@article {4517, title = {Caracteriza{\c c}{\~a}o morfofisiol{\'o}gica e an{\'a}lise de PCR-SSCP de isolados de Phytophthora da ac{\'a}cia-negra na regi{\~a}o Sul do Brasil}, journal = {Summa Phytopathologica}, volume = {37}, year = {2011}, month = {Jan-01-2011}, pages = {92 - 97}, abstract = {

The aim of this study was to characterize Phytophthora isolates from black wattle (Acacia mearnsii) in Southern Brazil, based on phenotypic traits such as morphology, mycelial growth, cultural features, sexual compatibility and pathogenicity, as well as on single strand conformation polymorphism (PCR-SSCP) of\ rDNA ITS-gene 5.8S region. The isolates presented sporangia with prominent papilla, irregularly sympodial sporangia, heterothalic cultures with amphigynous antheridia, presence of chlamydospore and mycelial growth at temperature above 35{\textdegree}C, allowing the classification of all 12 isolates as P. nicotianae. All isolates were pathogenic to black wattle, causing necrosis on stems without gum formation, with significant differences on aggressiveness (P=0.05). Two populations\ of P. nicotianae from black wattle can be distinguished based on PCR-SSCP analysis of rDNA; however, this separation has no apparent correlation with phenotypic traits.

O objetivo do trabalho foi caracterizar isolados de Phytophthora da ac{\'a}cia-negra (Acacia mearnsii) provenientes do Sul do Brasil, com base em caracter{\'\i}sticas fenot{\'\i}picas tais como morfologia, crescimento micelial, caracter{\'\i}sticas das culturas, compatibilidade sexual e patogenicidade, e em perfis de polimorfismo de conforma{\c c}{\~a}o de fita simples (SSCP = Single Strand Conformation Polymorphism) da regi{\~a}o ITS-gene 5.8S do rDNA. Os isolados apresentaram espor{\^a}ngios com papilas proeminentes, arranjo dos espor{\^a}ngios irregularmente simpodial, culturas heterot{\'a}licas com presen{\c c}a de anter{\'\i}dios anf{\'\i}genos, presen{\c c}a de clamid{\'o}sporos e crescimento micelial em temperatura acima de 35{\textdegree}C, permitindo a classifica{\c c}{\~a}o dos 12 isolados como P. nicotianae. Todos os isolados foram patog{\^e}nicos, causando necrose em ramos de ac{\'a}cia-negra, sem forma{\c c}{\~a}o de goma, com diferen{\c c}as significativas de agressividade (p=0,05). Duas popula{\c c}{\~o}es podem ser distinguidas em P. nicotianae da ac{\'a}cia negra pela an{\'a}lise PCR-SSCP do rDNA; no entanto essa separa{\c c}{\~a}o n{\~a}o apresenta aparente correla{\c c}{\~a}o com caracter{\'\i}sticas fenot{\'\i}picas.

}, issn = {0100-5405}, doi = {10.1590/S0100-54052011000300002}, url = {http://www.scielo.br/pdf/sp/v37n3/a02v37n3.pdf}, author = {Alves, TCA and Santos, A. F. dos and Tessmann, DJ and Vida, JB and Harakava, Ricardo} }