Diversity of arbuscular mycorrhizal fungi in orchards and seedling growth ofmicropropagated blueberry

O mirtilo ?? uma esp??cie frut??fera de clima temperado de grande import??ncia econ??mica que vem se destacando na regi??o Sul do Brasil. Os objetivos desse trabalho foram avaliar a influ??ncia de fungos micorr??zicos arbusculares (FMA) na produ????o de mudas micropropagadas de mirtilo, assim como isolar e identificar esses fungos oriundos dos pomares da regi??o Sul - RS. Foram coletadas amostras de solo e ra??zes em pomares comerciais e experimentais de mirtilo dos munic??pios de Pelotas, Morro Redondo e Jaguar??o e utilizados ??ndices ecol??gicos como forma de avaliar as popula????es nos pomares em estudo e a an??lise de componentes principais para avaliar os atributos f??sicos e qu??micos do solo em rela????o aos FMAs. Foram identificadas 18 diferentes morfotipos de esporos de FMA. As porcentagens de coloniza????o radicular com FMA foram elevadas, variando de 40 a 80%. Sendo que as variedades localizadas no pomar comercial do munic??pio do Morro Redondo foram as mais colonizadas em rela????o ??s demais. O maior n??mero de esporos foi encontrado na variedade O‟Neal no pomar comercial da Micaela. A abund??ncia relativa e os maiores ??ndices de diversidade Shannon (H‟) e riqueza (R) foram encontrados nas ??reas mais velhas de cultivo, pomar velho experimental da Embrapa (EPV) e do pomar comercial do munic??pio Morro Redondo (MR). A frequ??ncia relativa demonstra a preval??ncia de esp??cies do g??nero Glomus e Acaulospora em todos os pomares. A domin??ncia avaliada pelo ??ndice de Simpsom (Is) apresentou a mesma tend??ncia da diversidade de Shannon e da riqueza. Entre os par??metros qu??micos do solo, houve uma alta correla????o das esp??cies de FMA com as vari??veis pH, V(%), P e areia. Os isolados de FMAs para a produ????o de mudas foram cedidos pelo banco de esp??cies do Departamento de Horticultura e Silvicultura da UFRGS. Testaram-se quatro esp??cies de FMAs (Glomus clarum, Glomus etunicatum e Scutellospora heterogama e Gigaspora margarita) sobre a produ????o de mudas das cultivares Woodard e Bluegem. Os FMAs proporcionaram efeito positivo na produ????o das mudas, em especial Gigaspora margarita que proporcionou melhor nutri????o e maior incremento na biomassa nas plantas da cultivar Woodard e o Glomus etunicatum para a cultivar Bluegem. A efici??ncia da simbiose dos FMAs em cultivares de mirtilo, depende da intera????o especifica FMA X hospedeiro.Blueberries are temperate fruit species of great economic importance that has stood out in Southern Brazil. The objectives of this study were to evaluate the influence of arbuscular mycorrhizal fungi (AMF) on the production of plantlets of blueberry, as well as isolate and identify these fungi from the orchards in the South - RS. Samples were collected from soil and roots in experimental and commercial of blueberry orchards in the municipalities Pelotas, Morro Redondo and Jaguar??o and ecological indexes used as a measure populations in orchards in the study and principal components analysis to assess the physical and chemical soil in relation to the AMF. We identified 18 different morphotypes of spores. The percentages of root colonization with AMF were high, ranging from 40 to 80%. Since the varieties in commercial orchard located in the city of Morro Redondo city were the most colonized in relation to others. The greatest number of spores found in O'Neal in the orchard from Micaela. The relative abundance and the highest Shannon diversity index (H ') and richness (R) were found in the older areas of cultivation, old orchard at Embrapa (EPV) and the commercial orchard in the Morro Redondo city (MR). The relative frequency shows the prevalence of species of the genus Glomus and Acaulospora in all orchards. The dominance evaluated by the Simpson index (Is) showed the same trend as the Shannon diversity and richness. Among the chemical parameters of soil, there was a high correlation of AMF species with varying pH, V (%), P and sand. AMF isolates for the production of seedlings were provided by Bank of species of the Department of Horticulture and Forestry at UFRGS. Were tested four species of AMF (Glomus clarum, Glomus etunicatum, Gigaspora margarita and Scutellospora heterogama) on the production of cultivars Woodard and Bluegem. The AMF would have positive effects in the nursery, particularly Gigaspora margarita which provided better nutrition, and higher biomass of plants growing Woodard and Glomus etunicatum Bluegem for cultivation. The efficiency of the mycorrhizal symbiosis of blueberry cultivars, depends on the interaction specifies AMF X host