Ester Wickert
Universidade Federal do Rio Grande do Sul
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Featured researches published by Ester Wickert.
Phytopathology | 2007
Ester Wickert; Marcos Antonio Machado; Eliana Gertrudes de Macedo Lemos
ABSTRACT The aim of this study was to obtain information about genetic diversity and make some inferences about the relationship of 27 strains of Xylella fastidiosa from different hosts and distinct geographical areas. Single-nucleotide polymorphism (SNP) molecular markers were identified in DNA sequences from 16 distinct regions of the genome of 24 strains of X. fastidiosa from coffee and citrus plants. Among the Brazilian strains, coffee-dependent strains have a greater number of SNPs (10 to 24 SNPs) than the citrus-based strains (2 to 12 SNPs); all the strains were compared with the sequenced strain 9a5c. The identified SNP markers were able to distinguish, for the first time, strains from citrus plants and coffee and showed that strains from coffee present higher genetic diversity than the others. These markers also have proven to be efficient for discriminating strains from the same host obtained from different geographic regions. X. fastidiosa, the causal agent of citrus variegated chlorosis, possesses genetic diversity, and the SNP markers were highly efficient for discriminating genetically close organisms.
Revista Brasileira De Fruticultura | 2009
Ester Wickert; Antonio de Goes; Eliana Gertrudes de Macedo Lemos; Andressa de Souza; Érico Leandro da Silveira; Fernanda Dias Pereira; Davi Rinaldo
ABSTRACT- Fungi of Guignardia genera are commonly isolated from different plant species and most ofthe time they are characterized as endophytics. However, some species of this genus, as G. citricarpa and G. psidii are known as causal agents of serious diseases that affect cultures, such as the Citrus Black Spotand the guava fruit rot, respectively. They are also responsible for diseases that cause foliar spots indifferent fruit species and also in other cultures. This work has the objective of isolate, identify andcharacterize the genetic diversity present among Guignardia isolates obtained from citrus, mango, guava,eucalyptus, Brazilian grape tree and Surinam cherry by analysis of DNA sequence from cistron ITS1-5,8S-ITS2. It was verified that the obtained isolates belong to G. mangiferae and G. citricarpa species. Twodifferent Guignardia types, that were found in mango, could not be identified in species, and do not belongto none of the species deposited in GenBank. So, this work found that mango, guava, eucalyptus, Braziliangrape tree and Surinam cherry host only
The Scientific World Journal | 2012
Ester Wickert; Eliana Gertrudes de Macedo Lemos; Luciano Takeshi Kishi; Andressa de Souza; Antonio de Goes
Among the citrus plants, “Tahiti” acid lime is known as a host of G. mangiferae fungi. This species is considered endophytic for citrus plants and is easily isolated from asymptomatic fruits and leaves. G. mangiferae is genetically related and sometimes confused with G. citricarpa which causes Citrus Black Spot (CBS). “Tahiti” acid lime is one of the few species that means to be resistant to this disease because it does not present symptoms. Despite the fact that it is commonly found in citric plants, little is known about the populations of G. mangiferae associated with these plants. Hence, the objective of this work was to gain insights about the genetic diversity of the G. mangiferae populations that colonize “Tahiti” acid limes by sequencing cistron ITS1-5.8S-ITS2. It was verified that “Tahiti” acid lime plants are hosts of G. mangiferae and also of G. citricarpa, without presenting symptoms of CBS. Populations of G. mangiferae present low-to-moderate genetic diversity and show little-to-moderate levels of population differentiation. As gene flow was detected among the studied populations and they share haplotypes, it is possible that all populations, from citrus plants and also from the other known hosts of this fungus, belong to one great panmictic population.
The Scientific World Journal | 2012
Ester Wickert; Antonio de Goes; Andressa de Souza; Eliana Gertrudes de Macedo Lemos
One of the most important diseases that affect sweet orange orchards in Brazil is the Citrus Black Spot that is caused by the fungus Guignardia citricarpa. This disease causes irreparable losses due to the premature falling of fruit, as well as its severe effects on the epidermis of ripe fruit that renders them unacceptable at the fresh fruit markets. Despite the fact that the fungus and the disease are well studied, little is known about the genetic diversity and the structure of the fungi populations in Brazilian orchards. The objective of this work was study the genetic diversity and population differentiation of G. citricarpa associated with four sweet orange varieties in two geographic locations using DNA sequence of ITS1-5.8S-ITS2 region from fungi isolates. We observed that different populations are closely related and present little genetic structure according to varieties and geographic places with the highest genetic diversity distributed among isolates of the same populations. The same haplotypes were sampled in different populations from the same and different orange varieties and from similar and different origins. If new and pathogenic fungi would become resistant to fungicides, the observed genetic structure could rapidly spread this new form from one population to others.
Revista Brasileira De Fruticultura | 2012
Renata Aparecida de Andrade; Ester Wickert; Antonio Baldo Geraldo Martins; Eliana Gertrudes de Macedo Lemos
ABSTRACT - The rambutan is an exotic fruit that has a high market potential and the seedlings can be obtained by seed or vegetative. The production of seedlings by seed is routinely done in the state of Sao Paulo, having a high variability in the orchard, and take longer time to go into production. Although morphological characters are widely used in differentiation of the varieties, molecular techniques allow the comparison and identification of genetic material. Thus, the present research was realized, comparing rambutan stock plants and their progenies, by fAFLP. Analyses were realized at the Laboratory of Biochemistry of Microorganisms and Plants, Department of Technology – Faculdade de Ciencias Agrarias e Veterinarias - UNESP - Jaboticabal/SP, using 06 plants of rambutan, denomined: A, B, C, D, E and F. Were collected leaves of 15 seedlings derived from each stock plant and was done the DNA extraction, being the samples quantified according to AFLP Plant Mapping Protocol (Applied Biosystems), using combinations of pairs primers: ACG / CAC, ACT / CAT, ACA / CTT and ACC / CTT. Can be concluded that the use of molecular markers is effective to distinguish the materials and to obtain the genetic distance; is not recommended to obtain seedlings by seed when the purpose is to install a commercial orchard.
The Scientific World Journal | 2012
Ester Wickert; Eliana Gertrudes de Macedo Lemos; Luciano Takeshi Kishi; Andressa de Souza; Antonio de Goes
Ciencia Rural | 2001
Marinês Bastianel; Ana Lúcia Cunha Dornelles; Marcos Machado; Ester Wickert; Simone de Farias Maraschin; Helvécio Della Coletta Filho; Gilmar Schafer
Comunicata Scientiae | 2011
Renata Aparecida de Andrade; Ester Wickert; Antonio Baldo Geraldo Martins; Mariana Macedo Costa de Andrade; Eliana Gertrudes de Macedo Lemos
Ai Magazine | 2014
Ester Wickert; Andressa de Souza; Rodrigo Matheus Pereira; Luciano Takeshi Kishi; Eliana Gertrudes de Macedo Lemos; Antonio de Goes
Comunicata Scientiae | 2011
Renata Aparecida de Andrade; Ester Wickert; Antonio Baldo Geraldo Martins; Mariana Macedo Costa de Andrade; Eliana Gertrudes de Macedo Lemos