Correlation study of resistance components in the selection of Capsicum genotypes resistant to the fungus Colletotrichum gloeosporioides.

Anthracnose is among the major diseases of the Capsicum culture. It is caused by different species of the genus Colletotrichum, which may result in major damages to the cultivation of this genus. Studies aiming to search for cultivars resistant to diseases are essential to reduce financial and agricultural losses. The objective of this study was to evaluate the correlation between the variables analyzed to select Capsicum genotypes resistant to the fungus Colletotrichum gloeosporioides. The experimental design was completely randomized blocks with three replications, 88 treatments, four ripe fruits, and four unripe fruits per replication. Accessions of Capsicum from the Germplasm Active Bank of Universidade do Estado de Mato Grosso (UNEMAT) were evaluated as for resistance to the fungus. Fruits were collected from each plot and taken to the laboratory for disinfestation. A lesion was performed in the middle region of the fruit using a sterile needle, where a spore suspension drop, adjusted to 106 spores/mL, was deposited. An ultrapure water drop was deposited into control fruits. The fruits were placed in humid chambers, and the evaluation was performed by measuring the diameter and the length of lesions using a caliper for 11 days. After data were obtained, analyses of variance, correlation, and path analysis were performed using the GENES software and R. According to the likelihood-ratio test, the effects of genotypes (G), fruit stage (F), and its interaction (G x F) were significant (P < 0.05). There were differences between the magnitudes of genotype correlations according to fruit stage. Different variables must be taken into account for an indirect selection in this culture in function of fruit stage since the variable AUDPC is an important criterion for selecting resistant accessions. We found through the path analysis that the variables DULRD and DULRL exerted the greatest effects on AUDPC.

Morphological descriptors and ISSR molecular markers in the evaluation of genetic variability of Tectona grandis genotypes.

This study aimed to evaluate the genetic variability of the teak germplasm bank, using morphological traits and inter-simple sequence repeat molecular markers. Thirty clones were evaluated in a randomized complete block design with three replicates, and each plot was composed of three plants. A joint analysis of quantitative and qualitative variables was performed using the Gower algorithm. Quantitative, qualitative, and molecular variables were analyzed simultaneously using the Ward-MLM procedure. There is genetic variability among the 30 teak genotypes studied, considering the quantitative, qualitative, and molecular variables by the Ward-MLM statistical procedure. Morphological traits used proved to be efficient for the study of genetic variability; however, it was not possible to compose a descriptor table for clonal teak genotypes based on the traits evaluated. The Gower method was efficient in discriminating the groups, demonstrating that the simultaneous analysis of qualitative and quantitative data is feasible and can allow greater efficiency in the knowledge of the variability among teak genotypes. The genotype 22 showed to be the most divergent compared to the other genotypes, except for the cluster of genotypes by the UPGMA method based on the Gower distance obtained by the Ward-MLM procedure, which formed a group with genotypes 9 and 30, in the morphological and molecular analyses and was grouped alone.

Morphoagronomic and molecular profiling of Capsicum spp from southwest Mato Grosso, Brazil.

The genus Capsicum ranks as the second most exported vegetable in Brazil, which is also considered to be a center of diversity for this genus. The aim of this study was to rescue genetic variability in the genus Capsicum in the southwest region of Mato Grosso, and to characterize and estimate the genetic diversity of accessions based on morphoagronomic descriptors and inter-simple sequence repeat molecular markers. Data were obtained following the criteria of the International Plant Genetic Resources Institute, renamed Bioversity International for Capsicum. Data were analyzed using different multivariate statistical techniques. An array of binary data was used to analyze molecular data, and the arithmetic complement of the Jaccard index was used to estimate the genetic dissimilarity among accessions. Six well-defined groups were formed based on the morphological characterization. The most divergent accessions were 142 and 126, with 125 and 126 being the most similar. The groups formed following agronomic characterization differed from those formed by morphological characterization, and there was a need to subdivide the groups for better distinction of accessions. Based on molecular analysis, accessions were divided into two groups, and there was also a need to subdivide the groups. Based on joint analysis (morphological + agronomic + molecular), six groups were formed with no duplicates. For all groups, the cophenetic correlation coefficient was higher than 0.8. These results provide useful information for the better management of the work collection. All correlations between the combined distance matrix were significant by the Mantel test.

Use of Self-Matching to Control for Stable Patient Characteristics While Addressing Time-Varying Confounding on Treatment Effect: A Case Study of Older Intensive Care Patients.

Exposure-crossover design offers a non-experimental option to control for stable baseline confounding through self-matching while examining causal effect of an exposure on an acute outcome. This study extends this approach to longitudinal data with repeated measures of exposure and outcome using data from a cohort of 340 older medical patients in an intensive care unit (ICU). The analytic sample included 92 patients who received ≥1 dose of haloperidol, an antipsychotic medication often used for patients with delirium. Exposure-crossover design was implemented by sampling the 3-day time segments prior (Induction) and posterior (Subsequent) to each treatment episode of receiving haloperidol. In the full cohort, there was a trend of increasing delirium severity scores (Mean±SD: 4.4±1.7) over the course of the ICU stay. After exposure-crossover sampling, the delirium severity score decreased from the Induction (4.9) to the Subsequent (4.1) intervals, with the treatment episode falling in-between (4.5). Based on a GEE Poisson model accounting for self-matching and within-subject correlation, the unadjusted mean delirium severity scores was -0.55 (95% CI: -1.10, -0.01) points lower for the Subsequent than the Induction intervals. The association diminished by 32% (-0.38, 95%CI: -0.99, 0.24) after adjusting only for ICU confounding, while being slightly increased by 7% (-0.60, 95%CI: -1.15, -0.04) when adjusting only for baseline characteristics. These results suggest that longitudinal exposure-crossover design is feasible and capable of partially removing stable baseline confounding through self-matching. Loss of power due to eliminating treatment-irrelevant person-time and uncertainty around allocating person-time to comparison intervals remain methodological challenges.

An Empirical Method of Detecting Time-Dependent Confounding: An Observational Study of Next Day Delirium in a Medical ICU.

Longitudinal research on older persons in the medical intensive care unit (MICU) is often complicated by the time-dependent confounding of concurrently administered interventions such as medications and intubation. Such temporal confounding can bias the respective longitudinal associations between concurrently administered treatments and a longitudinal outcome such as delirium. Although marginal structural models address time-dependent confounding, their application is non-trivial and preferably justified by empirical evidence. Using data from a longitudinal study of older persons in the MICU, we constructed a plausibility score from 0 - 10 where higher values indicate higher plausibility of time-dependent confounding of the association between a time-varying explanatory variable and an outcome. Based on longitudinal plots, measures of correlation, and longitudinal regression, the plausibility scores were compared to the differences in estimates obtained with non-weighted and marginal structural models of next day delirium. The plausibility scores of the three possible pairings of daily doses of fentanyl, haloperidol, and intubation indicated the following: low plausibility for haloperidol and intubation, moderate plausibility for fentanyl and haloperidol, and high plausibility for fentanyl and intubation. Comparing multivariable models of next day delirium with and without adjustment for time-dependent confounding, only intubation's association changed substantively. In our observational study of older persons in the MICU, the plausibility scores were generally reflective of the observed differences between coefficients estimated from non-weighted and marginal structural models.

Fungos endofíticos associados a plantas medicinais / Endophytic fungi associated with medicinal plants

Com a utilização de plantas medicinais em infusões, xaropes, tinturas, ungüentos, dentre outras formas, pressupõe-se que fungos endofíticos, presentes no interior das plantas, mas sem causar doença, possam tornar-se um componente destes produtos, principalmente quando utilizados in natura. Além disso, os fungos endofíticos podem também produzir substâncias tóxicas aos usuários ou mesmo alterar o metabolismo vegetal, modificando a composição e as propriedades medicinais, assim como, a qualidade do produto armazenado e comercializado. Neste sentido, objetivou-se isolar e identificar a flora fúngica endofítica de onze espécies medicinais escolhidas ao acaso. Obtiveram-se culturas-puras dos fungos Phomopsis, Colletotrichum, Pestalotia, Trichoderma, Fusarium, Nigrospora e Glomerella ocorrendo endofiticamente em Plectranthus barbatus, Vernonia condensata, Pfaffia paniculata, Foeniculum vulgare, Cymbopogon citratus, Cymbopogon nardus, Cordia curassavica, Maytenus ilicifolia, Punica granatum, Morus nigra e Bauhinia forficata. As espécies vegetais em que se identificaram o maior número de fungos endofíticos foram Vernonia condensata, Punica granatum e Morus nigra. Todos os fungos recuperados neste trabalho apresentaram características estritamente endofíticas, não manifestando patogenicidade nas espécies hospedeiras. Dentre os fungos detectados, especial atenção deve ser dada ao gênero Fusarium, uma vez que inúmeras espécies deste gênero são conhecidas produtoras de micotoxinas e constituem-se em importantes patógenos pós-colheita.

With the use of medicinal plants in infusions, syrups, dyes, unguents, among other forms, it is expected that endophytic fungi, present inside the plants but not causing diseases, become components of these products, especially when used in natura. In addition, endophytic fungi can produce toxic substances to the users or even modify the plant metabolism, altering the medicinal composition and properties, as well as the quality of the stored and commercialized product. Therefore, the aim of this study was to isolate and identify the endophytic flora from eleven randomly chosen medicinal species. Pure cultures were obtained from the fungi Phomopsis, Colletotrichum, Pestalotia, Trichoderma, Fusarium, Nigrospora and Glomerella endophytically occurring in Plectranthus barbatus, Vernonia condensata, Pfaffia paniculata, Foeniculum vulgare, Cymbopogon citratus, Cymbopogon nardus, Cordia curassavica, Maytenus ilicifolia, Punica granatum, Morus nigra and Bauhinia forficata. The plant species that presented the highest number of endophytic fungi were Vernonia condensata, Punica granatum and Morus nigra. All fungi recovered in this study showed strictly endophytic features, not manifesting pathogenicity in their host species. Among the detected fungi, special attention must be given to the genus Fusarium, since a wide range of species of this genus are known to produce mycotoxins and constitute important post-harvest pathogens.