Conditions Of Southern Brazil Research Articles

Growth and yield of Brazilian potato cultivars

The analysis of plant growth of cultivars is useful for understanding the dynamics of accumulation and partition of photoassimilates during the crop cycle, and this information is important for the crop management of each cultivar. The objective of this study was to evaluate potato cultivars BRS Ana, BRSIPR Bel, BRS Clara, BRS F63 (Camila) and Macaca for growth and yield, under subtropical climatic conditions of Southern Brazil. Plant samples were collected every 20 days, beginning 40 days after planting (DAP), totaling five collections, and physiological growth indexes and the dry mass partitioning to plant organs were estimated. ‘BRSIPR Bel’ showed the fastest development of assimilatory system. ‘BRS Ana’ had the most vigorous plants and the largest leaf area, reaching the leaf area index 4.0 at 70 DAP. ‘BRSIPR Bel’ e ‘BRS Ana’ had the highest dry mass yield, 214 g and 206 g of dry mass plant-1, respectively. ‘BRS F63’ (Camila) and ‘BRSIPR Bel’ presented earlier tuberization and were the most efficient cultivars in the partitioning of dry mass to tubers, with the highest coefficient of dry mass partitioning to tubers estimated between 40 and 64 DAP. These two cultivars also showed the highest yield of marketable tubers.

Relationships between nutrients in the soil and nutritional status of Pinus taeda stands in southern Brazil

The characterization of nutrients availability in the soil and its relationship with nutritional status and productivity of Pinus taeda stands in southern Brazil is still of concern due the lack of research on this subject. We compared different methods to evaluate P, K, Ca, and Mg in the soil and in plant tissues. We performed the evaluations in six paired plots (control and fertilized) located on different soils conditions in southern Brazil. Availability of nutrients in the soil was obtained after extractions of soil solutions with the extractors Mehlich I (P, K), KCl 1 mol L−1 (Ca, Mg), and 1 % citric acid (P, K, Ca, Mg). Foliar and wood samples were collected to determine the P, K, Ca, and Mg contents in the trees’ tissues. The mean annual increment (MAI) of each plot was obtained from the annual inventories of the P. taeda stands. The contents of P, K, Ca, and Mg in the soil followed similar trends for the different extractors tested, with higher contents of Ca and Mg in the fertilized plots. No differences for P and K in the soil were observed between control and fertilized plots for both methods applied. The fertilized plots showed increase for Ca and Mg in the wood tissues but not in the needles. Positive correlation between wood and needle tissues was observed only for the P content. No correlation between the nutrient contents in the needles and in the soil was observed. But we found a positive correlation between the nutrient contents in the wood and in the soil, mainly for the 1% citric acid method. No correlation was found between the nutrients in the plant tissues and the productivity of Pinus taeda. Our results improved the knowledge concerning the nutrient dynamics in P. taeda stands in southern Brazil showing that citric acid is a good extractor for P, K, Ca, and Mg in the soil, and that determination of nutrients in the wood tissues is a potential method for nutritional diagnosis of P. taeda.

Nitrogen and carbon stocks in sandy soil cultivated with corn subjected to 17 years of animal manure and mineral fertilizer application

Animal manure can be used as a source of nutrients in cropping systems throughout the world. However, in subtropical climates, the impacts of animal manure application over multiple years on crop productivity and on the total organic carbon (TOC) and total nitrogen (TN) stocks in the soil profile are not well understood. In this study, we aimed to evaluate how animal manure application carried out over more than 17 years can impact corn productivity and TOC and TN stocks in different soil layers. This long-term study was conducted from 2004 to 2021 under no-till conditions in southern Brazil. The treatments included pig slurry (PS), cattle slurry (CS), pig deep litter (PDL), mineral fertilizer (NPK) and a control (no fertilizer application). To determine soil TOC and TN stocks, soil samples were collected from the 0.00–0.10, 0.10–0.20, 0.20–0.30, 0.30–0.40 and 0.40–0.50 m layers in December 2008, 2012, 2016 and 2020. Corn productivity was evaluated for the 2008/09, 2012/13, 2016/17, and 2020/21 crops. The highest yields and TOC and TN stocks were observed in soils with pig deep litter and cattle slurry application. In the sandy soil under a no-till system after 26 animal manure applications over 17 years, the highest TOC and TN stocks were observed in the 0.00–0.10 m layer. On average, the TOC stocks obtained for the 0.00–0.10 m layer were 11.21, 14.88, 15.82, 22.59 and 15.16 Mg ha−1 for the control, PS, CS, PDL and NPK treatments, respectively. The soil TN stocks in the 0.00–0.10 m layer were 1.06, 1.40, 1.65, 2.03 and 1.43 Mg ha−1 for the control, PS, CS, PDL and NPK treatments, respectively. The application of pig deep litter to the soil over 17 years resulted in a notable increase in TOC and TN levels, playing a crucial role in increasing the productivity of maize crops.

Evaluation of chickpea genotypes in Cerrado conditions in the South of the state of Tocantins

The chickpeas (Cicer arietinum L.) has potential for cultivation in the Brazilian cerrado region, its sowing supplies both the domestic market and exports, bringing benefits to the economy. In this context, the objective of this study was to evaluate morphophysiological and yield parameters in six genotypes of chickpeas with different genetic basis, which make it possible to select materials suitable for commercial cultivation under the conditions of the cerrado in the south of the state of Tocantins. Six treatments were used to carry out the experiment, each one characterized by one of the following: BRS Cícero; BRS Aleppo; BRS Khalifa; BRS Cristalino; Jamu 96 and BRS Toro. To define the best genotypes, morphophysiological characteristics of the crop were evaluated, namely: grain yield, weight of a thousand grains, plant height, number of days until flowering, number of days until maturation, chlorophyll a and b index, internal concentration of CO2, photosynthesis, stomatal conductance and transpiration. The cultivation of chickpeas in the cerrado is viable for the region. The Jamu 96 genotype stands out among the others, in the main morphophysiological characteristics, being the one that obtained the highest production averages. The genotypes BRS Cícero, BRS Aleppo and BRS Khalifa showed potential for improvement in production, due to their thousand-grain weight being similar to Jamu 96, making evident the need for genetic improvement in order to obtain genotypes more adapted to the soil and climate conditions of southern Brazil. Tocantins, making them more adapted to the region and thus increasing the production potential.

Little Leaf Disease and Pine Wood Nematodes Disrupt Anatomical and Physiological Traits of Pinus taeda at Subtropical Conditions in Southern Brazil

Little Leaf Disease and Pine Wood Nematodes Disrupt Anatomical and Physiological Traits of Pinus taeda at Subtropical Conditions in Southern Brazil

Performance of ‘Gala Select’ and ‘Fuji Suprema’ grafted on Geneva series rootstocks under fallow land and replanting conditions in southern Brazil

BackgroundRootstocks less vigorous are among the most crucial management techniques to modernize fruit cultivation. Replanting with fallow land has become necessary due to a lack of land to establish new orchards. ObjectiveThe aim of this study is to determine the effect of various rootstocks of the American Geneva® series on the yield performance of the apple (Malus domestica Borkh) cultivars ‘Gala Select’ and ‘Fuji Suprema’ under replanting conditions in southern Brazil. Methods: After two years of fallow land, the experiments were initiated in 2017 and conducted during the 2018, 2019, 2020, and 2021 growing seasons in Painel and Caxias do Sul municipalities at the Santa Catarina and the Rio Grande do Sul State, respectively. The ‘Gala Select’ and ‘Fuji Suprema’ were grafted onto the G.202, G.814, G.210, and G.213 Geneva series rootstocks in a tall spindle training system using a randomized complete block design with four replicates. Principal component analysis (PCA) was used to assess the interrelationship among the variable's vigor, productivity, and fruit quality. ResultsThe PCA result showed significant differences in vigor, productivity, and fruit quality when the G.210 and G.213 and G.814 and G.213 Geneva series rootstocks were used in combination with Gala Select and Fuji Suprema cultivars, respectively. The PCA analysis clustered all cultivar/rootstock combinations into two groups, based on their vigor and productivity and the yield performance and fruit quality data, that differed significantly among combinations and regions. The ‘Gala Select’/G.202 and ‘Fuji Suprema’/G.213 combinations were less vigorous than the ‘Gala Select’/G.210 and ‘Fuji Suprema’/G.814 combinations. However, ‘Gala Select’/G.210 (semi-dwarfing) and G.213 (dwarfing) are the combinations with high yield performance, productive efficiency and fruit quality, being more reliable to the producer, and less vigorous, resulting in lower labor costs under replating conditions, with two years of fallow land, from 2018 until 2021 growing seasons.

Phenology and phyllochron of seven strawberry cultivars grown in substrate and greenhouse in the Brazilian subtropics

Knowing the phenology and phyllochron of strawberry cultivars allows the establishment of phytotechnical managements aimed at enhancing the productive chain of this horticultural crop. Thus, the objective of this work was to investigate whether phenology and phyllochron differ among strawberry cultivars grown in substrate and greenhouse. The treatments were seven strawberry cultivars arranged in a randomized block design, with four replications. Leaf emission rate, occurrence and duration of phenological stages were evaluated. ‘Fronteras’ was considered the earliest to start fruiting, as it had the lowest phyllochron value, while ‘Albion’ was the latest. Through multivariate analysis, the formation of two groups among strawberry cultivars was observed according to their phenological characteristics. Group 1 gathered the five strawberry cultivars classified as having neutral-days in terms of flowering and group 2 was composed of the two short-day cultivars. It is concluded that, under the cultivation conditions of southern Brazil, ‘Fronteras’ is the earliest to start the fruit harvest, provided it is transplanted in May, and ‘Albion’ is the latest. Neutral-day cultivars have a shorter transplant cycle until the beginning of harvest, while short-day cultivars require a longer interval for this transition, with a prolonged vegetative period.

Legume winter cover crop (Persian clover) reduces nitrogen requirement and increases grain yield in specialized irrigated hybrid rice system

In high-yield irrigated rice systems, options for legume cover crops with the capacity for biological nitrogen (N) fixation in the period between harvest have been sought. However, options are limited due to excess water and low oxygen level in the soil. The persian clover (Trifolium resupinatum) is an exception as it is a promising species due to its adaptation to waterlogged soils. Thus, the objective of this work was to evaluate accumulated nitrogen in the legume, soil mineral and microbial N levels and the response of a rice hybrid established in succession to persian clover during four growing seasons in subtropical conditions in southern Brazil. The field experiment was carried out during four crop seasons in a 2 × 4 factorial, with two conditions of soil cover, fallow and legume (persian clover) under four levels of N (0, 60, 120 and 180 kg N ha−1). It was observed that the cultivation of Persian clover increased the availability of mineral and microbial N in the soil by 35% and 6.5%, respectively. There was a 14.1% reduction in the optimal nitrogen rate in the rice hybrid. The grain yield of rice grains using persian clover in winter is 7.8% higher in relation to fallow, with the greatest difference between clover and fallow at the lowest N rates (0 e 60 kg ha−1). Thus, persian clover is a promising legume to be used in the period between harvest in hydromorphic soils cultivated with irrigated rice in subtropical conditions.

Use of microstructural characteristics of pollen and pistil to identify olive cultivars in Southern Brazil

The olive crop has a large diversity in cultivars around the world, whose identification have been based on leaf, stem or fruit traits. However, these traits may be influenced by the environment, which has led to the misidentification of cultivars. The variability of the pistil and pollen structure under electron scanning and light microscopy were studied using the cultivars 'Arbequina', 'Arbosana', 'Frantoio', 'Koroneiki', 'Manzanilla de Sevilla' and 'Picual', cultivated in Southern Brazil. The aim was to find unique patterns for their identification. This type of study has not been carried out in the conditions of Southern Brazil, where the identification of commercial cultivars sometimes is complex and confusing. There were significant differences in the variables, showing uniformity within each cultivar in different locations. The principal component analysis indicated a separation of cultivars according to similarities or micromorphological differences in the pollen wall, area of the lumen and the structural elements of the tectum. For the analysis of the pistil, the separation was even clearer, each cultivar individually forming a cluster, using as characters the length of the style in contrast to the length, width and area of the stigma. This evidenced little variation among individuals within the same cultivar. The information provided can contribute to the individual identification of very close olive tree cultivars in the conditions of Southern Brazil.

Nitrogen Use Efficiency and Yield of Wheat Genotypes Affected by Nitrogen Fertilizing and Environmental Conditions in Southern Brazil

Nitrogen Use Efficiency and Yield of Wheat Genotypes Affected by Nitrogen Fertilizing and Environmental Conditions in Southern Brazil

Rotational and selective protocols using acaricides to control a multi-resistant strain of Rhipicephalus microplus under field conditions in Southern Brazil

The cattle tick, Rhipicephalus microplus, causes severe economic losses to beef and dairy production in several countries. The control of the cattle tick is based mostly on chemical acaricides. Currently, there are reports of tick populations resistant to all six classes of acaricides available on the market. The aim of this work was to evaluate two protocols for the control of the cattle tick, R. microplus, under field conditions. For that, an acaricide rotational-based approach and selective (partial)-based protocols were tested against a multi-resistant tick strain. Eighteen Brangus cattle were divided into three experimental groups: Group 1, a rotational-based approach aiming at six treatments per year (spring–spring period) using four different classes of acaricide (IPV6 protocol); Group 2, a selective (partial) and rotational-based protocol, in which only half of the animals with the highest tick counts were treated (IPV7S protocol); and Group 3 (non-treated). The protocols were able to maintain low tick infestation during the 57 weeks of study. The two experimental groups showed lower tick counts than the non-treated group, but not between them. Weekly efficacy of the experimental protocols reached 95% in Group 1 and 88% in Group 2. Herein, we proposed two protocols of cattle tick control (IPV6 and IPV7S) for use in multi-resistant tick populations in Southern Brazil.

Wheat nitrogen utilization efficiency and yield as affected by nitrogen management and environmental conditions

Nitrogen (N) is the main nutrient for plant nutrition, however, its fertilization management is still very complex. To evaluate wheat N utilization efficiency (NUtE) and yield in response to N fertilization management considering the influence of environmental conditions, an experiment was carried out in three field conditions in Southern Brazil: Londrina in rainfed and irrigation conditions, and Ponta Grossa in rainfed. A complete (2 × 2 × 2) + 1 factorial arrangement evaluated two N rates (40 and 80 kg ha-1), two N sources (ammonium nitrate and urea), two N timings of fertilization (at sowing or at the beginning of plant tillering), and additional treatment without N fertilization. Agronomic characteristics related to wheat productivity and N plant nutrition were evaluated. Irrigation increased the density of fertile spikes and the N accumulated in the shoot dry matter at anthesis, which partially explained the better grain yield in the irrigated condition. The higher N accumulation in the shoot dry matter was essential for grain yield increase in the environments with lower water deficit, based on their higher NUtE for grain yield. Nitrogen fertilization reduced NUtE for grain yield in Londrina (in rainfed and irrigation conditions), and increased NUtE for shoot dry matter production in all environments. In a colder condition (i.e. Ponta Grossa), the use of a higher N rate at sowing provided greater grain yield, thousand-grain weight, and density of fertile spikes. Nitrogen rate can be reduced in warmer and wetter environmental conditions that favor the mineralization of soil organic matter and the decomposition of soybean straw. The choice for urea or ammonium nitrate can be based on economic criteria in environments with low water deficit and low potential for NH3 volatilization. Nitrogen fertilization carried out exclusively at wheat sowing may be suitable to supply spring wheat N requirements.

Geneva® Series Rootstocks for Apple Trees Under Extreme Replanting Conditions in Southern Brazil.

Geneva® rootstocks in Brazil are known to be efficient in controlling vigor, and are precocious and resistant to diseases. The objective of this study was to evaluate the performance of apple tree cultivars grafted on the Geneva® rootstocks in severe replant disease areas, by planting 60 days after the eradication. The experiments were implemented in 2017, in São Joaquim and Vacaria. The Gala Select and Fuji Suprema cultivars were grafted onto ‘G.202’, ‘G.814’, ‘G.210’, and ‘G.213’ rootstocks in the Tall Spindle training system. In 2018/2019, total thinning was carried out to promote plant growth. In São Joaquim, partial thinning was carried out in 2019/2020 harvest of ‘Gala Select’. The rootstocks were divided into two groups based on vigor, for both areas and cultivars. ‘G.202’ and ‘G.213’ were 40% less vigorous than ‘G.210’ and ‘G.814’. For ‘Gala Select’, the extreme non-fallow condition mainly affected the vigor and productivity of ‘G.213’ in both areas. At the end of two harvests, ‘G.213’ was 17% less productive than ‘G.210’, contrary to what is observed in areas where the fallow period is respected. However, ‘G.213’ confirmed a greater yield efficiency, which was 27% higher than ‘G.210’. This suggests that a perspective of forecasting production for the third crop is higher for ‘G.213’ than for ‘G.210’. In the case of ‘Fuji Suprema’, the G.210 rootstock was the most productive in both areas. In São Joaquim, ‘G.202’ matched ‘G.210’ in productivity and efficiency as it sprouts better in colder regions. Considering the fruit quality, ‘G.213’ anticipated the maturation with fruits of larger size and higher total soluble solids (TSS) in both areas and cultivars, making it possible to anticipate the harvest. It was concluded that the non-fallow condition does not alter the relative differences in vigor and fruit quality among the rootstocks. However, notwithstanding the overall replant tolerance of these rootstocks, it does reduce productivity by mainly affecting less vigorous rootstocks that need about three crops to overcome the allelopathic effects of the soil and start growing normally. The G.210 semi-dwarfing rootstock is an alternative for the immediate conversion of apple orchards of Gala Select and Fuji Suprema cultivars in southern Brazil.

Evaluation of losses and quality maintenance of wheat during storage in a commercial unit in Brazil.

Specific studies of Brazilian wheat storage on a commercial scale on the maintenance of wheat quality are required since the continental extent of Brazil has regions of different weather and because of the diversity of the storage network. This study aimed to evaluate the technological quality (physicochemical and rheological), sanitary quality (insects, fungi and mycotoxins) and dry matter loss of wheat stored in a metal silo in a commercial storage unit. Two dynamic samples, collected during loading and unloading of wheat in silos, and four static samples, collected using a commercial pneumatic grain sampler, were used in this study. Silo temperature was higher than 20 °C during the summer season. The temperature was approximately 15 °C from June to December and provided excellent conditions for grain aeration, which resulted in the maintenance of wheat quality, with no changes in hectoliter weight and rheological properties of wheat (falling number, wet gluten and stability). The effect of Alternaria spp. (~220) and Aspergillus flavus (~7) infection on wheat did not differ statistically during the storage period, although a slight increase in A. flavus infection was noted in February (summer season). The wheat mycotoxins deoxynivalenol, zearalenone, aflatoxins and ochratoxin A were not detected during the studied storage period. Finally, dry matter reduced by approximately 0.4% after the storage period - approximately 0.013% per month. The management practices and climate conditions in southern Brazil provided excellent conditions for grain aeration at ambient air temperature and led to the maintenance of wheat quality during the post-harvest period. © 2021 Society of Chemical Industry.

Juice processing potential of different grape cultivars under conditions in southern Brazil

The objective of this study was to evaluate the juice quality of 11 grape cultivars over three productive cycles, aiming to identify which cultivars are indicated to complement the varietal matrix and allow the extension of the harvest period in the region of Vale do Rio do Peixe - SC. The grapes used to elaborate the juices were: BRS Rúbea (RUB), BRS Cora (COR); BRS Violet (VIO); BRS Carmen (CAR), BRS Magna (MAG), Bordô (BOR), Isabel (ISA), Isabel Precoce (IP), Concord (CON), Concord Clone 30 (C30) and SCS 421 Paulina (SCSP), produced in the EPAGRI experimental station vineyard, in Videira-SC. The physical-chemical variables analyzed showed statistically significant differences for the different cultivars. From the analysis of main components performed, it was possible to observe the noticeable differences between the levels of this factor and the correlations between the parameters. ISA and IP showed lower levels of anthocyanins and color, differing from VIO and MAG. CON and C30 stood out for their high acidity and low soluble solids content. BOR, SCSP and RUB presented juices with intense coloring, high content of bioactive compounds, nevertheless they presented lower levels of soluble solids and a higher acidity, while COR presented slightly higher contents for total soluble solids. The cultivars that brought together the greatest number of favorable characteristics (physical-chemical, sensory and extension of the harvest dates) for the juice elaboration in the studied region, proving favorable to complement the productive matrix composed of ISA and BOR, were VIO, MAG, IP, COR and CAR.

Phyllochron, and root system development of six strawberry cultivars with different photoperiodic flowering responses

Bare-root strawberry plants produced in Patagonia accumulate more reserves in the main crown, which allows their immediate development after transplantation. Due to the dependence on these bare-root plants, Brazilian producers use early cultivars, which start the leaves emission and the flower buds differentiation in advance, since these bare-root plants do not always arrive within the estimated time for planting in southern Brazil. The objective of the work was to investigate whether six strawberry cultivars, produced in a greenhouse, differ in their phyllochron, and root system development. Six cultivars were tested, arranged in a randomized block design, with four replications. Bare-root plants were cultivated in soil in a greenhouse. The phyllochron was evaluated by counting the number of leaves, weekly, from the beginning of leaf emission (from the main crown) until the appearance of the first fruit. The roots were digitized by a scanner and the images analyzed by the WinRHIZO® software. ‘Camarosa’ cultivar was considered the earliest to start fruiting, as it had the lowest phyllochron value (69.93ºC day-1 leaf-1), while the cultivar ‘San Andreas’ was the latest (166.67ºC day-1 leaf-1). ‘Albion’ and ‘Aromas’ presented the highest total root length in relation to the other cultivars. In conclusion, the six strawberry cultivars analyzed in this study, with different photoperiodic classifications regarding flowering, differ in relation to their morphophenological performance. In the growing conditions of southern Brazil, phyllochron study indicates that ‘Camarosa’ cultivar is the earliest and ‘San Andreas’ cultivar is the latest. ‘Albion’ and ‘Aromas’ cultivars are more compact plants, with greater potential for the development of the root system.

Plant growth regulators to increase fruit set and yield of ‘Rocha’ pear trees in Southern Brazil

The aim of this study was to evaluate the effect of different aminoethoxyvinilglycine (AVG), thidiazuron (TDZ) and prohexadione calcium (P-Ca) rates sprayed at different timings on fruit set, yield, and fruit quality of 'Rocha' pear trees in different climatic conditions of Southern Brazil. The study was performed in two commercial orchards located in São Joaquim, SC (2015/2016) and Antônio Prado, RS (2016/2017). Plant material consisted of 'Rocha' pear trees grafted onto Pyrus calleryana and quince rootstock 'BA29' in São Joaquim and Antônio Prado, respectively. Treatments consisted of AVG, TDZ and P-Ca sprayed at different rates and timings. Trunk cross-sectional area increase, fruit set, thinned fruit, fruit per tree, yield, average fruit weight, projected yield, yield efficiency, fruit length, fruit diameter, L/D ratio, seed number, flesh firmness, and soluble solids content were assessed. Fruit set and yield were consistently increased by AVG in all experiments. Fruit set was not affected by P-Ca and was significantly decreased by TDZ. However, yield was positively affected by P-Ca 100 mg L-1 sprayed at full bloom + 7 days after full bloom and TDZ 10 mg L-1 at full bloom. Fruit size was consistently increased by TDZ.

Differences in the reproductive behaviour and larval development of two Canthon rutilans subspecies reinforce their thermal regional segregation

AbstractTwo dung beetle subspecies of Canthon rutilans Castelnau (Coleoptera: Scarabaeidae, Scarabaeinae), C. rutilans rutilans and C. rutilans cyanescens, inhabit different environmental temperature conditions in southern Brazil. We developed a laboratory breeding experiment with 60 pairs of individuals of the two subspecies at five temperature conditions (from 15 to 35 °C) to compare the influence of temperature on the behaviour of adults and the development of larvae. The behavioural patterns of the adults in both subspecies differ according to temperature. The size of food balls was smaller and lighter in C. rutilans cyanescens. Although temperature did not influence the feeding behaviour (measured as the number of food balls made), reproductive behaviour (measured as the number of brood balls made by pair) was significantly lower at 15 °C for both subspecies. Besides that, brood balls from C. rutilans rutilans were bigger and heavier at lower temperatures. The number of offspring and the time of emergence depend on temperature too. However, the weight of the offspring and the longevity of adults depend on the subspecies and temperature treatment. These results demonstrate that the subspecies have different thermal adaptations: C. rutilans rutilans has reproductive behaviour adapted to living under colder and broader conditions than C. rutilans cyanescens.

Host–parasite relationship in Magellanic Penguins (Spheniscus magellanicus) during their long northward journey to the Brazilian coast

The Magellanic Penguin Spheniscus magellanicus is one of the main seabird predators in the western South Atlantic. This species presents an opportunist feeding behaviour and its diet, as well as its parasite fauna, varies geographically depending on available prey and intermediate hosts. Despite thousands of Magellanic Penguins being found dead every year in southern Brazil, little attention has been given to their parasite–host interactions in this area. In this context, the aim of the present study was to assess the relationship between Magellanic Penguin diets and gastrointestinal helminth fauna at different age classes and body conditions in southern Brazil. To this end, the gastrointestinal tracts of 63 Magellanic Penguins found dead in 2013 and 2014 were examined. All individuals were parasitized by at least one species and only one penguin did not contain any food remains. A total of 138,209 helminths comprising eight species were found. Moreover, 12 prey species were recorded, including six fish and six cephalopod taxa. The helminth component community composition of juvenile penguins was similar to that of adults but the structure differed according to penguin age class. Cephalopod and crustacean prey species were significantly more frequent in juveniles compared to adults. Adults preyed mainly upon fishes. It was evident that lean individuals, both juveniles and adults, are more intensely infected in southern Brazil. Therefore, the high abundance of helminth parasites and the consumption of less energy-efficient prey cannot be ruled out as contributory factors to the high mortality of this species, mainly lean juveniles, in this area.

Diagnostic yield of targeted sequential and massive panel approaches for inherited neuropathies.

Diagnostic yield of genetic studies for Charcot-Marie-Tooth disease (CMT) is little known, with a lack of epidemiological data to build better diagnostic strategies outside the United States and Europe. We aimed to evaluate the performance of two molecular diagnostic strategies for patients with CMT, and to characterize epidemiological findings of these conditions in southern Brazil. We performed a single-center cross-sectional study, in which 94 patients (55 families) with CMT suspicion were evaluated. Overall, the diagnostic yield of the combined strategy of Multiplex-ligation-dependent-probe-amplification (MLPA) of PMP22/GJB1/MPZ and GJB1/MPZ/PMP22 Sanger sequencing was 63.6% (28/44) for index cases with demyelinating/intermediate CMT suspicion (21 CMT1A-PMP22, 5 CMTX1-GJB1 and 2 with probably CMT1B-MPZ diagnosis). Five of the 11 index cases (45.4%) with axonal CMT had at least a possible diagnosis with next generation sequencing (NGS) panel of 104 inherited neuropathies-related genes (one each with CMT1A-PMP22, CMT2A-MFN2, CMT2K-GDAP1, CMT2U-MARS, CMT2W-HARS1). Detailed clinical, neurophysiological and molecular data of families are provided. Sequential molecular diagnosis strategies with MLPA plus target Sanger sequencing for demyelinating/intermediate CMT had high diagnostic yield, and almost half of axonal CMT families had at least a possible diagnosis with the comprehensive NGS panel. Most frequent subtypes of CMT in our region are CMT1A-PMP22 and CMTX1-GJB1.