Reação de laranjeiras-doces quanto à resistência a Guignardia citricarpa
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Data
2010-09-01
Autores
Sousa, Patrícia Ferreira Cunha [UNESP]
Goes, Antonio de [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira de Fruticultura
Resumo
O objetivo deste trabalho foi determinar o comportamento de variedades de laranjas-doces quanto à resistência a Guignardia citricarpa, agente causal da mancha preta dos citros (MPC). Os ensaios foram conduzidos em dois campos, nos municípios de Rincão e Tambaú, SP. As mudas foram formadas em viveiro localizado na Estação Experimental de Citricultura de Bebedouro-SP. Para tal, foram utilizadas borbulhas de plantas cítricas existentes no Banco Ativo de Germoplasma de Citros da Estação Experimental de Citricultura de Bebedouro (EECB), Bebedouro-SP. Avaliou-se a severidade da doença por meio de escala de notas, de zero (ausência de sintomas) a seis (sintomas severos). A partir de tais dados, foi calculado o valor do índice de doença (ID). em 2007, no experimento de Rincão, dentre as 65 variedades avaliadas, apenas 59 produziram frutos, sendo constatada ausência de sintomas da doença em Castellana, Maçã e Olivelands. Nas demais variedades, os níveis de severidade variaram de 0,35 para Grada a 3,0 para China SRA-547. Para Tambaú, os valores de severidade variaram de 0,40 para a variedade Cadenera a 2,46 para Pera. No ano de 2008, em Rincão, todas as variedades mostraram-se suscetíveis. Os níveis de severidade verificados variaram de 0,18 para a variedade Belladona, e 3,92 para Vera 97. em Tambaú, somente a variedade Navelina não apresentou sintomas da MPC. Foi observado que, dentre as plantas que frutificaram, e com exceção daquelas cujos frutos mostraram-se assintomáticos, os valores de severidade variaram de 0,11 para a variedade Tua Mamede a 3,57 para Amares.
The objective of this research was to determine the variety behavior of sweet oranges as to their resistance to Guignardia citricarpa, a causal agent of citrus black spot (CBS). The tests were conducted in two fields in the cities of Rincão and Tambaú, SP. The seedlings were formed in a nursery located in the Experimental Station of Citriculture (EECB) in Bebedouro, SP. For this, citrus plant buds present in the Active Bank of Citrus Germoplasm (EEBC), were used. The severity of the disease was evaluated by using a grade scale from zero (absence of symptoms) to six (maximum severity). Using this data the disease index (DI) was calculated. In the 2007 harvest, the tests in Rincão showed that only 59 out of the 65 varieties evaluated produced fruit, verifying the absence of the disease symptoms in Castellana, Maçã and Olivelands. In the other varieties, the severity levels vary between 0.35 in Grada, and 3.0 in China SRA-547. In Tambaú, the severity values varied from 0.40 in Cadenera, and 2.46 in Pêra. In 2008, all of the varieties in Rincão showed to be susceptible. The severity levels verified, varied from 0.18 in Belladona and 3.92 in Vera 97. In Tambaú, only the Navelina variety showed no CBS symptoms. Among the plants that flourished, it was observed that the values of severity varied from 0.11 in Tua Mamede and 3.57 in Amares, with the exception of those whose fruits showed to be asymptomatic.
The objective of this research was to determine the variety behavior of sweet oranges as to their resistance to Guignardia citricarpa, a causal agent of citrus black spot (CBS). The tests were conducted in two fields in the cities of Rincão and Tambaú, SP. The seedlings were formed in a nursery located in the Experimental Station of Citriculture (EECB) in Bebedouro, SP. For this, citrus plant buds present in the Active Bank of Citrus Germoplasm (EEBC), were used. The severity of the disease was evaluated by using a grade scale from zero (absence of symptoms) to six (maximum severity). Using this data the disease index (DI) was calculated. In the 2007 harvest, the tests in Rincão showed that only 59 out of the 65 varieties evaluated produced fruit, verifying the absence of the disease symptoms in Castellana, Maçã and Olivelands. In the other varieties, the severity levels vary between 0.35 in Grada, and 3.0 in China SRA-547. In Tambaú, the severity values varied from 0.40 in Cadenera, and 2.46 in Pêra. In 2008, all of the varieties in Rincão showed to be susceptible. The severity levels verified, varied from 0.18 in Belladona and 3.92 in Vera 97. In Tambaú, only the Navelina variety showed no CBS symptoms. Among the plants that flourished, it was observed that the values of severity varied from 0.11 in Tua Mamede and 3.57 in Amares, with the exception of those whose fruits showed to be asymptomatic.
Descrição
Palavras-chave
Citrus sinensis, Phyllosticta citricarpa, Genotypes, Citrus sinensis, Phyllosticta citricarpa, mancha-preta dos citros, Genótipos
Como citar
Revista Brasileira de Fruticultura. Sociedade Brasileira de Fruticultura, v. 32, n. 3, p. 718-725, 2010.