Soybean (Glycine max L. Merr.) is one of the most important crops of the world. Among the various viruses infecting soybean, peanut mottle virus is most commonly found on soybeans in areas where they are grown in close proximity to peanuts. This research was conducted with the primary objective of identifying new genes for resistance to peanut mottle virus. To assign a gene symbol to the resistance gene in cultivar CNS, it was crossed with 'Peking'. Both the F2 and F2:3 lines segregated in a ratio which is expected when one dominant and one recessive gene at two different loci are segregating. Previous studies indicate the presence of one dominant gene in CNS and one recessive gene in Peking for resistance against PMV. This clearly suggests that Peking and CNS possess different resistance genes, which are non-allelic to each other. Now that, all the allelism tests are complete, the resistance gene in CNS can be assigned a gene symbol of Rpv3. PI 486355, a resistant line, was crossed with susceptible cultivars Lee 68 and Essex to study the mode of inheritance of resistance. This PI was found to possess two independent dominant genes for resistance to peanut mottle virus. It was also crossed with 'York' and CNS which are known to have resistance genes at the Rpv1 and Rpv3 loci, respectively. Data from inoculations of F2 and F2:3 progenies indicated that one gene was allelic to Rpv1 and the other is at a locus different from both Rpv1 and Rpv3. PI 398593 was crossed with Lee 68, York, Peking and CNS for studying the nature of resistance genes present in it. No certain conclusions can be drawn regarding the nature of the resistance gene(s) at this stage because of inconsistent behavior of the PI itself. The F2 data of the crosses of PI 398593 with Lee 68, York and CNS supported a recessive nature of the resistance gene present in the PI. F2 plants of the cross PI 398593 x Peking segregated but, not in the expected ratio. F2:3 data of only one cross (PI 398593 x York) supported the recessive nature of the PI resistance gene whereas the other two crosses (PI 398593 x CNS and PI 398593 x Peking) did not support these findings. From the data available it appears that the resistance is at least partially influenced by the environment. The mode of inheritance of resistance in PI 96983, 'Kwanggyo', 'Toano', 'Jizuka', 'Raiden' and 'Suweon 97' was studied by crossing these cultivars with PMV susceptible cultivars and inoculating the F2 populations of these crosses. In all these cultivars resistance is governed by a single dominant gene. PI 96983, Toano, Jizuka and Suweon 97 were also crossed with York to determine the allelic relationships. Resistance genes in all these cultivars were found to be allelic to Rpv1. Since each of the cultivars also has a single dominant gene at the same locus for resistance to soybean mosaic virus, it is possible that resistance to both viruses is controlled by the same gene. / Master of Science

A Thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg for the Degree of Doctor of Philosophy / Greening is a severe disease of citrus and is a major cause of crop loss in many parts of Africa and Asia.Numerous attempts have been made by various workers to isolate the aetiological agent of the disease and although reports claiming the successful culture of the organism have appeared, the isolations were never fully confirmed. ( Abbreviation abstract ) / AC2017

This project was performed at Rochester Institute of Technology to get more understanding and knowledge about AM and FM screenings similarities and differences with considerations of the mottle. By designing a test form conformed to the specific measurements and printing it on Heidelberg's Sunday 2000 press, the project group has evaluated the questions that already existed and the ones that occurred during the project. Hence the first press run left some unexpected phenomenon therefore another press run was performed. Measurements were performed and graphs produced in Excel. The project group evaluated the results and from that able to establish facts and draw conclusions. It has been a great experience for the project group and they have learnt a lot.

Submitted by Marco Antônio de Ramos Chagas (mchagas@ufv.br) on 2018-09-19T11:12:48Z No. of bitstreams: 1 texto completo.pdf: 1966574 bytes, checksum: 9a74f6b3cb6b04d280008a26f090b161 (MD5) / Made available in DSpace on 2018-09-19T11:12:48Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1966574 bytes, checksum: 9a74f6b3cb6b04d280008a26f090b161 (MD5) Previous issue date: 2017-02-23 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / A cultura do feijoeiro comum no Brasil, além do imenso valor que representa na cadeia econômica e para milhares de agricultores no país, é fundamental devido à contribuição que possui na segurança alimentar da população. Cultivares com evento de resistência ao Bean golden mosaic virus (begomovirus), vírus responsável por causar uma das doenças que mais afeta a produtividade da cultura no país, foram desenvolvidas após vários anos de pesquisas. Infecções durante testes em campo desses materiais por outro vírus, o Cowpea mild mottle virus (carlavirus), gerou novas preocupações tanto aos pesquisadores envolvidos no projeto do feijoeiro resistente ao mosaico dourado quanto aos produtores que aguardavam a liberação comercial dessas cultivares. Apesar de alguns trabalhos já terem sido desenvolvidos a fim de se avaliar os prejuízos produtivos que o CPMMV causa sobre as isolinhas transgênicas de feijoeiro, assim como sua distribuição, nenhum conhecimento se tem sobre a diversidade desse vírus em feijão comum ou transgênico no Brasil, e poucos trabalhos dessa natureza são encontrados na literatura até hoje. Nesse trabalho, buscou-se avaliar a variabilidade de populações do CPMMV para cada uma de quinze cultivares de feijoeiro comum, sendo dez transgênicas (resistentes ao BGMV) e cinco convencionais, em um campo experimental com ocorrência e transmissão natural do CPMMV. Também foram quantificados os níveis virais em cada cultivar a partir de três repetições. Para cada uma das quinze plantas representando 15 diferentes genótipos de feijoeiro comum, o genoma completo de cinco isolados de CPMMV foi sequenciado pela montagem de sequenciamentos de blocos de PCR. Diferenças foram encontradas na variabilidade dos cinco isolados de CPMMV em plantas transgênicas e em plantas convencionais. Os valores dos descritores de variabilidade π, S, K e Θ foram geralmente maiores nos grupos de isolados de plantas transgênicas. Isso se repetiu para todas as ORF’s virais analisadas. As ORF’s 2, 3 e 4 foram as que tiveram a maior diversidade registrada, enquanto que a diferenças entre os grupos já citados foi mais perceptível nas regiões das ORF’s 2, 5 e 6. Eventos de recombinação foram encontrados na ORF 1 viral, quase sempre ocorrendo em isolados de plantas transgênicas, assim como alguns na ORF 2 e 6. Analisando as sequencias da ORF 1, nota-se que os cinco isolados de cada planta se agrupam e tendem a formar clados próximos a grupos de isolados de genótipos hospedeiros similares, o que pode decorrer da interação entre a replicase viral e a planta. Para a região 3’ do genoma, houve a separação do conjunto de 75 isolados em dois grupos de variantes. A identidade nucleotídica par a par entre isolados de grupos distintos variou entre 75 e 85%. Pelos testes de seleção, existe evidência significativa de que vária populações virais estão sobre processo de seleção não neutra. O acúmulo viral não teve diferença significativa entre plantas transgênicas e convencionais. A quantificação também não revelou diferenças em níveis virais em plantas transgênicas originadas de retrocruzamentos com a cultivar Pérola em comparação aos níveis naquelas retrocruzadas com a cultivar BRS Pontal. Os resultados desse trabalho reforçam resultados anteriores de que dois grupos de estirpes de CPMMV estão distribuídos pelas regiões produtoras brasileiras, provavelmente pela presença em plantas daninhas (onde a variabilidade desse vírus nunca foi analisada) e em hospedeiros cultivados como o próprio feijoeiro. Também comprova a alta variabilidade desse vírus de RNA, principalmente nas novas cultivares de feijoeiro resistente ao mosaico dourado por transgenia. É provável que a presença de BGMV nas cultivares convencionais e consequentemente a infecção mista dos dois vírus tenha algum efeito sobre os valores de variabilidade apresentados nesse estudo. Os mecanismos moleculares dessa interação, porém, não são conhecidos. Os resultados apresentados e o fato de que hospedeiros não cultivados estão distribuídos por grandes áreas de produção e que estes podem atuar como reservatório viral, além da grande distribuição da mosca branca pelo Brasil, fazem com que novos trabalhos com esse patógeno sejam de extrema importância. / The common bean crop in Brazil, besides its economic importance, represents a major source of what is daily consumed by Brazilian population in terms of proteins and carbohydrates, contributing to food security. Cultivars with a transgenic resistance event to Bean golden mosaic virus (begomovirus), a virus that causes one of the most important diseases of common bean, were developed after many years of research. The release of these cultivars immune to BGMV is undergoing difficulties because of the re-emergence of Cowpea mild mottle virus (carlavirus) in common bean, which has raised some concerns for the researchers and the growers. Although works to access the damage potential into different genotypes of these resistant isolines and to investigate the virus distribution are being reported, no study is found evaluating CPMMV molecular characteristics and diversity in transgenic as well as conventional common bean cultivars in Brazil. In fact, there are very few studies of this kind globally. The objective of this work was to evaluate the variability on CPMMV populations from each of the fifteen common bean cultivars, ten transgenic and resistant to BGMV, and five conventional cultivars, from a field experiment with natural CPMMV transmission by whitefly. CPMMV was also quantified on the three plant replicates of each genotype. Five CPMMV isolates were completely sequenced on all fifteen plants with different genotypes, providing 75 full virus genomes after assembly of PCR sequence blocks. Differences in variability were found between those groups of isolates from transgenic plants to those from conventional ones. With the π, S, K, and Θ-W descriptors, we detected a considerable higher CPMMV variability within transgenic plants in comparison to the virus variability within conventional cultivars in most of the cases. This was the case for all analyzed ORF’s. The ORF’s 2, 3 and 4 were the ones with the highest variability in the genome; at ORF’s 2, 5, and 6, the differences in variability mentioned above are most discernible. Recombination events between isolates happening at the ORF 1 region were detected, as well as at ORF 2 and at ORF 6. Mostly of these were between isolates from transgenic plants. The phylogenetic analysis with ORF 1 sequences of all seventy-five isolates reveals the formation of groups based on host genotypes, and that these groups are most likely grouping near a cluster of isolates from a similar host plant genotype. These could be the result of the direct and specific interactions needed between the viral replicase and the plant. The results of phylogenetic analysis and sequence comparisons with the 3’ region of the viral genome (ORF 2-6), divided the 75 isolates of this study into two groups of CPMMV variants. The pairwise nucleotide differences between isolates from distinct groups ranged from 75 to 85%. The selection tests at some ORF’s give significant evidence that some populations are evolving under a non- random process. The viral accumulation on conventional cultivars did not differ statistically to the accumulation at transgenic plants. In addition, there is no evidence of differences between CPMMV levels at transgenic cultivars that have Pérola as the reccurent parent to those that have the BRS Pontal. The results from this work corroborate with previous studies that indicate the existence of two CPMMV strains naturally distributed in Brazilian production areas. It also confirms the expected high variability potential of this RNA virus; the high variability registered on the newly developed BGMV-resistant transgenic common bean cultivars is also troublesome. The presence of BGMV in mixed infections with CPMMV at conventional cultivars is probably influencing the results of CPMMV variability, but the molecular properties of this interaction is still unknown. These results, in addition to the fact that non-cultivated host plants are distributed along major production areas and may act as viral reservoirs and the known widespread of whiteflies in growing regions of Brazil, make further studies with this pathogen of fundamental importance.

<p>Print mottle is a problem that has been hassling the printing business for a long time. Along with sharpness and correct colour reproduction, absence of print mottle is one of the most important factors of print quality. The possibility to measure the amount of print mottle (reflectance variation) may in many ways facilitate the development of printing methods. Such a measurement model should preferably follow the functions and abilities of the Human Visual System (HVS). </p><p>The traditional model that STFI-Packforsk has developed to measure print mottle uses frequency analysis to find variations in reflectance. However, this model suffers some limitations since is does not perfectly agree with the functions of the HVS and does only measure variations in lightness. A new model that better follows the functions of the HVS has thus been developed. The new model does not only consider variations in lightness (monochromatic) but also variations in colour (chromatic). The new model also puts a higher weight on systematic variations than on random variations since the human eye is more sensitive to ordered structures. Furthermore, the new model uses a contrast sensitivity function that weights the importance of variations in different frequencies. </p><p>To compare the new model with the traditional STFI model, two tests were carried out. Each test consisted of a group of test patches that were evaluated by the traditional STFI model and the new model. The first test consisted of 15 greyscale test patches that originated from conventional flexo and offset presses. The second test consisted of 24 digitally simulated test patches containing colour mottle and systematic mottle. </p><p>The evaluation results in both the traditional and the new model were compared to the results of a visual evaluation carried out using a panel of test persons. The new model produced a result that correlated considerably better with the visual estimation than what the traditional model did.</p>

Print mottle is a problem that has been hassling the printing business for a long time. Along with sharpness and correct colour reproduction, absence of print mottle is one of the most important factors of print quality. The possibility to measure the amount of print mottle (reflectance variation) may in many ways facilitate the development of printing methods. Such a measurement model should preferably follow the functions and abilities of the Human Visual System (HVS). The traditional model that STFI-Packforsk has developed to measure print mottle uses frequency analysis to find variations in reflectance. However, this model suffers some limitations since is does not perfectly agree with the functions of the HVS and does only measure variations in lightness. A new model that better follows the functions of the HVS has thus been developed. The new model does not only consider variations in lightness (monochromatic) but also variations in colour (chromatic). The new model also puts a higher weight on systematic variations than on random variations since the human eye is more sensitive to ordered structures. Furthermore, the new model uses a contrast sensitivity function that weights the importance of variations in different frequencies. To compare the new model with the traditional STFI model, two tests were carried out. Each test consisted of a group of test patches that were evaluated by the traditional STFI model and the new model. The first test consisted of 15 greyscale test patches that originated from conventional flexo and offset presses. The second test consisted of 24 digitally simulated test patches containing colour mottle and systematic mottle. The evaluation results in both the traditional and the new model were compared to the results of a visual evaluation carried out using a panel of test persons. The new model produced a result that correlated considerably better with the visual estimation than what the traditional model did.

No description available.

<p>Coated solid bleached board belongs to the top-segment of paperboards. One important property of paperboard is the printability. In this diploma work a specific print defect, oriented mottle, has been studied in association with Iggesund Paperboard. The objectives of the work were to develop a method for analysis of the dark and light areas of oriented mottle, to analyse these areas, and to clarify the effect from the print, coating and paperboard surface related factors. This would clarify the origin of oriented mottle and predict oriented mottle on unprinted paperboard. The objectives were fulfilled by analysing the areas between the dark halftone dots, the amount of coating and the ink penetration, the micro roughness and the topography. The analysis of the areas between the dark halftone dots was performed on several samples and the results were compared regarding different properties. The other methods were only applied on a limited selection of samples. The results from the study showed that the intensity differences between the dark halftone dots were enhanced in the dark areas, the coating amount was lower in the dark areas and the ink did not penetrate into the paperboard. The other results showed that areas with high transmission corresponded to dark areas, smoother micro roughness, lower coating amount and high topography. A combination of the information from these properties might be used to predict oriented mottle. The oriented mottle is probably an optical phenomenon in half tone prints, and originates from variations in the coating and other paperboard properties.</p>

Print Mottle is perhaps one of the most disturbing factors influencing overall Print Quality. Mottle has traditionally been evaluated by estimating the reflectance variation in the print. Although the amplitude of the reflectance variation is probably the most important aspect of print mottle, other aspects may also influence the perceptibility of mottle. Since the human visual system is optimised to fit the conditions prevailing in its surroundings, it is also important to consider aspects such as mean reflectance factor level, spatial frequency content, structure of the mottle, and colour variations. In this thesis, a new evaluation model for the estimation of print mottle is proposed. The model is best explained as a six-step chain. First, a digital RGB image of the print is acquired with a scanner. The digital RGB image is then calibrated and transformed into the L*a*b* colour space. Next, the three colour components are transformed into the frequency domain by a Fourier transform and the power spectra are calculated. The power spectra are thereafter filtered with respect to the contrast sensitivity functions representing the human eye’s sensitivity to spatial variations in the three colour channels. To account for systematic variations in the sample, the spectra are filtered a second time with texture enhancement filters, which are based on local calculations of chi-square measures in the power spectra. The energy within the visually detectable area of the filtered power spectra is then integrated to obtain a single measure of the variation for each colour component. A single mottle estimate is obtained as the square root of the sum of the squared variation measures for the three components. To acknowledge the influence of mean lightness level on perceived print mottle in a way that agrees with the results presented in Paper I, the mottle estimate obtained is finally multiplied by the sixth root of the mean reflectance factor level. The theoretical foundations of the model are consecutively developed through the first five papers of the thesis. The first paper considers the influence of the mean reflectance level on perceived print mottle. The second and third papers describe the contrast sensitivity filter and the texture enhancement filter applied. The fourth paper compares the new model with other models for print mottle evaluation. The fifth paper extends the grey-scale version of the model into colour. The sixth paper presents the unified model that takes all the mentioned factors into account. To test the model, samples from both simulated sets of prints with various degrees of colour and/or systematic mottle and sets of real prints from various conventional presses were analysed a) visually, b) with traditional print mottle evaluation models, and c) with the new model. Results obtained using the different evaluation models were compared with visual assessments of the sets of prints. In each one of the evaluations the new model was found to be as good as or superior to the traditional print mottle evaluation models in its agreement with visual assessment. The new model is particularly promising in cases where the evaluated prints show colour and/or systematic disturbances. / QC 20101012

<p>Print Mottle is perhaps one of the most disturbing factors influencing overall Print Quality. Mottle has traditionally been evaluated by estimating the reflectance variation in the print. Although the amplitude of the reflectance variation is probably the most important aspect of print mottle, other aspects may also influence the perceptibility of mottle. Since the human visual system is optimised to fit the conditions prevailing in its surroundings, it is also important to consider aspects such as mean reflectance factor level, spatial frequency content, structure of the mottle, and colour variations.</p><p>In this thesis, a new evaluation model for the estimation of print mottle is proposed. The model is best explained as a six-step chain. First, a digital RGB image of the print is acquired with a scanner. The digital RGB image is then calibrated and transformed into the L*a*b* colour space. Next, the three colour components are transformed into the frequency domain by a Fourier transform and the power spectra are calculated. The power spectra are thereafter filtered with respect to the contrast sensitivity functions representing the human eye’s sensitivity to spatial variations in the three colour channels. To account for systematic variations in the sample, the spectra are filtered a second time with texture enhancement filters, which are based on local calculations of chi-square measures in the power spectra. The energy within the visually detectable area of the filtered power spectra is then integrated to obtain a single measure of the variation for each colour component. A single mottle estimate is obtained as the square root of the sum of the squared variation measures for the three components. To acknowledge the influence of mean lightness level on perceived print mottle in a way that agrees with the results presented in Paper I, the mottle estimate obtained is finally multiplied by the sixth root of the mean reflectance factor level.</p><p>The theoretical foundations of the model are consecutively developed through the first five papers of the thesis. The first paper considers the influence of the mean reflectance level on perceived print mottle. The second and third papers describe the contrast sensitivity filter and the texture enhancement filter applied. The fourth paper compares the new model with other models for print mottle evaluation. The fifth paper extends the grey-scale version of the model into colour. The sixth paper presents the unified model that takes all the mentioned factors into account.</p><p>To test the model, samples from both simulated sets of prints with various degrees of colour and/or systematic mottle and sets of real prints from various conventional presses were analysed a) visually, b) with traditional print mottle evaluation models, and c) with the new model. Results obtained using the different evaluation models were compared with visual assessments of the sets of prints. In each one of the evaluations the new model was found to be as good as or superior to the traditional print mottle evaluation models in its agreement with visual assessment. The new model is particularly promising in cases where the evaluated prints show colour and/or systematic disturbances</p>