Fitopatologia - Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11741
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Item Influência de semeaduras sucessivas de feijoeiro na severidade da mancha-angular e ferrugem e perdas na produção(Pesquisa Agropecuária Brasileira, 1999-08) Rodrigues, Fabrício de Ávila; Fernandes, Jonas Jäger; Martins, MaurícioA mancha-angular (Phaeoisariopsis griseola) e a ferrugem (Uromyces appendiculatus) são algumas das mais prejudiciais doenças do feijoeiro na região do Triângulo Mineiro, Minas Gerais. O objetivo deste estudo foi determinar a influência das semeaduras sucessivas na severidade da mancha-angular e da ferrugem, bem como as perdas na produção em decorrência dessas doenças. Os experimentos foram conduzidos em condições de campo, nas safras outono-inverno (1994) e das águas (1994/95), cada uma com três semeaduras sucessivas de feijão. A severidade da mancha-angular e da ferrugem aumentou significativamente da primeira para a terceira semeadura, atingindo nível mais elevado na última. As semeaduras anteriores foram a fonte de inóculo para os cultivos subseqüentes. Aplicações de fungicida foram eficientes no controle das doenças, permitindo um aumento significativo da produção de grãos, quando comparado com o controle. A mancha-angular apresentou maior incidência no outono-inverno e nas águas, e a ferrugem, apenas no outono-inverno. Nessas safras as condições climáticas (temperatura e umidade relativa) favoreceram a evolução das doenças, resultando num aumento da severidade. Houve uma correlação negativa e altamente significativa entre a severidade da mancha-angular e da ferrugem com a produção de grãos nas duas safras.Item Culinary and nutritional quality of common bean lines with Carioca grain type and interaction with environments(Revista Ceres, 2017-03) Pereira, Helton Santos; Alvares, Renata Cristina; Melo, Leonardo Cunha; Costa, Antônio Félix da; Carvalho, Hélio Wilson Lemos deThe objectives of this work were to study the genetic variability and the interaction between genotypes and environments for cooking time and protein content of bean grains as well as to identify elite lines of Carioca grain type with short cooking time, high protein content and high adaptability and stability for these two traits. Sixteen experiments were conducted in a complete randomized block design with three replications during the rainy, dry and winter seasons, in Goiás, Distrito Federal, Pernambuco, Sergipe, Bahia and Paraná States, in 2009 and 2010. Each trial was composed by 16 elite lines of Carioca grain type and the data of cooking time and protein content were obtained. Data were submitted to analysis of variance and to stability and adaptability analysis, according to the methodology proposed by Annichiarico. Genetic variability was found for cooking time and for protein content among Carioca common bean elite lines; however, for protein content this variability is lower. The environmental effect is important for the expression of these traits and is larger than the genetic effect. The interaction between genotypes and environments is important for cooking time and for protein content of common beans. The lines CNFC 11951 and CNFC 11962 presents short cooking time, high protein content and high stability and adaptability for both traits.Item Phosphites attenuate Sclerotinia sclerotiorum-induced physiological impairments in common bean(Acta Physiologiae Plantarum, 2018-11) Fagundes-Nacarath, I. R. F.; Debona, D.; Brás, V. V.; Silveira, P. R.; Rodrigues, F. A.Phosphites, marketed as foliar fertilizers and resistance activators, have been shown to be useful for the control of diseases in many profitable crops. Despite the importance of white mold, caused by Sclerotinia sclerotiorum, to reduce common bean yield, knowledge of the phosphites´ effect on disease control at the physiological level is still missing. In this study, the leaf gas exchange and chlorophyll a fluorescence parameters variable-to-maximum chlorophyll a fluorescence ratio (Fv/Fm), photochemical yield [Y(II)], yield for dissipation by down-regulation [Y(NPQ)], yield for non-regulated dissipation [Y(NO)], and electron transport rate (ETR) as well as the concentrations of photosynthetic pigments in common bean plants that were sprayed with zinc (Zn) or copper (Cu) phosphites and challenged or not with S. sclerotiorum were determined. Based on the in vitro assays, Zn and Cu phosphites inhibited fungal mycelial growth in a dose-dependent manner, but the Cu phosphite showed to be more fungitoxic. Lesion area and white mold severity were reduced by Zn and Cu phosphites, but the Zn phosphite was more effective. Fungal infection dramatically decreased the values of net carbon assimilation rate, stomatal conductance to water vapor and transpiration rate on non-sprayed plants. Increases in internal CO2 concentration indicated that fungal-induced photosynthetic impairments were chiefly governed by biochemical limitations, but these impairments were greatly abrogated in the Zn and Cu phosphite-sprayed plants. Similarly, the photochemical dysfunctions stemmed from S. sclerotiorum infection were limited in the Zn and Cu phosphite-sprayed plants. Concentrations of chlorophyll a + b and carotenoids decreased on inoculated plants, but lower reductions were recorded on Zn and Cu phosphites-sprayed plants. In conclusion, the potential of Zn and Cu phosphites in attenuate the S. sclerotiorum-induced physiological impairments in common bean leaflets was demonstrated and may be an effective mean for managing this disease under field conditions.Item A set of standard area diagrams to assess white mold severity on the leaflets of common beans(Crop Protection, 2018-12) Fagundes-Nacarath, Inaia Rhavene Freire; Debona, Daniel; Novaes, Maria Izabel Costa; Rodrigues, Fabrício ÁvilaThe fungus Sclerotinia sclerotiorum is the major pathogen affecting common beans yield worldwide and an adequate disease quantification is demanded in some trials. However, a set of standard area diagrams (SADs) to aid visual assessment of severity of white mold (SWM) is lacking. This study developed SADs consisting of eight color images of diseased leaflets with severity values that ranged from 0.4 to 53.7%. Twenty raters [10 experienced (ER) and 10 inexperienced (IR)] validated the SADs by assessing the same set of 50 images twice, the first without SADs and the second using it as an aid. The SADs significantly improved both accuracy and precision for IR as evidenced by increases from 0.86 to 0.98 in the coefficients of bias (Cb) from 0.93 to 0.98 in correlation coefficient (r) and from 0.86 to 0.96 in overall agreement [Lin's concordance correlation coefficients (ρc)] without and with SADs, respectively, whereas for ER only precision (r) was improved by SADs. The SWM estimates were also more reliable because inter-rater reliability (coefficient of determination, R2) was significantly increased for both ER and IR by using SADs. Therefore, the SADs presented is thought to be a valuable tool to provide accurate, precise and reliable estimates of the SWM on common bean leaflets in epidemiological studies, evaluation of disease control methods, assessment of aggressiveness of pathogen isolates, disease resistance and other types of surveys regarding the common beans-S. sclerotiorum interaction.Item Biochemical responses of common bean to white mold potentiated by phosphites(Plant Physiology and Biochemistry, 2018-11) Fagundes-Nacarath, I. R. F.; Debona, D.; Oliveira, A. T. H.; Hawerroth, C.; Rodrigues, F. A.Considering that the mechanisms for phosphite-afforded disease control remain elusive, this study investigated whether zinc (Zn) and copper (Cu) phosphites could possible potentiate common bean resistance to white mold, caused by Sclerotinia sclerotiorum, through the stimulation of biochemical defence responses. Lesion area and disease severity were decreased by phosphites spray, but Zn phosphite outcompeted Cu phosphite. Histopathological observations revealed fewer fungal hyphae and less collapse of the mesophyll cells in the Zn and Cu phosphite-sprayed plants compared to water-sprayed ones. The S. sclerotiorum-triggered accumulation of reactive oxygen species, oxalic acid (a fungal secreted toxin) and malondialdehyde (an indicator of cellular damage) were constrained as a result of Zn and Cu phosphites spray. Activities of antioxidant enzymes (superoxide dismutase, peroxidase, ascorbate peroxidase and glutathione-S-transferase at 12 h after inoculation (hai) and catalase at 60 and 84 hai) were higher for Zn and Cu phosphites-sprayed plants than for water-sprayed ones. Activities of defence-related enzymes chitinase (CHI) at 12 hai, β-1,3-glucanase (GLU) and polyphenoloxidase (PPO) were higher at 12–84 hai for Zn, and Cu phosphites sprayed plants, phenylalanine ammonia-lyase at 36–84 hai for the Zn phosphite sprayed ones, CHI at 12–36 hai, GLU at 12–60 hai, PPO at 36 hai and PAL and lipoxygenase at 12 hai for the Cu phosphite sprayed ones upon inoculation with S. sclerotiorum relative to their water-sprayed counterparts. Concentrations of total soluble phenols and lignin-thioglycolic acid derivatives were not affected by Cu phosphite spray on infected plants but were higher and lower, respectively, for Zn phosphite sprayed plants at 60 hai compared to water-sprayed ones. Taken together, the findings from the present study shed light on the biochemical defence mechanisms involved in the Zn and Cu phosphites-mediated suppression of white mold in common bean.Item Oxalic acid-mediated biochemical and physiological changes in the common bean-Sclerotinia sclerotiorum interaction(Plant Physiology and Biochemistry, 2018-08) Fagundes-Nacarath, I. R. F.; Debona, D.; Rodrigues, F. A.The success of Sclerotinia sclerotiorum infection relies mainly on the production of the non-host selective toxin named oxalic acid (OA). This toxin is known to play multiple roles in a host infected by the fungus, but its effect on photosynthesis and the antioxidant system of common bean plants remain elusive. Therefore, we performed detailed analysis of leaf gas exchange, chlorophyll a fluorescence, activities of antioxidant enzymes, concentrations of reactive oxygen species and photosynthetic pigments to investigate the OA's role during the S. sclerotiorum pathogenesis. To achieve this goal, common bean plants were sprayed with water or with oxalic acid (referred to as –OA and +OA plants, respectively) and either non-challenged or challenged with a wild-type (WT) or an OA-defective mutant (A4) of S. sclerotiorum. Irrespective of OA spray, the WT isolate was more aggressive than the A4 isolate and spraying OA increased OA concentration in the leaflets as well as the aggressiveness of both isolates. Biochemical limitations were behind S. sclerotiorum-induced photosynthetic impairments notably for the +OA plants inoculated with the WT isolate. Inoculated plants were not able to fully capture and exploit the collected energy due to the degradation of photosynthetic pigments. Photoinhibition of photosynthesis and photochemical dysfunctions were potentiated by OA. Higher activities of superoxide dismutase, peroxidase and ascorbate peroxidase besides reductions on catalase activity were noticed for plants inoculated with the WT isolate. OA was able to counteract most of the increases in the activities of antioxidant enzymes thereby increasing the generation of superoxide and hydrogen peroxide and the concurrent damage to the membranes of host cells as evidenced by the high malondialdehyde concentration. In conclusion, OA was found to enhance biochemical limitations to photosynthesis, photochemical dysfunctions and oxidative stress in the leaflets of common bean plants infected by S. sclerotiorum.Item Effect of kind and method of fungicidal treatment of bean seed on infections by the VA-mycorrhizal fungus Glomus macrocarpum and by the pathogenic fungus Fusarium solani(Plant and Soil, 1991-04) Gonçalves, E. J.; Muchovej, J. J.; Muchovej, Rosa M. C.To test the effect of seed treatment with fungicides on the development of mycorrhizal fungi, bean seeds were treated with fungicide dry or vehicled in the organic solvents, ethanol or dichloromethane and then planted in soil inoculated with the mycorrhizal fungus Glomus macrocarpum and/or the plant pathogenic fungus Fusarium solani. Measurements were made at 4 day intervals, to assess the presence of mycorrhizae or disease in the roots as well as top dry weight, root fresh weight and root length. Fungicidal seed treatment did not affect the initial occurrence of mycorrhizae, number of spores of G. macrocarpum in the soil or root length. Fresh weights of roots and dry weights of tops were greater in the presence of the mycorrhizal fungus. The onslaught of symptoms by F. solani was significantly retarded by treatment with fungicides plus mycorrhizal fungi or fungicides plus organic solvents.Item Molecular diversity in Fusarium oxysporum isolates from common bean fields in Brazil(European Journal of Plant Pathology, 2018-04-16) Silva, Lucas Fagundes; Cruz, Andre Freire; Sousa, Tiago Vieira; Nicoli, Alessandro; Paula Junior, Trazilbo Jose de; Caixeta, Eveline Teixeira; Zambolim, LaercioThe common bean (Phaseolus vulgaris L.) is widely cultivated in Brazil and is known as a very important crop for families in this country. Fusarium wilt severely harms common beans and has become a big issue for this crop. In order to assist the breeding programs that target resistance to this disease, the evaluation of genetic diversity of the pathogen and its molecular characterization are crucial. Thus, the present goal was to identify Fusarium isolates obtained from several places in Brazil using molecular tools; select molecular markers for these isolates; and analyze their diversity. All of isolates were molecularly identified as Fusarium oxysporum f. sp. phaseoli (Fop). By using seven selected SSR markers, the results of diversity obtained by the dendrogram and the Bayesian analysis formed four groups where a large diversity of this fungus was found within each state. However, the groups were more homogenous according to the collection source and the pathogenicity test. More specifically, group 2 was composed of the most virulent strains and originated from Minas Gerais State – UFV, and group 3 was mostly composed by isolates from Goias state. Group I was also more diverse in terms of location and virulence. The overall results indicated a positive correlation between Fusarium diversity and its virulence to common bean. Furthermore, the use of these markers was effective in molecular identification and in detecting polymorphism within F. oxysporum f. sp. phaseoli.Item Single nucleotide polymorphism discovery in common bean(Molecular Breeding, 2011-09-13) Souza, Thiago Lı́vio P. O.; Barros, Everaldo G. de; Bellato, Claudia M.; Hwang, Eun-Young; Cregan, Perry B.; Pastor-Corrales, Marcial A.Single nucleotide polymorphisms (SNPs) were discovered in common bean (Phaseolus vulgaris L.) via resequencing of sequence-tagged sites (STSs) developed by PCR primers previously designed to soybean shotgun and bacterial artificial chromosome (BAC) end sequences, and by primers designed to common bean genes and microsatellite flanking regions. DNA fragments harboring SNPs were identified in single amplicons from six contrasting P. vulgaris genotypes of the Andean (Jalo EEP 558, G 19833, and AND 277) and Mesoamerican (BAT 93, DOR 364, and Rudá) gene pools. These genotypes are the parents of three common bean recombinant inbred line mapping populations. From an initial set of 1,880 PCR primer pairs tested, 265 robust STSs were obtained, which could be sequenced in each one of the six common bean genotypes. In the resulting 131,120 bp of aligned sequence, a total of 677 SNPs were identified, including 555 single-base changes (295 transitions and 260 transversions) and 122 small nucleotide insertions/deletions (indels). The frequency of SNPs was 5.16 SNPs/kb and the mean nucleotide diversity, expressed as Halushka’s theta, was 0.00226. This work represents one of the first efforts aimed at detecting SNPs in P. vulgaris. The SNPs identified should be an important resource for common bean geneticists and breeders for quantitative trait locus discovery, marker-assisted selection, and map-based cloning. These SNPS will be also useful for diversity analysis and microsynteny studies among legume species.Item Reação de cultivares e linhagens de feijão a Murcha-de-Fusarium(Revista Ceres, 2002-02-06) Marrara, Leonardo Oliveira; Vieira, Rogério Faria; Pereira, José MaurícioA murcha-de-fusarium, causada por Fusarium oxysporum f. sp. phaseoli, b doença séria em muitas areas produtoras de feijão do Brasil, especialmente nas irrigadas. A patogenicidade do isolado FOP 46 em 12 cultivares/linhagens de feijão foi avaliada em casa de vegetação. Turmalina e Rosinha mostraram-se suscetiveis, enquanto Paola, Vi. 13-8-3, EEP 558, CF 880065, Vi. 12-1-2, Vi. 343-1, Vi. 10-2-1, Vi. I6-3-3, Carnaval e Novirex foram resistentes.