DNA similarity studies were used to determine the species of thirty-one strains of bacteria isolated from the hemolymph of infected larvae from Mexico and throughout Central and South America. Twenty-one of the strains were determined to be <I>Paenibacillus popilliae</I> and ten were found to be more closely related to <I>Paenibacillus lentimorbus</I>. Only one of the <I>P. popilliae</I> strains, an isolate from Mexico, was resistant to the antibiotic vancomycin, a trait characteristic of <I>P. popilliae</I> strains from other geographic areas. As expected, all <I>P. lentimorbus</I> strains were sensitive to vancomycin. The polymerase chain reaction (PCR) was used to amplify a portion of a ligase gene necessary for vancomycin resistance in the Mexican strain. Sequencing of the amplicon revealed a sequence identical to that obtained from a North American strain of <I>P. popilliae</I> previously described. The ability of <I>P. popilliae</I> and the inability of <I>P. lentimorbus</I> to grow on medium supplemented with 2% sodium chloride has been used as a phenotypic trait for differentiating between the two species. Approximately 86% of the <I>P. popilliae</I> strains were capable of growth on medium supplemented with 2% sodium chloride and 60% of the <I>P. lentimorbus</I> strains were not capable of growth on this medium. Microscopic examination revealed that all of the Mexican and Central and South American strains of <I>P. popilliae</I> and <I>P. lentimorbus</I> produced a parasporal body. PCR was used to amplify two different regions of the <I>cry18Aa1</I> gene encoding the paraspore in all of the isolates. One primer pair, CryBP2, detected the <I>cry18Aa1</I> gene in 17 of the 21 <I>P. popilliae</I> strains and in all ten of the <I>P. lentimorbus</I> strains. The second primer pair, CryBP4, detected the parasporal gene in 20 of the 21 <I>P. popilliae</I> strains and in all ten of the <I>P. lentimorbus</I> strains. Thirty of the thirty-one <I>P. popilliae</I> and <I>P. lentimorbus</I> strains produced amplicons of approximately 616 bp with the CryBP4 primers. The CryBP4 primers did not detect the paraspore gene in one of the <I>P. popilliae</I> strains. The CryBP2 primer pair produced amplicons of three different sizes, indicating possible variability in the parasporal proteins of <I>P. popilliae</I> and <I>P. lentimorbus</I>. Eleven of the <I>P. popilliae</I> strains produced CryBP2 amplicons approximately 660 bp in size and six of the <I>P. popilliae</I> strains produced CryBP2 amplicons approximately 1100 bp in size. The <I>cry</I> gene was not detected in four of the <I>P. popilliae</I> strains with the CryBP2 primers. The <I>P. lentimorbus</I> strains produced CryBP2 amplicons approximately 750 bp in size. Three PCR products representing the variable CryBP2 amplicon sizes were sequenced and compared to the published <I>cry18Aa1</I> gene sequence. Sequencing data revealed that the Central and South American CryBP2 amplicons are similar to the published <I>cry18Aa1</I> sequence, however, the 1100 bp amplicon has a 453 bp insert that is not found in the published <I>cry18Aa1</I> gene sequence. Paraspores are produced by <I>P. popilliae</I> and <I>P. lentimorbus</I> and is not a reliable phenotypic trait for differentiation between the two species. The ability of Mexican and Central and South American strains of <I>P. lentimorbus</I> to produce paraspores supports the previous findings of a North American group of <I>P. lentimorbus</I> strains that were also capable of producing paraspores. Except for one Mexican strain of <I>P. popilliae</I>, the Central and South American strains of <I>P. popilliae</I> are sensitive to vancomycin. This was unexpected since all North American strains of <I>P. popilliae</I> are vancomycin resistant. Vancomycin resistance could be useful in identifying strains of <I>P. popilliae</I> from North America but not for identifying strains of <I>P. popilliae</I> from Central and South America. So far, no vancomycin resistant strains of <I>P. lentimorbus</I> have been identified. There was variability in the ability of these organisms to grow on medium supplemented with 2% sodium chloride so the usefulness of this trait is debatable. However, the majority of <I>P. popilliae</I> strains from Mexico and Central and South America will grow on medium supplemented with 2% sodium chloride and the majority of the <I>P. lentimorbus</I> strains from these same areas will not grow on this medium. North American strains of <I>P. popilliae</I> and <I>P. lentimorbus</I> also showed variability of growth on medium supplemented with 2% sodium chloride. / Master of Science

Made available in DSpace on 2014-06-11T19:35:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-11-30Bitstream added on 2014-06-13T20:06:05Z : No. of bitstreams: 1 bernardo_era_dr_botfca.pdf: 350867 bytes, checksum: 5ac2bf8356b892e6a8597025678f2c2e (MD5) / O Brasil é o maior produtor de laranja e o maior exportador mundial de suco concentrado. A pinta preta dos citros, causada por Guignardia citricarpa, é uma doença de grande importância econômica, principalmente para o Estado de São Paulo. O interesse no controle biológico de fitopatógenos, como alternativa de controle e como forma de reduzir os problemas ocasionados pelo uso intensivo de fungicidas, tem levado ao desenvolvimento de técnicas alternativas para uma agricultura mais sustentável. O trabalho teve por objetivo avaliar o efeito de agentes de controle biológico (Bacillus subtilis e Trichoderma harzianum) e produtos alternativos (biofertilizantes e leite) no controle da pinta preta dos frutos cítricos em cultivos convencional e orgânico. Além disso, foi avaliado o efeito de Bacillus subtilis, Paenibacillus lentimorbus e Streptomyces sp. no controle de G. citricarpa e Penicillium digitatum em pós-colheita. Os experimentos em campo foram realizados em pomar de laranja`Valência´ e `Pêra´, localizadas nos municípios de Conchal e Santa Eudóxia, SP, respectivamente. Em cultivo convencional de `Valência´ foram avaliados dois biofertilizantes (Microgeo® e Bio2), nas safras 2003/2004 e 2004/2005, com 15 repetições por tratamento, sendo uma planta por repetição. As árvores foram pulverizadas em intervalos de 28 dias, sendo o início em 08/12/03, para a safra 2003/2004 e 08/11/2004, para a safra 2004/2005. Na safra 2003/2004 as concentrações utilizadas do biofertilizante Microgeo® foram 0; 10; 20; 30 e 40%. Na safra 2004/2005 foram repetidos os mesmos tratamentos dasafra anterior e incluído tratamento com o biofertilizante Bio2 nas concentrações de 0; 2,5; 5,0; 7,5 e 10%. Para as avaliações foram utilizadas uma escala de notas de 1=0,5% a 6=49% da área do fruto atacada. Os biofertilizantes apresentaram comportamento... / Brazil is the worldwide biggest producer and exporter of orange and orange juice. The citrus black spot (CBS), caused by Guignardia citricarpa, is a disease of great economic importance, mainly for the São Paulo State. The interest in biological control of plant pathogens, as mitigation of the problems caused by intensive use of fungicides, has led to development of alternative techniques for a more sustainable agriculture. The objective of this work was to evaluate the effects of biocontrol agents (Bacillus subtilis and Trichoderma sp.) and other biocompatible products (cow milk and biofertilizers) for managing CBS in organic and conventional systems. Besides, the effect of B. subtilis, Paenibacillus lentimorbus and Streptomyces sp. for control of G. citricarpa and Penicillium digitatum, in post-harvest was also evaluated. The filed experiments were carried through in trees of `Valencia' and `Pera´, located in Conchal and Santa Eudóxia, SP, respectively. In `Valencia´ conventional system were evaluated two biofertilizers (Microgeo® and Bio2). The experiments were conducted at harvests 2003/2004 and 2004/2005. The trees were sprayed in 28 days intervals, and the first was in 08 December 2003 in 2003/2004 harvest, and 08 November 2004 in 2004/2005 harvest.

Orientador: Wagner Bettiol / Banca: Antonio Carlos Maringoni / Banca: Edson Luiz Furtado / Banca: Antonio de Goes / Banca: Katia Cristina Kupper Moretto / Resumo: O Brasil é o maior produtor de laranja e o maior exportador mundial de suco concentrado. A pinta preta dos citros, causada por Guignardia citricarpa, é uma doença de grande importância econômica, principalmente para o Estado de São Paulo. O interesse no controle biológico de fitopatógenos, como alternativa de controle e como forma de reduzir os problemas ocasionados pelo uso intensivo de fungicidas, tem levado ao desenvolvimento de técnicas alternativas para uma agricultura mais sustentável. O trabalho teve por objetivo avaliar o efeito de agentes de controle biológico (Bacillus subtilis e Trichoderma harzianum) e produtos alternativos (biofertilizantes e leite) no controle da pinta preta dos frutos cítricos em cultivos convencional e orgânico. Além disso, foi avaliado o efeito de Bacillus subtilis, Paenibacillus lentimorbus e Streptomyces sp. no controle de G. citricarpa e Penicillium digitatum em pós-colheita. Os experimentos em campo foram realizados em pomar de laranja'Valência' e 'Pêra', localizadas nos municípios de Conchal e Santa Eudóxia, SP, respectivamente. Em cultivo convencional de 'Valência' foram avaliados dois biofertilizantes (Microgeo® e Bio2), nas safras 2003/2004 e 2004/2005, com 15 repetições por tratamento, sendo uma planta por repetição. As árvores foram pulverizadas em intervalos de 28 dias, sendo o início em 08/12/03, para a safra 2003/2004 e 08/11/2004, para a safra 2004/2005. Na safra 2003/2004 as concentrações utilizadas do biofertilizante Microgeo® foram 0; 10; 20; 30 e 40%. Na safra 2004/2005 foram repetidos os mesmos tratamentos dasafra anterior e incluído tratamento com o biofertilizante Bio2 nas concentrações de 0; 2,5; 5,0; 7,5 e 10%. Para as avaliações foram utilizadas uma escala de notas de 1=0,5% a 6=49% da área do fruto atacada. Os biofertilizantes apresentaram comportamento ...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Brazil is the worldwide biggest producer and exporter of orange and orange juice. The citrus black spot (CBS), caused by Guignardia citricarpa, is a disease of great economic importance, mainly for the São Paulo State. The interest in biological control of plant pathogens, as mitigation of the problems caused by intensive use of fungicides, has led to development of alternative techniques for a more sustainable agriculture. The objective of this work was to evaluate the effects of biocontrol agents (Bacillus subtilis and Trichoderma sp.) and other biocompatible products (cow milk and biofertilizers) for managing CBS in organic and conventional systems. Besides, the effect of B. subtilis, Paenibacillus lentimorbus and Streptomyces sp. for control of G. citricarpa and Penicillium digitatum, in post-harvest was also evaluated. The filed experiments were carried through in trees of 'Valencia' and 'Pera', located in Conchal and Santa Eudóxia, SP, respectively. In 'Valencia' conventional system were evaluated two biofertilizers (Microgeo® and Bio2). The experiments were conducted at harvests 2003/2004 and 2004/2005. The trees were sprayed in 28 days intervals, and the first was in 08 December 2003 in 2003/2004 harvest, and 08 November 2004 in 2004/2005 harvest. / Doutor