Técnicas sorológicas e moleculares na avaliação genética e fitossanitária de mudas e matrizes de videira

• Ano de defesa: 2010
• Autor(a) principal: Sant'ana, Gustavo César
• Orientador(a): Oliveira, Aluízio Borém de
• Banca de defesa: Ferreira, Juliano Lino , Tavares, Mara Garcia
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Marcadores moleculares; Diversidade genética; Genotipagem; Vitis spp.; Vírus; Indexação sorológica
• Palavras-chave em Inglês: Molecular markers; Genetic diversity; Genotyping; Vitis spp., Virus; Serological indexing
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/4733

The grapevine is a perennial fruit of greater economic importance worldwide. Although not among the world's largest producer, Brazil has been showing a growing development in the industry, and production area has increased markedly with the renovation of the vineyards and new plantings. For the deployment and renewal of vineyards wine growers in Brazil have faced serious problems related to lack of plantlets with the genetic and phytossanitari quality tested by national especialisaded companies. Thus, the lack of a private or official certification program of plants, in order to prevent the spread of propagation material of dubious genetic and sanitary quality, has hindered the development of the national viticulture. The aim of this work was (I) the genetic caracterization (DNA fingerprinting) and the analysis of the genetic diversity of 27 grape varieties cultivated in Minas Gerais, Brazil, using SSR molecular markers; and (II) to identify and map the occurrence of viruses in the grapevine Core collection of EPAMIG Grape and Wine, which are used for production of grafted plants, and analyzing the evolution of viral titer of infected plants along the grape phenological cycle by means of DASELISA serological method. Among the 27 cultivars analyzed, 26 different SSR profiles were detected. In this work were identified 101 alleles in 7 loci analyzed with average of 14.43 alleles per locus, confirming the high power of these markers for genetic polymorphism detection. The expected heterozigosity ranged from 0.832 to 0.9205 with average 0.8873 while the observed heterozigosity ranged from 0.7692 to 1.000 with average of 0.8943. The high number of heterozygous individuals might be due the breeding selection followed by genotype maintenance through vegetative propagation. Grapes are known to be very sensitive to inbreeding depression and the higher performance is mainly observed in heterozygous individuals. The loci with highest polymorphisms content (PIC) were VVS2 (0.92), VVMD27 (0.918) and VrZAG62 (0.918) while the loci with lowest values of PIC were VVMD25 (0.832) and VrZAG79 (0.845). Considering the 7 loci analyzed the PI accumulation was very low (1.27 x 10-12) indicating the high efficiency of these loci for grapevine genotypes differentiation. The dendrogram showed four main groups and they were in agreement with the genetic similarity (pedigree) of these varieties. In the principal coordinate analysis, the group formed for 4 Americans varieties showed the highest level of genetic structuration. Despite no clear division was observed between vinifers and rootstocks groups during the structuration, the results indicates a tendency of clustering among the varieties belonging to the same group. Regarding the study of viruses plants of six canopy varieties ('Syrah', 'Chardonnay', 'Cabernet Sauvignon', 'Merlot', 'Bordo' and 'Niagara Rosada'), four rootstock varieties ('Traviú', '1103 Paulsen, 'I'AC 572' and 'IAC 766') and nine combinations of seedlings produced from grafted plants. Twelve 'Bordo' clones belonging to a clonal selection breeding program based of EPAMIG were also analyzed. The plants were tested for the following viruses: GLRaV-1, GLRaV-2, GLRaV-3, GLRaV-6, GVA, GFkV and GFLV. Bordo clones had a high rate of infection with GLRaV-2, which was detected in 91.66% of samples. The GLRaV-1 were detected in two clones (3 and 17), whereas the GLRaV-3 were also detected in two clones (3 and 07). Analyzing mother plants and seedlings produced from them, from a set of 7 seven virus studied, only GLRaV-3 was detected, being present in Niagara Rosada mother plants and in two rootstocks ( IAC 572 and IAC 766 ). The variation in viral titer along the phenological cycle showed an increase in the concentration of viral particles of the three viruses analyzed (GLRaV-1, GLRaV-2, and GLRaV-3).