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-Through in vitro tissue culture techniques it is possible to propagate high quality nursery plants faster. Cryotherapy is a promising tool, based on in vitro culture techniques, for achieving in a short time, high frequency of regenerating plants free of viruses. The objective of this review is to present and analyze the results of research conducted in cryotherapy methods based on cryopreservation protocols for recovery of cultivars free of micro-organisms with potential agronomic interest. The main methods employed in cryotherapy are encapsulation-dehydration, vitrification, encapsulation-vitrification and droplet vitrification, which are based on the immersion of preconditioned shoot tips in liquid nitrogen, followed by their recovery in vitro on to culture media for regeneration of healthy plantlets. Improvements to cryotherapy protocols used for grapevine are still needed, since there are variations in response according to the genotype. The published research mostly relates to Vitis vinifera and the few studies applied to other species show that the protocols need to be improved. This specificity goes beyond species, with different responses among cultivars, limiting the broader application of the technology. On the other hand, traditional methods used for virus removal from infected plant materials also have limitations and therefore investment in research for the development and application of cryopreservation techniques is highly justified, considering its efficiency and low-cost, once the protocols are developed. High frequency of virus-free plants among regenerants within a short time frame is the most desirable aspect of cryotherapy. Therefore, these advantages make the technique a promising tool for institutions mandated to the development of high-health planting materials with high genetic and agronomic potential for viticulture. Index Terms: Vitis, encapsulation-dehydration, encapsulation-vitrification, vitrification, droplet-vitrification, plant disease. CRIOTERAPIA: UMA NOVA TÉCNICA PARA OBTENÇÃO DE PLANTAS DE VIDEIRA LIVRES DE VIROSESRESUMO -Por meio de técnicas de cultura de tecidos in vitro é possível propagar plantas matrizes de alta qualidade, mais rápido. A crioterapia é uma ferramenta promissora, baseada em técnicas de cultura in vitro para obtenção em curto espaço de tempo de alta frequência de plantas regenerantes livres de viroses. O objetivo desta revisão é apresentar e analisar os resultados de pesquisas realizadas em métodos de crioterapia, baseados em protocolos de criopreservação, para recuperação de cultivares de videiras livres de microorganismos e com potencial de interesse agronômico. Os principais métodos utilizados para crioterapia são encapsulamento-desidratação, encapsulamento-vitrificação, vitrificação e vitrificação de gota, os quais se fundamentam na imersão de ápices meristemáticos pré-condicionados em nitrogênio líquido, seguido por sua recuperação in vitro em meios de cultura para regeneração de plântulas saudáveis. Melhorias para protocolos de crioterapia ...

The availability of and easy access to diverse Vitis species are prerequisites for advances in breeding programs. Plant genebanks usually maintain collections of Vitis taxa as field collections that are vulnerable to biotic and abiotic stresses. Cryopreservation has been considered an ideal method of preserving these collections as safety back-ups in a cost-effective manner. We report a droplet vitrification method used to cryopreserve 12 Vitis species (Vitis vinifera cvs. Chardonnay and ‘Riesling, V. actinifolia, V. aestivalis, V. jacquemontii, V. flexuosa, V. palmata, V. riparia, V. rupestris, V. sylvestris, V. ficifolia, V. treleasi, and V. ×novae angeliae) using shoot tips excised from plants grown in vitro. Our results demonstrated wide applicability of this technique, with regrowth levels at least 43% for 13 genotypes representing 12 Vitis species. We demonstrated that the droplet vitrification procedure can be successfully replicated by technical staff, thus suggesting that this method is ready for implementation.

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Apple stem pitting virus (ASPV), Apple chlorotic leaf spot virus (ACLSV) and Apple stem grooving virus (ASGV) are several major viral pathogens of apple trees, responsible for substantial damage to the world's apple industry. This study aimed to evaluate the effectiveness of the encapsulation-dehydration cryopreservation technique to eradicate these viral pathogens from in vitro shoot tips excised from 'Marubakaido' apple rootstock cultures. Axillary shoot tips were excised from in vitro cultures, encapsulated in alginate beads, precultured in MS salts, dehydrated in a laminar flow hood, immersed in liquid nitrogen, then warmed and recovered on medium. After LN exposure, in vitro rooting and acclimatization, recovered 'Marubakaido' plants exhibited 52% survival and 35% regrowth without callus formation. After 8 months of regrowth, PCR analyses revealed that all the plants were free of ACLSV and ASPV, but 2 out of 20 recovered plants were still infected with ASGV. This is the first report in Brazil of the application of cryotherapy to eradicate viral complexes in Malus. Cryotherapy can facilitate the production of virus-free plants by producing high quality plant material.

Certain viruses dramatically affect yield and quality of potatoes and have proved difficult to eradicate with current approaches. Here, we describe a reliable and efficient virus eradication method that is high throughput and more efficacious at producing virus-free potato plants than current reported methods. Thermotherapy, chemotherapy, and cryotherapy treatments were tested alone and in combination for ability to eradicate single and mixed Potato virus S (PVS), Potato virus A (PVA), and Potato virus M (PVM) infections from three potato cultivars. Chemotherapy treatments were undertaken on in vitro shoot segments for four weeks in culture medium supplemented with 100 mg L−1 ribavirin. Thermotherapy on in vitro shoot segments was applied for two weeks at 40°C (day) and 28°C (night) with a 16 h photoperiod. Plant vitrification solution 2 (PVS2) and cryotherapy treatments included a shoot tip preculture followed by exposure to PVS2 either without or with liquid nitrogen (LN, cryotherapy) treatment. The virus status of control and recovered plants following therapies was assessed in post-regeneration culture after 3 months and then retested in plants after they had been growing in a greenhouse for a further 3 months. Microtuber production was investigated using in vitro virus-free and virus-infected segments. We found that thermotherapy and cryotherapy (60 min PVS2 + LN) used alone were not effective in virus eradication, while chemotherapy was better but with variable efficacy (20–100%). The most effective result (70–100% virus eradication) was obtained by combining chemotherapy with cryotherapy, or by consecutive chemotherapy, combined chemotherapy and thermotherapy, then cryotherapy treatments irrespective of cultivar. Regrowth following the two best virus eradication treatments was similar ranging from 8.6 to 29% across the three cultivars. The importance of virus removal on yield was reflected in “Dunluce” free of PVS having higher numbers of microtubers and in “V500’ free of PVS and PVA having a greater proportion of microtubers > 5 mm. Our improved procedure has potential for producing virus-free planting material for the potato industry. It could also underpin the global exchange of virus-free germplasm for conservation and breeding programs.

RESUMO -Neste estudo, objetivou-se determinar os efeitos da aplicação exógena de ABA e ETEFOM sobre a maturação e a qualidade de uvas Cabernet Sauvignon. O presente trabalho foi realizado em um vinhedo, localizado na Estação Experimental da Epagri de Videira -SC, durante a safra de 2009/2010. Foram utilizadas as doses de 0; 20 e 40g i.a. 100L -1 de ácido abscísico (ABA) e 0; 136,8 e 273,6g i.a. 100L -1 de ETEFOM, configurando um experimento fatorial 3x3. Os tratamentos foram aplicados no início da mudança de cor das bagas "veraison". As variáveis analisadas nas uvas foram teor de antocianinas, polifenóis totais, índice CIRG (índice de cor para uvas tintas), atividade antioxidante, sólidos solúveis totais (ºBrix) e acidez total titulável. Os resultados indicam melhoria na qualidade das uvas com o uso das combinações de ABA e ETEFOM, aumento do índice CIRG, polifenóis totais, antocianinas e açúcares. Termos para indexação: Vitis vinifera L., reguladores de crescimento, coloração das bagas, antocianinas, polifenóis totais. ABSCISIC ACID AND ETEFOM: INFLUENCE ON THE MATURITY AND QUALITY OF CABERNET SAUVIGNON GRAPESABSTRACT -This study aimed to determine the effects of exogenous application of ABA and ETEFOM on the maturation and quality of Cabernet Sauvignon. This study was performed in a vineyard, located at INTRODUÇÃOA vitivinicultura brasileira vem evoluindo nos últimos anos em busca de novas tecnologias que introduzam melhorias na qualidade do vinho, tornando-o competitivo no cenário internacional. Inúmeras são as dificuldades brasileiras na produção de vinhos de qualidade, principalmente as relacionadas com fatores ambientais, tais como solo e clima. Na maioria dos anos, a alta incidência de chuvas e a baixa amplitude térmica durante a maturação das uvas fazem com que elas não alcancem índices ótimos de maturação.A Epagri de Videira difundiu aos agricultores da região um sistema que usa cobertura plástica para a proteção da parreira contra a umidade excessiva na folha, proporcionada pela alta precipitação. A diminuição da umidade nas folhas promove a diminuição do aparecimento de doenças fúngicas; no entanto, os agricultores têm percebido a diminuição na coloração de uvas tintas com o uso de cobertura plástica.O uso de reguladores de crescimento na maturação das uvas vem sendo empregado em vários países. Alguns estudos demonstram que aplicações externas de ABA (ácido abscísico) e ETEFOM (áci-

The micropropation is an important biotechnological tool for obtaining and maintaining mother vine plants with high quality plant health. The objective was to evaluate the establishment and multiplication in vitro and ex vitro acclimatization of grape genotypes with potential for Southern Brazil. Vine nodal segments were cultured in five culture medium formulations without adding growth regulators. It was evaluated the number of leaves and roots, length of roots and shoots, replication rate, relative chlorophyll index, percentage of regenerated and rooted plants, dry biomass of shoot, root and total plants grown in vitro and after acclimatization. In vitro propagation of IAC 571-6 rootstock and cv. Poloskei Muskotaly through nodal segments provided high rates of regeneration and rooting. High survival rates were obtained in the acclimatization of IAC 571-6 and Pölöskei Muskotaly. Considering all the variables, the culture medium Roubelakis showed the best growth rates and development for shoots and roots, and in vitro multiplication rate for IAC 571-6 and Poloskei Muskotaly grape varieties.