Resumo: O oídio em soja, trata-se de uma doença praticamente presente em todos os paises produtores. Os marcadores moleculares microssatélites ou SSR (Simple Sequence Repeat) têm sido amplamente utilizados no processo de seleção assistida de genótipos de soja. Assim, o objetivo deste estudo foi obter marcadores microssatélites próximos ao gene de resistência ao oídio em soja. O estudo foi realizado em duas populações F2, oriundas de cruzamentos entre parentais contrastantes quanto à resistência ao oídio. Para o estudo, foram selecionados marcadores microssatélites a uma distância de até 42 cM ao redor do gene Rmd (resistência ao oídio). Utilizou-se o método de BSA (Bulked Segregant Analysis) na avaliação dos marcadores, para a comparação com a análise fenotípica das populações. Na análise foram utilizados dez iniciadores SSRs para as duas populações, sendo identificados quatro marcadores polimórficos para o cruzamento 1 (MGBR95-20937 x IAC-Foscarin 31) e três para o cruzamento 2 (MGBR 46/Conquista x EMBRAPA 48). Pela análise de Qui-quadrado da avaliação fenotípica, confirmou-se à segregação esperada (3:1) de um gene dominante condicionando a resistência. Os marcadores polimórficos também segregaram conforme o esperado (1:2:1) já que possuem natureza codominante. Para as populações 1 e 2, os melhores resultados foram obtidos com os marcadores Sat_366 e Sat_393, respectivamente, localizando-se a 9,41 e 12,45 cM de distância do gene, sendo considerados promissores na seleção assistida para resistência ao oidio em soja. / Abstract: Powdery mildew in soybeans, it is a disease present in virtually all producing countries. The molecular markers microsatellites or SSR (Simple Sequence Repeat) have been widely used in the assisted selection of soybean genotypes. The objective of this study was to obtain microsatellites markers near the gene for resistance to powdery mildew in soybeans. The study was conducted in two populations F2, from crosses between contrasting parents about the resistance to powdery mildew. For the study, were selected microsatellites markers at a distance of 42 cM around the gene Rmd (resistance to powdery mildew). It was used the method of BSA (Bulked Segregant Analysis) in the evaluation of markers, for comparison with the phenotypic analysis of populations. In the analysis were used in ten initiators SSRs for the two populations, and identified four polymorphic markers for the crossing 1 (MGBR95-20937 x-IAC Foscarin 31) and three for the crossing 2 (EMBRAPA MGBR 46/Conquista x 48). For the analysis of chi-square of the phenotypic evaluation, it is confirmed the segregation expected (3:1) of a dominant gene conditioning the resistance. The polymorphic markers also segregation as expected (1:2:1) that have already codominante nature. For the populations 1 and 2, the best results were obtained with the markers Sat_366 and Sat_393, respectively, finding itself to 9.41 and 12.45 cM distance of the gene and are considered promising in assisted selection for resistance to soybean in powdery mildew. / Orientador: Antonio Orlando Di Mauro / Coorientadora: Sandra Helena Unêda Trevisoli / Banca: Eduardo Antonio Gavioli / Banca: João Carlos de Oliveira / Mestre

Master of Science

No description available.

Bibliography: leaves 148-166. This study identifies genetic variation in Australian Uncinula necator populations. Techniques were developed for molecular and phenotypic markers for U. necator. Mating types of Australian clonal lines were identified and viable cleistothecia and infective ascospores were produced in vitro. The study establishes the foundation for investigating the population biology of U. necator, by identifying two distinct genetic groups, A and B, and micro-geographical variation among 35 clonal lines from various Australian viticultural regions.

Bibliography: leaves 148-166. / vi, 169, [4] leaves, [20] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study identifies genetic variation in Australian Uncinula necator populations. Techniques were developed for molecular and phenotypic markers for U. necator. Mating types of Australian clonal lines were identified and viable cleistothecia and infective ascospores were produced in vitro. The study establishes the foundation for investigating the population biology of U. necator, by identifying two distinct genetic groups, A and B, and micro-geographical variation among 35 clonal lines from various Australian viticultural regions. / Thesis (Ph.D.)--University of Adelaide, Dept. of Crop Protection, 1996

Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.

No description available.

MSCAGR / Department of Plant Production

Podosphaera aphanis which causes powdery mildew of strawberry is of economic importance in strawberry production in United Kingdom as it affects yield and fruit quality. Silicon has been shown to reduce the severity of a number of plant diseases. In strawberry, the mechanism of suppression against powdery mildew remains uncertain. Therefore, it has been suggested that supplying silicon would help strawberry plants to absorb silicon and improve resistance against the pathogen. The silicon based wetter Omex SW7 was used and three different concentrations of silicon wetter were applied on the leaves of the strawberry plants (foliar application). Each treatment was applied at three different timings. Enhanced level of silicon was quantified by the Autoclave Induced Digestion (AID) method. Whilst the main study has used the variety Elsanta, other varieties have also been used. It was observed that the weekly application (total 5 sprays) of 3 different concentrations of Omex SW7 on leaves showed significantly (P<0.05) higher silicon concentrations compared to application 3 times in weeks 1, 3 and 5 or twice in weeks 1 and 5. Microscopic observations showed that weekly application of standard, high and very high concentrations of Omex SW7 significantly (P<0.05) increased the number and length of leaf hairs on both the upper and lower surfaces of strawberry leaves. The different varieties of strawberry used showed morphological changes in the leaves with regard to the density and length of leaf hairs. Untreated leaves from Rhapsody had no hairs on the upper leaf surface, but a low density of hairs was observed after treatment with the high concentration of Omex SW7. In this study, Omex SW7, a silicon based wetter was applied to the roots of strawberry plants (root application) and silicon accumulation and physical changes in leaves were assessed. Strawberry variety Elsanta was used in this experiment. Results revealed that weekly application (total 5 applications) of 2 different concentrations (standard and high) of Omex SW7 to roots showed significantly (P<0.05) higher silicon concentrations compared to application 3 times in weeks 1, 3 and 5 or twice in weeks 1 and 5. It was found that the weekly application of two different concentrations of Omex SW7 showed significantly higher (P<0.05) leaf hair numbers and significantly (P<0.05) longer leaf hair length on both the upper and lower surfaces of leaves compared to application 3 times in weeks 1, 3 and 5 or twice in weeks 1 and 5. The effect of foliar application of silicon and potassium carbonate to limit P. aphanis infection was examined in a field trial under polythene tunnel at Wisbech. Treatments were arranged in a randomised block design of 3 replicates. There were a total of 18 plots. There were six treatments and all treatments were applied to the strawberry variety Sonata. Results revealed that application of silicon based wetter Omex SW7 onto the leaf surface does result in accumulation of silicon in the leaves. The application of Omex SW7 has stimulated an increase in the number and length of leaf hairs in strawberry plants. Results showed that germinating ascospores and colonies were present in all plots before the trial was sprayed. Treatments with standard and high Omex SW7 significantly (P<0.05) reduced the number of germinating ascospores and colonies in this trial. However, Potassium carbonate alone gave some reduction in the number of colonies and germinating ascospores. Moreover, potassium carbonate mixed with silicon based wetter Omex SW7 significantly (P<0.05) reduced the number of germinating ascospores and colonies.

Resumo: A alface é a hortaliça folhosa de maior consumo no Brasil, no entanto a dificuldade em produzi-la vem aumentando, principalmente pela infestação das áreas de produção por Bremia lactucae, sendo necessário o monitoramento anual para utilização ou desenvolvimento de cultivares resistentes. Diante do exposto, os objetivos do presente trabalho foram: identificação de raças de B. lactucae no Estado de São Paulo, durante os anos de 2008, 2009 e 2010 e obtenção de linhagens de alface crespa resistentes às raças SPBl:01, SPBl:02, SPBl:03, SPBl:04, SPBl:05, SPBl:06 e SPBl:07. Na primeira fase do estudo foram coletadas nos meses de agosto, setembro e outubro de 2008; agosto e setembro de 2009; e junho e julho de 2010 folhas de alface com esporângios de B. lactucae nos principais municípios produtores de alface do Estado de São Paulo. Após a multiplicação dos esporângios na cultivar suscetível Solaris, com posterior inoculação nas diferenciadoras, realizaram-se as avaliações, no mesmo dia do aparecimento da primeira esporulação na cultivar suscetível Cobham Green (DM 0). Na segunda fase do estudo realizou-se o cruzamento entre a cultivar Argeles e a linhagem JAB 4-13-7, bem como autofecundações, até a obtenção da geração F3, quando realizou-se o teste de resistência. Os dados permitiram concluir que: três novos códigos "Sextet" para Bremia lactucae ocorreram no Estado de São Paulo: 63/63/33/00, 63/63/02/00 e 63/31/03/00, denominados raças SPBl:05, SPBl:06 e SPBl:07, respectivamente; recomenda-se a utilização dos genes R-17, R-18 e R-38 como fontes de resistência ao míldio para o desenvolvimento de cultivares no Estado de São Paulo; e 19 progênies resistentes à B. lactucae, raças SPBl:01, SPBl:02, SPBl:03, SPBl:04, SPBl:05, SPBl:06 e SPBl:07, apresentaramse homozigotas, e podem ser avançadas e avaliadas no processo de seleção / Abstract: Lettuce is the most consumed leafy vegetable in Brazil. Its production, nonetheless, is meeting with increasing difficulties mainly due to the infestation of producing areas with Bremia lactucae. Thus, the annual monitoring of B. lactucae races becomes of essential importance to use or development of resistant cultivars. The objectives of this work were identification of new races of B. lactucae occurring during the years of 2008, 2009 and 2010 in the state of São Paulo, Brazil, and development of resistant lettuce cultivars to races SPBl:01, SPBl:02, SPBl:03, SPBl:04, SPBl:05, SPBl:06 and SPBl:07. In the first phase of experiment in August, September, and October of 2008; August and September of 2009; and June and July of 2010 lettuce leaf samples containing B. lactucae sporangia were collected in some of the lettuce producing areas of the state of São Paulo. After a multiplication procedure in which the susceptible lettuce cultivar 'Solaris' was used, the B. lactucae sporangia were inoculated in differentiating lettuce cultivars. Evaluations of the plants response were performed on the same day when plants of the susceptible Cobham Green (DM 0) cultivar showed signs of the first sporulation. In the second phase of experiment made the crossing between Argeles cultivar and JAB 4-13-7 line, and self pollination, to obtain the F3 generation, when made the resistant test. The data have identified: three new codes "Sextet" in the state of São Paulo: 63/63/33/00, 63/63/02/00 e 63/31/03/00. SPBl:05, SPBl:06 and SPBl:07 were the denomination proposed to races, respectively. The genes R-17, R-18, and R-38 are suggested to be used as source of resistance in the lettuce cultivars to state of São Paulo; and 19 resistant progenies to B. lactuae, races SPBl:01, SPBl:02, SPBl:03, SPBl:04, SPBl:05, SPBl:06 and SPBl:07, shown homozygous, and they can be advanced and evaluated in the selection process / Orientadora: Leila Trevizan Braz / Coorientador: Tagli Dalpian / Coorientadora: Margarete Camargo / Banca: Pablo Forlan Vargas / Banca: Érika Auxiliadora Giacheto Scalopp / Banca: Rita de Cássia Panizzi / Banca: Joaquim Adelino de Azevedo Filho / Doutor