chimeric IR in ES421/99. Comparison of the obtained sequence with those available for isolates reported from Spain showed that the 5′ side (149 nt) from the stem-loop structure conserved in the IR of all geminiviruses was 99% identical to the corresponding region of TYLCV (GenBank Accession No. AF071228) and only 62% identical to TYLCSV (GenBank Accession No. Z25751). In contrast, the 3′ side (124 nt) from the stem-loop was 98% identical to the corresponding region of TYLCSV and only 57% identical to TYLCV. The 33-nt region involved in the stem-loop was 100% identical to TYLCV and showed one nucleotide change in the loop with respect to TYLCSV. Therefore, this DNA sequence data showed evidence of the occurrence in ES421/99 of a natural recombination between TYLCV and TYLCSV. The biological and epidemiological consequences of the presence of this new interspecific recombinant have yet to be determined. References: (1) J. Navas-Castillo et al. Plant Dis. 83:29, 1999. (2) S. Sánchez-Campos et al. Phytopathology 89:1038, 1999.


EPPO Bulletin ◽  
2002 ◽  
Vol 32 (1) ◽  
pp. 31-35
Author(s):  
A. F. Arsenio ◽  
E. Neto ◽  
N. Ramos ◽  
S. Mangerico ◽  
E. Fortunato ◽  
...  

2020 ◽  
pp. 30-34
Author(s):  
С.Ф. Гавриш ◽  
Т.А. Редичкина ◽  
А.В. Буц ◽  
Г.М. Артемьева

Дана информация об изучении коллекции гибридов F1томата (Solanum lycopersicum L.) зарубежной селекции различных фирм-оригинаторов, рекомендованных производителями семян как толерантные к вирусу желтой курчавости листьев томата. Все гибриды обладали комплексом хозяйственно ценных признаков и набором генов устойчивости к основным заболеваниям томата, в том числе к новому для юга России опасному патогену с максимальным потенциальным риском – вирусу желтой курчавости листьев томата (Tomato yellow leaf curl virus — TYLCV). Исследования проведены в 2017-2018 годах в лаборатории пасленовых культур ООО «НИИСОК» и в лаборатории молекулярной диагностики растений ООО «Семеновод». Всего было протестировано 34 гибрида F1 томата. Гибриды оценивали по совокупности хозяйственно ценных признаков, также проводили молекулярно-генетический анализ на наличие и аллельное состояние основных генов устойчивости: к вирусу табачной мозаики (Tm2а), фузариозному увяданию (I2), вертициллезному увяданию (Ve), к кладоспориозу (Cf9), нематодам (Mi1.2), вирусу бронзовости томата (Sw5), вирусу желтой курчавости листьев томата (Ty3a). Установлено, что все проанализированные гибриды томата с заявленной оригинаторами семян устойчивостью к вирусу желтой курчавости листьев были гетерозиготны по гену Ty3a. На основании проведенных исследований и с учетом требований рынка разработаны модели гибридов F1 томата юга России. Перспективный гибрид томата должен обладать индетерминантным типом роста с укороченными междоузлиями (4,5-5 см) а также хорошей облиственностью. Плоды томата должны быть с красной равномерной окраской без зеленого пятна у плодоножки, с плоскоокруглой или округлой формой плода и со средней массой 220-270 г. Для повышения транспортабельности томатов необходимо, чтобы плоды отличались высокой прочностью и характеризовались хорошей лежкостью. Урожайность гибрида томата должна быть более 30 кг/м2, а товарность - не менее 85%. Гибрид томата должен обладать следующим набором генов устойчивости в гетерозиготном состоянии: Ty3a, Mi1.2, Cf-9, а также в гомозиготном состоянии: Tm2a, I2, Ve. The article provides information on the study of the collection of F1 tomato hybrids (Solanum lycopersicumL.) of foreign breeding from various firms-originators recommended for cultivation in regions with a strong spread of tomato yellow leaf curl virus. All hybrids had a complex of economically valuable traits and a set of genes for resistance to the main diseases of tomato, including a new dangerous pathogen for the South of Russia with a maximum potential risk — the tomato yellow leaf curl virus (TYLCV). The studies were carried out in 2017-2018 in the Solanaceae Laboratory of LLC NIISOK and in the Molecular Diagnostics Laboratory of Plants of LLC Semenovod. A total of 34 F1 tomato hybrids were tested. The hybrids were assessed by a set of economically valuable traits. Molecular genetic analysis was also carried out for the presence and allelic state of the main resistance genes: Tomato mosaic virus (Tm2a), Fusarium wilt (I2), Werticillium wilt (Ve), Cladosporium fulvum (Cf9), Nematodes (Mi1.2), Tomato spotted wilt virus (Sw5), Tomato yellow leaf curl virus (Ty3a). It was found that all the analyzed tomato hybrids with the declared by seed originators resistance to yellow leaf curl virus were heterozygous for the Ty3a gene. Based on the conducted research and taking into account the market requirements, models of F1 tomato hybrids for protected ground for the South of Russia have been developed. A promising tomato hybrid should have an indeterminate growth type with shortened internodes (4.5-5 cm) and good foliage. Tomato fruits should have a uniform red color without green shoulders, with a flat-round or round shape of the fruit and with an average weight of 220-270 g. To increase the transportability of tomatoes, it is necessary that the fruits are highly firm and characterized by good shelf life. The yield of tomato hybrid should be more than 30 kg/m2, and marketability should be at least 85%. The tomato hybrid should have the following set of resistance genes in a heterozygous state: Ty3a, Mi1.2, Cf-9, and also in a homozygous state: Tm2a, I2, Ve.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Adi Moshe ◽  
Eduard Belausov ◽  
Annette Niehl ◽  
Manfred Heinlein ◽  
Henryk Czosnek ◽  
...  

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Nathalie Becker ◽  
Loup Rimbaud ◽  
Frédéric Chiroleu ◽  
Bernard Reynaud ◽  
Gaël Thébaud ◽  
...  

2014 ◽  
Vol 165 (4) ◽  
pp. 1684-1697 ◽  
Author(s):  
Dagan Sade ◽  
Nir Sade ◽  
Oz Shriki ◽  
Stephen Lerner ◽  
Alem Gebremedhin ◽  
...  

Fitoterapia ◽  
2021 ◽  
pp. 104989
Author(s):  
Ning-Dong Zhao ◽  
Yu-Lin Li ◽  
Yu Song ◽  
Bao-Jia Yang ◽  
Xiao Ding ◽  
...  

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