Rootstock Effects on Fruit Yield and Quality of 'BRS Tainá' Seedless Table Grape in Semi-Arid Tropical Conditions.

In viticulture, choosing the most suitable rootstock for a specific scion cultivar is an efficient and cost-effective way to increase yield and enhance the physicochemical characteristics of the fruit. The objective of this study was to evaluate the agronomic performance of the 'BRS Tainá' grapevine on different rootstocks under the conditions of the Sub-Middle São Francisco Valley. The main experimental factor consisted of eight rootstocks (IAC 313, IAC 572, IAC 766, 101-14 MgT, Paulsen 1103, Ramsey, SO4, and Teleki 5C), arranged in randomized blocks with four replicates. The experiment was conducted over four production cycles, from 2021 to 2023, in a commercial crop area in Petrolina, PE, Brazil. There were significant effects of rootstocks for the yield and number of bunches per plant, as well as berry length and firmness. 'BRS Tainá' achieved the highest yield (22.2 kg per plant) when grafted onto the Paulsen 1103 rootstock, which was superior to the yield on 101-14 MgT, IAC 313, and IAC 572 rootstocks. The highest number of bunches (88) was obtained with 'BRS Tainá' grafted on Paulsen 1103, while the lowest number (63) was obtained on IAC 572; both these rootstocks were not significantly different from the other rootstocks. For all scion-rootstock combinations, the mean values for soluble solid (SS) content, titratable acidity (TA), and the SS/TA ratio were similar to those previously described for 'BRS Tainá', meeting the commercialization standard. The results for the yield and number of bunches per plant indicate the suitability of grafting 'BRS Tainá' on Paulsen 1103 under the semi-arid tropical conditions of the São Francisco Valley.

A Conservative Mutant Version of the Mrr1 Transcription Factor Correlates with Reduced Sensitivity to Fludioxonil in Botrytis cinerea.

Fludioxonil is a highly effective phenylpyrrole fungicide for controlling Botrytis cinerea. Although the field efficacy of fludioxonil remains high, Botrytis cinerea isolates with reduced sensitivity have been reported globally. The molecular target of fludioxonil still remains unknown; however, a mechanism of reduced sensitivity to fludioxonil underlies the overexpression of the ATP binding cassette (ABC) transporter AtrB in a dependent pathway of the Mrr1 transcription factor. Fludioxonil is a key player in controlling B. cinerea infection in table grapes in Chile. However, some isolates with a reduced sensitivity to fludioxonil were detected. This study observed endogenous atrB overexpression in Chilean isolates with reduced sensitivity to fludioxonil (n = 22) compared to the sensitive isolates (n = 10). All isolates increased the expression of atrB in a growth medium supplemented with fludioxonil (0.05 µg/mL). However, sensitive isolates showed lower atrB expression than those with reduced fludioxonil sensitivity. Remarkably, a mutant version of the transcription factor Mrr1 carrying 21 amino acid modifications was identified in all isolates with reduced sensitivity to fludioxonil. These changes alter the protein's transcription factor domain and the C-terminal portion of the protein but not the Zn (2)-C6 fungal-type DNA-binding domain. These results suggest a direct relationship between the conserved and divergent mutant version of mrr1 and sensitivity to fludioxonil. This study provides a new target for developing molecular diagnostic strategies to monitor B. cinerea's sensitivity to fludioxonil in the field.

Volatile Organic Compounds (VOCs) Produced by Gluconobacter cerinus and Hanseniaspora osmophila Displaying Control Effect against Table Grape-Rot Pathogens.

Table grapes (Vitis vinifera) are affected by botrytis bunch rot and summer bunch rot, the latter a complex disease caused by Botrytis cinerea, Aspergillus spp., Penicillium expansum and Rhizopus stolonifer. To search for biocontrol alternatives, a new bioproduct composed of Gluconobacter cerinus and Hanseniaspora osmophila, a consortium called PUCV-VBL, was developed for the control of fungal rots in table grapes. Since this consortium presents new biocontrol species, the effect of their VOCs (volatile organic compounds) was evaluated under in vitro and in vivo conditions. The VOCs produced by the PUCV-VBL consortium showed the highest mycelial inhibition against Botrytis cinerea (86%). Furthermore, H. osmophila was able to inhibit sporulation of A. tubingensis and P. expansum. VOCs' effect in vivo was evaluated using berries from Red Globe, Thompson Seedless and Crimson Seedless grapes cultivars, demonstrating a mycelial inhibition by VOCs greater than 70% for all evaluated fungal species. The VOC identification of the PUCV-VBL consortium was analyzed by solid-phase microextraction coupled to gas chromatography-mass spectrometry (SPME-GCMS). A total 26 compounds were identified, including 1-butanol 3-methyl, propanoic acid ethyl ester, ethyl acetate, phenylethyl alcohol, isobutyl acetate and hexanoic acid ethyl ester. Our results show that VOCs are an important mode of action of the PUCV-VBL biological consortium.

Biology and Population Dynamics of the American Vine Moth and the Potential Biocontrol with Trichogramma pretiosum.

The American grapevine moth (AGVM), Lasiothyris luminosa (Razowski & Becker) (Lepidoptera: Tortricidae), was recently registered as a new pest for table grapes in the Northeast region of Brazil. In the present study, two approaches were made aiming to aid information to support management strategies for the new pest control: (i) study AGVM biology in the laboratory and its population dynamics in the field and (ii) evaluate Trichogramma pretiosum Riley as a potential biological control method against L. luminosa. The AGVM population dynamics showed a similar trend in the three grapevine monitored vineyards. The larvae started occurring at 30 days after pruning (DAP), pre-bloom stage, with a peak population between 54 and 78 DAP, following a decrease until harvest. The AGVM females larva, pupa, and egg-adult period were longer than males. The egg-adult period was 42.1 and 45.2 days for male and females, respectively. Trichogramma pretiosum was able to parasitize L. luminosa eggs. The T. pretiosum egg-adult period was 10.2 days with a 98.5% pupa survivorship at 25 °C. The release of T. pretiosum in the vineyards resulted in 65.5 to 73.2% AGVM egg parasitism. Our findings bring the first biological and population dynamics information for L. luminosa, which can help developing efficient approaches to monitor and control the pest in grapevines. The release of T. pretiosum in the vineyard is a potential biological control option to AGVM.

First report of injuries associated with triclopyr herbicide drift in grapevines / Primeiro relato de danos associados à deriva do herbicida triclopir em videiras

In the southern region of Brazil, close proximity of vineyards to soybean areas is common, and glyphosate is used frequently to allow for the control of weeds. However, the continuous use of this chemical has accelerated the process of selection for resistant species such as horseweed (Conyza spp.), thus leading to the search for alternative herbicides such as triclopyr to control this weed. To the best of our knowledge, this is the first report detailing injuries associated with triclopyr drift in grapevines in Brazil, in the Northern region of Parana state, that can result in crop losses that were previously uncharacterized. In this report, the primary symptoms associated with the drift of triclopyr in grapevines are described. Additionally, the major implications of this process regarding vine development along the next crop seasons are explored, and the primary measures to prevent these injuries are discussed.(AU)

Na região sul do Brasil é comum a proximidade de parreirais às lavouras de soja, sendo que no controle de plantas daninhas é frequentemente utilizado o herbicida glifosato. Porém, o seu uso acelerou o processo de seleção de espécies resistentes, como a buva (Conyza spp.), levando à procura por herbicidas alternativos, como o triclopir para o controle dessa planta daninha. Nesse trabalho é feito o primeiro relato de danos associados à deriva da aplicação de triclopir em áreas de produção de uvas no Brasil na região Noroeste do Estado do Paraná, causando prejuízos à cultura até então desconhecidos. Nessa comunicação, os principais sintomas associados à deriva desse herbicida em videiras são descritos, bem como discutidas as suas principais implicações no desenvolvimento das videiras nos próximos ciclos produtivos, e as medidas para que os danos sejam evitados.(AU)

Control of Gray Mold on Clamshell-Packaged 'Benitaka' Table Grapes Using Sulphur Dioxide Pads and Perforated Liners.

The use of vented clamshells has become popular in the packaging of grapes for local and international markets. The aim of this study is to evaluate the postharvest preservation of 'Benitaka' table grapes individually packaged in vented clamshells using different types of SO2-generating pads and perforated plastic liners during cold storage. A completely randomized design with four replications in a two-factor arrangement with an additional treatment [(4 × 3) + 1] was used. The trials were carried out under two situations: Artificial or natural infections with Botrytis cinerea, which is the causal agent of gray mold on table grapes. The incidence of gray mold, shattered berries, and stem browning were evaluated at 30 and 45 days of cold storage at 1 ± 1 °C and 3 days of shelf-life at 22 ± 1 °C after the period of cold storage. Mass loss and berry firmness were also examined at the end of the cold storage period. The use of dual-release SO2-generating pads containing 5 or 8 g of a.i. and slow-release pads with 7 g of a.i. was effective in controlling the incidence of gray mold in grapes packaged in vented clamshells and kept under cold storage for up to 45 days. Under these storage conditions, perforated plastic liners with 0.3% ventilation area or micro-perforated liners with 1.0% ventilation area reduced the percentage of mass loss and shattered berries.

Cell wall and metabolite composition of berries of Vitis vinifera (L.) cv. Thompson Seedless with different firmness.

Firm berries are highly appreciated by table grape consumers. Cell wall composition is one of the main factors influencing the firmness of table grape berries. Nevertheless, the biological factors driving changes in berry firmness remain unclear. In the present work, we evaluated the firmness of berries of Vitis vinifera cv. Thompson Seedless. We selected two orchards displaying contrasting berry firmness and evaluated polar metabolites and cell wall composition. Our results suggest that berries from the soft orchard exhibited a higher accumulation of sugars at veraison whereas berries from the hard orchard accumulated the same sugars at harvest plus a higher amount of glucose monosaccharide at the cell wall. Thus, this study opens new insights about a connection between metabolic and cell wall changes with fruit firmness in a table grape variety, suggesting that it is possible to use metabolomic tools to identify metabolic biomarkers associated with table grape berry firmness.

Maturação da uva 'Benitaka' cultivada em clima subtropical / Maturation of grape 'Benitaka' cultivated in subtropical climate

Tradicionais produtoras de uvas finas para mesa, as regiões de Pilar do Sul e São Miguel Arcanjo requerem estudos relacionados à evolução da maturação a fim de garantir a colheita de frutos que atendam as exigências de mercado. O objetivo deste trabalho foi avaliar a maturação da uva ‘Benitaka’ cultivada em clima subtropical. O experimento foi realizado em um vinhedo comercial da uva ‘Benitaka’ enxertada no porta-enxerto 420-A, em sistema de condução do tipo pérgola, no sétimo ano de produção, localizado em Pilar do Sul, SP, Brasil (23º 48’ S, 47º 42’ O e altitude de 689m), no ciclo produtivo de 2014/15. A partir do início da maturação, aos 114 dias após a poda (DAP), realizou-se amostragem semanal das bagas para a determinação dos teores de sólidos solúveis (SS), pH, acidez titulável (AT), relação SS/AT e açúcares redutores (AR), se estendendo a amostragem de bagas até a colheita (156 DAP). A uva ‘Benitaka’ cultivada em região subtropical apresentou boas características físico-químicas aos 156 dias após a poda, com valores de SS de 15,99 ºBrix, AT de 0,49 % de ácido tartárico, pH 3,73, relação SS/AT de 32,68 e AR de 14,10%.

Producers traditional of the fines table grapes, the regions of Pilar do Sul and São Miguel Arcanjo require studies related to the evolution of maturation in order to guarantee the harvest of fruits that meet market requirements. The aim of this work was to evaluate the maturation of the grape ‘Benitaka’ grown in subtropical climate. The experiment was conducted in a commercial vineyard of the grape ‘Benitaka’ grafted on the rootstock 420-A, in a pergola-type conduction system, in the seventh year of production, located in Pilar do Sul, SP, Brazil (23º 48 ‘S, 47º 42 ‘W and altitude of 689 m), in the production cycle of 2014/15. From the beginning of maturation, at 114 days after pruning (DAP), weekly sampling of berries was carried out to determine soluble solids (SS), pH, titratable acidity (AT), relationship SS/AT and reducing sugars (RS), extending the sampling of berries until harvest (156 DAP). The grape ‘Benitaka’ cultivated in the subtropical region showed good physicochemical characteristics at 156 days after pruning, with SS values of 15.99 ºBrix, AT of 0.49 % of tartaric acid, pH 3.73, relationship SS/AT of 32.68 and RS of 14.10 %.

Maturação da uva 'Benitaka' cultivada em clima subtropical / Maturation of grape 'Benitaka' cultivated in subtropical climate

Tradicionais produtoras de uvas finas para mesa, as regiões de Pilar do Sul e São Miguel Arcanjo requerem estudos relacionados à evolução da maturação a fim de garantir a colheita de frutos que atendam as exigências de mercado. O objetivo deste trabalho foi avaliar a maturação da uva ‘Benitaka cultivada em clima subtropical. O experimento foi realizado em um vinhedo comercial da uva ‘Benitaka enxertada no porta-enxerto 420-A, em sistema de condução do tipo pérgola, no sétimo ano de produção, localizado em Pilar do Sul, SP, Brasil (23º 48 S, 47º 42 O e altitude de 689m), no ciclo produtivo de 2014/15. A partir do início da maturação, aos 114 dias após a poda (DAP), realizou-se amostragem semanal das bagas para a determinação dos teores de sólidos solúveis (SS), pH, acidez titulável (AT), relação SS/AT e açúcares redutores (AR), se estendendo a amostragem de bagas até a colheita (156 DAP). A uva ‘Benitaka cultivada em região subtropical apresentou boas características físico-químicas aos 156 dias após a poda, com valores de SS de 15,99 ºBrix, AT de 0,49 % de ácido tartárico, pH 3,73, relação SS/AT de 32,68 e AR de 14,10%.(AU)

Producers traditional of the fines table grapes, the regions of Pilar do Sul and São Miguel Arcanjo require studies related to the evolution of maturation in order to guarantee the harvest of fruits that meet market requirements. The aim of this work was to evaluate the maturation of the grape ‘Benitaka grown in subtropical climate. The experiment was conducted in a commercial vineyard of the grape ‘Benitaka grafted on the rootstock 420-A, in a pergola-type conduction system, in the seventh year of production, located in Pilar do Sul, SP, Brazil (23º 48 ‘S, 47º 42 ‘W and altitude of 689 m), in the production cycle of 2014/15. From the beginning of maturation, at 114 days after pruning (DAP), weekly sampling of berries was carried out to determine soluble solids (SS), pH, titratable acidity (AT), relationship SS/AT and reducing sugars (RS), extending the sampling of berries until harvest (156 DAP). The grape ‘Benitaka cultivated in the subtropical region showed good physicochemical characteristics at 156 days after pruning, with SS values of 15.99 ºBrix, AT of 0.49 % of tartaric acid, pH 3.73, relationship SS/AT of 32.68 and RS of 14.10 %.(AU)

Transcriptome profiling of grapevine seedless segregants during berry development reveals candidate genes associated with berry weight.

BACKGROUND: Berry size is considered as one of the main selection criteria in table grape breeding programs. However, this is a quantitative and polygenic trait, and its genetic determination is still poorly understood. Considering its economic importance, it is relevant to determine its genetic architecture and elucidate the mechanisms involved in its expression. To approach this issue, an RNA-Seq experiment based on Illumina platform was performed (14 libraries), including seedless segregants with contrasting phenotypes for berry weight at fruit setting (FST) and 6-8 mm berries (B68) phenological stages. RESULTS: A group of 526 differentially expressed (DE) genes were identified, by comparing seedless segregants with contrasting phenotypes for berry weight: 101 genes from the FST stage and 463 from the B68 stage. Also, we integrated differential expression, principal components analysis (PCA), correlations and network co-expression analyses to characterize the transcriptome profiling observed in segregants with contrasting phenotypes for berry weight. After this, 68 DE genes were selected as candidate genes, and seven candidate genes were validated by real time-PCR, confirming their expression profiles. CONCLUSIONS: We have carried out the first transcriptome analysis focused on table grape seedless segregants with contrasting phenotypes for berry weight. Our findings contributed to the understanding of the mechanisms involved in berry weight determination. Also, this comparative transcriptome profiling revealed candidate genes for berry weight which could be evaluated as selection tools in table grape breeding programs.

Relative humidity during cold storage on Postharvest quality of 'Niagara Rosada' table grapes / Umidade relativa durante o armazenamento refrigerado sobre a qualidade pós-colheita de uvas de mesa 'Niagara Rosada'

This study aimed to evaluate the effect of different levels of relative humidity (RH) on the maintenance of Postharvest quality of 'Niagara Rosada' table grapes after cold storage at 0.5°C for 21 days. A completely randomized design was used, with five replicates of 18 clusters per treatment. The selected levels of relative humidity were 85, 90, 95 and 100%, obtained by means of electronic humidity controllers. The fruits were evaluated in relation to rot incidence, berry cracking, browning rate, respiratory rate, titratable acidity, soluble solids, resistance to abscission, berry drop and weight loss. The evaluations were assessed at 20 days of storage and after two and four days of shelf-life (20°C; 85% RH). The results showed that as higher as relative humidity, higher is rot incidence and that the variables rachis browning and weight loss were inversely related to relative humidity. Resistance to abscission at the end of storage was higher when humidity ranged between 90 and 95%, but it was not affected after transfer to shelf-life from cold storage. Relative humidity ranging between 90 and 95% offer the best conditions to maintain the Postharvest quality of 'Niagara Rosada' table grapes.(AU)

Este trabalho teve como objetivo avaliar o efeito de diferentes níveis de umidade relativa (UR) sobre a manutenção da qualidade pós-colheita de uvas de mesa 'Niagara Rosada', após armazenamento sob refrigeração, a 0,5°C durante 21 dias. Foi utilizado delineamento inteiramente casualizado, com cinco repetições de 18 cachos por tratamento. Os níveis de umidade relativa utilizados foram 85, 90, 95 e 100%, conseguidos com o auxílio de controladores eletrônicos. Os frutos foram avaliados quanto à incidência de podridões e rachaduras, índice de escurecimento, taxa respiratória, acidez titulável, sólidos solúveis, resistência ao degrane, degrane e perda de massa. As avaliações foram realizadas aos 20 dias de armazenamento e após dois e quatro dias de exposição dos frutos à condição ambiente (20°C; 85% UR). Os resultados indicaram que quanto maior o teor de umidade, maior a incidência de podridões, e que as variáveis escurecimento da ráquis e perda de massa possuem relação inversa à umidade relativa. A resistência ao degrane na saída da câmara foi maior com umidade entre 90 e 95%, mas não foi afetada após a transferência dos cachos à condição ambiente. O armazenamento sob refrigeração e umidade relativa na faixa de 90 a 95% proporciona melhor manutenção da qualidade pós-colheita de uvas 'Niagara Rosada'.(AU)

Relative humidity during cold storage on Postharvest quality of 'Niagara Rosada' table grapes / Umidade relativa durante o armazenamento refrigerado sobre a qualidade pós-colheita de uvas de mesa 'Niagara Rosada'

This study aimed to evaluate the effect of different levels of relative humidity (RH) on the maintenance of Postharvest quality of 'Niagara Rosada' table grapes after cold storage at 0.5°C for 21 days. A completely randomized design was used, with five replicates of 18 clusters per treatment. The selected levels of relative humidity were 85, 90, 95 and 100%, obtained by means of electronic humidity controllers. The fruits were evaluated in relation to rot incidence, berry cracking, browning rate, respiratory rate, titratable acidity, soluble solids, resistance to abscission, berry drop and weight loss. The evaluations were assessed at 20 days of storage and after two and four days of shelf-life (20°C; 85% RH). The results showed that as higher as relative humidity, higher is rot incidence and that the variables rachis browning and weight loss were inversely related to relative humidity. Resistance to abscission at the end of storage was higher when humidity ranged between 90 and 95%, but it was not affected after transfer to shelf-life from cold storage. Relative humidity ranging between 90 and 95% offer the best conditions to maintain the Postharvest quality of 'Niagara Rosada' table grapes.

Este trabalho teve como objetivo avaliar o efeito de diferentes níveis de umidade relativa (UR) sobre a manutenção da qualidade pós-colheita de uvas de mesa 'Niagara Rosada', após armazenamento sob refrigeração, a 0,5°C durante 21 dias. Foi utilizado delineamento inteiramente casualizado, com cinco repetições de 18 cachos por tratamento. Os níveis de umidade relativa utilizados foram 85, 90, 95 e 100%, conseguidos com o auxílio de controladores eletrônicos. Os frutos foram avaliados quanto à incidência de podridões e rachaduras, índice de escurecimento, taxa respiratória, acidez titulável, sólidos solúveis, resistência ao degrane, degrane e perda de massa. As avaliações foram realizadas aos 20 dias de armazenamento e após dois e quatro dias de exposição dos frutos à condição ambiente (20°C; 85% UR). Os resultados indicaram que quanto maior o teor de umidade, maior a incidência de podridões, e que as variáveis escurecimento da ráquis e perda de massa possuem relação inversa à umidade relativa. A resistência ao degrane na saída da câmara foi maior com umidade entre 90 e 95%, mas não foi afetada após a transferência dos cachos à condição ambiente. O armazenamento sob refrigeração e umidade relativa na faixa de 90 a 95% proporciona melhor manutenção da qualidade pós-colheita de uvas 'Niagara Rosada'.