Desempenho agronômico de videiras com e sem sintomas de viroses, e comparação molecular de isolados virais

Abstract

Resumo -O objetivo deste trabalho foi avaliar os efeitos de viroses em videiras sintomáticas e assintomáticas sobre as variáveis agronômicas relacionadas ao vigor das plantas e à qualidade enológica da uva, e comparar os isolados virais obtidos nessas duas condições. Realizaram-se dois experimentos com quatro cultivares. Todas as plantas foram indexadas, por meio da reação em cadeia da polimerase via transcrição reversa (RT-PCR) em tempo real, quanto à provável ocorrência dos seguintes vírus: Grapevine virus A (GVA), Grapevine virus B (GVB), Grapevine virus D (GVD), Grapevine leafroll-associated virus (GLRaV-1 ao -4, GLRaV-4 estirpe 5), Grapevine rupestris stem pitting-associated virus (GRSPaV) e Grapevine fleck virus (GFkV). As variáveis avaliadas foram: número de gemas brotadas e não brotadas, número de ramos com ou sem cachos, número total de gemas, número de cachos, massa de cachos frescos, massa total de bagas, massa do engaço, número de bagas por cacho, massa média de baga, sólidos solúveis totais, acidez total titulável, pH, massa de ramos podados ou diâmetros do tronco do porta-enxerto e da copa. Os efeitos negativos foram mais pronunciados nas plantas com sintomas de viroses; no entanto, constatou-se frequentemente que plantas sem sintomas também estavam infectadas. A análise molecular de GRSPaV, GVA e GLRaV-2, isolados de plantas sintomáticas e assintomáticas, resultou em alta percentagem de identidade de nucleotídeos entre isolados homólogos.Termos para indexação: Grapevine, Vitis, complexo do lenho rugoso, enrolamento-da-folha, PCR em tempo real. Agronomic performance of grapevines with and without virus symptoms, and molecular comparison of viral isolatesAbstract -The objective of this work was to evaluate the effect of viroses in symptomatic and asymptomatic grapevines on the agronomic variables related to the plant vigor and the enological quality of grapes, and to compare viral isolates obtained from these two conditions. Two experiments were performed with four cultivars. All plants were indexed by real time, reverse transcription-polymerase chain reaction (RT-PCR) for the probable occurrence of the following viruses: Grapevine virus A (GVA), Grapevine virus B (GVB), Grapevine virus D (GVD), Grapevine leafroll-associated virus (GLRaV-1 to -4, GLRaV-4 strain 5), Grapevine rupestris stem pitting-associated virus (GRSPaV), and Grapevine fleck virus (GFkV). The evaluated variables were: number of buds burst and not burst, number of branches with or without bunches, total number of buds, number of bunches, fresh bunch weight, total berry weight, rachis weight, number of berries per bunch, average berry weight, total soluble solids, total titratable acidity, pH, pruned branch weight, or rootstock and scion trunk diameters. The negative effects were more pronounced on the plants with virus symptoms; however, it was observed that plants without symptoms were also often infected. The molecular analysis of GRSPaV, GVA, and GLRaV-2, isolates from symptomatic and asymptomatic plants, resulted in a high perc...

Damage quantification in Physalis peruviana L. infected by the new putative sobemovirus physalis rugose mosaic virus

“…The reduction in yield contributing components such as fruit weight caused by viruses is widely reported in the literature (Fletcher et al 2000;Sevik and Arli-Sokmen 2012;Nascimento et al 2015;Thomas-Sharma et al 2018). Direct economic losses results from the reduction in fruit weight caused by PhyRMV infections.…”

Genetic diversity and identification of putative recombination events in grapevine rupestris stem pitting-associated virus

“…Furthermore, fruit quality is reduced by a change in berry characteristics such as pigment and sugar content. As a result, the acidity levels of wine produced are altered, decreasing the commercial value of crops (Barba et al, 2015;Basso et al, 2014;Martelli, 2014;Nascimento et al, 2015). The four main, most widespread virus-associated disease complexes responsible for economic loss are Grapevine fleck disease, Grapevine fanleaf degeneration disease, Grapevine leafroll disease and Rugose wood disease (Minafra et al, 2017).…”

“…Grapevine is the woody crop for which the largest number of intracellular pathogens have been reported (Martelli, 2014). More than 70 viruses have been identified, the majority of which are associated with disease complexes that hold the potential to cause a severe reduction in economic returns from crops (Barba et al, 2015;Basso et al, 2014;Martelli, 2017Martelli, , 2014Nascimento et al, 2015). Rugose wood disease is one of four major disease complexes responsible for economic losses.…”

“…Diseases associated with infection by these agents often result in a reduction in the productive lifespan of affected vineyards (Barba et al, 2015;Basso et al, 2014;Martelli, 2014;Nascimento et al, 2015).…”

Single berry sampling reveals novel insights into transcriptomic changes induced by leafroll virus infections in grapevine (V. vinifera)

“…Its vegetative propagation since several centuries has contributed to the worldwide spread of such pathogens and favored the emergence of complex diseases [2] and its perennial life cycle can cause the mixing of several pathogens in one single vine [3]. Virus associated diseases cause yield losses, reduced plant vigor, shorten the longevity of vines [4] and deteriorate berry and thus wine quality [5][6][7].…”