Jean Carlos Bettoni

CRYOTHERAPY: A NEW TECHNIQUE TO OBTAIN GRAPEVINE PLANTS FREE OF VIRUSES

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.

PRODUTIVIDADE E QUALIDADE DE UVAS DA CV. ISABEL (Vitis labrusca L.) SUBMETIDAS À ADUBAÇÃO POTÁSSICA

^a Videiras ‘Isabel’ enxertadas em porta-enxerto ‘SO4’ e ‘IAC 766’, e em pe-franco plantadas sobre Nitossolo foram tratadas anualmente com doses crescentes de K2O, a 0; 60; 120 e 180 kg ha-1, durante 5 safras viticolas (2007/2008; 2008/2009; 2009/2010; 2010/2011; 2011/2012). O delineamento experimental foi em faixas, com cinco repeticoes, sendo seis plantas por repeticao, e os tratamentos, dispostos em esquema fatorial 4x3, com 12 tratamentos, correspondentes as quatro doses de adubacao potassica e aos tres portaenxertos. No estadio de mudanca de cor da casca das bagas, coletaram-se peciolos para determinar o teor de nutrientes no tecido foliar das uvas. Na ocasiao da colheita, foram avaliados comportamentos vegetativos e produtivos, como produtividade, peso de poda, indice de Ravaz e caracteristicas quimicas da polpa das bagas, como solidos soluveis totais, acidez total titulavel e pH. O aumento da adubacao potassica nao representa ganho na produtividade na cv. Isabel nem no acumulo de solidos soluveis totais nas uvas. K e Mg nos peciolos de uvas sao influenciados pela forma de cultivo (enxertada ou pe-franco). Videiras ‘Isabel’ cultivadas em pe-franco tem menor capacidade de acumulo de K e maior acumulo de Mg nos peciolos. Nas condicoes do solo em que foi desenvolvido o trabalho, nao se justifica a adubacao potassica do vinhedo.^lpt^a^len

ESTAQUIA LENHOSA DE PORTA-ENXERTOS DE VIDEIRA PROMISSORES PARA REGIÕES COM HISTÓRICO DE MORTE DE PLANTAS

The aim of this study was to evaluate the concentrations of indole-3-butyric acid (IBA) in hardwood cuttings of promising grapevine rootstocks for southern Brazil. Plant material was collected from selected plants from the grapevine rootstock collection of EPAGRI Experimental Station, in the city of Videira - SC . The experiment was conducted in a greenhouse during the period from July to October 2013. The experimental design was completely randomized with 20 treatments arranged in a 4x5 factorial scheme, consisting of four rootstocks ( VR043-43, Dogridge, Richter 99 and EEV793-5 ) and five IBA concentrations ( 0 , 1.000 , 2.000, 3.000 and 4.000 mg L- 1). After 60 days, it was evaluated the rooting percentage, the number, length and the fresh weight of the roots. The use of IBA increased rooting percentage, number, length and fresh weight of roots for all rootstocks. The rootstock VR043-43 showed better root development than the other rootstocks studied. To propagate the four cultivars of grapevine rootstocks evaluated via hardwood cuttings it is recommended the use of IBA at 1000 mg L- 1.