Cadmium-mediated toxicity in plant cells is associated with the DCD/NRP-mediated cell death response.

Cadmium (Cd2+ ) is highly harmful to plant growth. Although Cd2+ induces programmed cell death (PCD) in plant cells, Cd2+ stress in whole plants during later developmental stages and the mechanism underlying Cd2+ -mediated toxicity are poorly understood. Here, we showed that Cd2+ limits plant growth, causes intense redness in leaf vein, leaf yellowing, and chlorosis during the R1 reproductive stage of soybean (Glycine max). These symptoms were associated with Cd2+ -induced PCD, as Cd2+ -stressed soybean leaves displayed decreased number of nuclei, enhanced cell death, DNA damage, and caspase 1 activity compared to unstressed leaves. Accordingly, Cd2+ -induced NRPs, GmNAC81, GmNAC30 and VPE, the DCD/NRP-mediated cell death signalling components, which execute PCD via caspase 1-like VPE activity. Furthermore, overexpression of the positive regulator of this cell death signalling GmNAC81 enhanced sensitivity to Cd2+ stress and intensified the hallmarks of Cd2+ -mediated PCD. GmNAC81 overexpression enhanced Cd2+ -induced H2 O2 production, cell death, DNA damage, and caspase-1-like VPE expression. Conversely, BiP overexpression negatively regulated the NRPs/GmNACs/VPE signalling module, conferred tolerance to Cd2+ stress and reduced Cd2+ -mediated cell death. Collectively, our data indicate that Cd2+ induces PCD in plants via activation of the NRP/GmNAC/VPE regulatory circuit that links developmentally and stress-induced cell death.

Optimized allocation of forest restoration zones to minimize soil losses in watersheds.

Increase of water erosion is one of the main problems in watersheds all over the world and directly affects soil and water resources, causing economic and environmental losses. We proposed a combination of Genetic Algorithm and Erosion/Deposition modelling to allocate vegetation zones in order to reduce soil losses within watersheds. In this study, we have used Unit Stream Power Based Erosion Deposition (USPED) model to predict the spatial distribution of erosion and sediment deposition. Based on USPED estimates, Genetic Algorithm optimize site as well size of forest restoration zones in order to reduce soil losses. Proposed approach considered watershed entirely, in a cell-level optimization, to find the best possible arrangement of forest zones. For initial scenario, soil loss estimate was 2.045,55 ton. ha-1. year-1 and after optimization we achieved 52% reduction. Optimized forest zones formed connected and compacted patches, which enable field implementation. Methodology is also applicable to other watersheds around world.

Geotechnology and landscape ecology applied to the selection of potential forest fragments for seed harvesting.

The Atlantic Forest biome is recognized for its biodiversity and is one of the most threatened biomes on the planet, with forest fragmentation increasing due to uncontrolled land use, land occupation, and population growth. The most serious aspect of the forest fragmentation process is the edge effect and the loss of biodiversity. In this context, the aim of this study was to evaluate the dynamics of forest fragmentation and select potential forest fragments with a higher degree of conservation for seed harvesting in the Itapemirim river basin, Espírito Santo State, Brazil. Image classification techniques, forest landscape ecology, and multi-criteria analysis were used to evaluate the evolution of forest fragmentation to develop the landscape metric indexes, and to select potential forest fragments for seed harvesting for the years 1985 and 2013. According to the results, there was a reduction of 2.55% of the occupancy of the fragments in the basin between the years 1985 and 2013. For the years 1985 and 2013, forest fragment units 2 and 3 were spatialized with a high potential for seed harvesting, representing 6.99% and 16.01% of the total fragments, respectively. The methodology used in this study has the potential to be used to support decisions for the selection of potential fragments for seed harvesting because selecting fragments in different environments by their spatial attributes provides a greater degree of conservation, contributing to the protection and conscious management of the forests. The proposed methodology can be adapted to other areas and different biomes of the world.

Optimizing Mass Rearing of the Egg Parasitoid, Telenomus podisi, for Control of the Brown Stink Bug, Euschistus heros.

The parasitoid Telenomus podisi Ashmead, 1893 is used in biological control programs in Brazil against eggs of Euschistus heros (Fabricius, 1798), a key pest of soybean, Glycine max (L.) Merr. To optimize the mass production of parasitoids, artificial diets and storage of host eggs at low temperatures have been developed; however, direct comparisons of the effects of these conditions have not occurred. We assessed a double factorial arrangement composed of six treatments (fresh or cryopreserved E. heros eggs from adults fed on natural or two artificial diets). We evaluated the biological characteristics and parasitism capacity of T. podisi produced from these treatments across seven temperatures. The thermal range between 21 and 30 °C resulted in satisfactory daily parasitism in all treatments tested, with an inverse relationship between temperature and female survival. The best parasitoid biological parameters were found between 21 and 27 °C, where all tested diets supported T. podisi development, with the best results from artificial diets. Fresh eggs and those frozen in liquid nitrogen and stored at -196 °C until use supported parasitoid development. These results suggest that the best method to mass rear T. podisi is to use artificial diets to rear E. heros and store eggs until needed, and then rear parasitoids at 24 °C.

Trade-Offs between Temperature and Fitness in Euschistus heros (Fabricius) (Hemiptera: Pentatomidae): Implications for Mass Rearing and Field Management.

The brown stink bug, Euschistus heros (Fabricius, 1798) (Hemiptera: Pentatomidae), is one of the most abundant soybean stink bug pests in Brazil. Temperature is a key factor that affects its development and reproduction, and fluctuating temperatures may impact the development and reproduction of E. heros differently from those under constant temperatures. The objective of this study was to evaluate the influence of constant and fluctuating temperature on the biological characteristics of E. heros in three successive generations. Treatments consisted of six constant temperatures (19 °C, 22 °C, 25 °C, 28 °C, 31 °C and 34 °C) and four fluctuating temperatures (25:21 °C, 28:24 °C, 31:27 °C, and 34:30 °C) evaluated for three successive generations. Second-stage nymphs were evaluated daily, and after they reached the adult stage, they were separated by sex, and the individual weight (mg) and pronotum size (mm) were recorded. After pair formation, eggs were collected to evaluate the pre-oviposition period, total number of eggs, and egg viability. The duration of the nymphal stage was reduced with an increase in both constant and fluctuating temperatures; however, at constant temperatures of 19 °C, 31 °C and 34 °C and fluctuating temperatures of 28:24 °C, there was no reproduction in adults. The base temperature and total degree day requirement for nymphal development were 15.5 °C and 197.4 dd, respectively. Pre-oviposition period (d), number of eggs per female, and viability of eggs (%) were affected by temperature across the generations. The multiple decrement life table analysis revealed that mortality was highest during the molting of the second-stage nymphs. These findings have important implications for E. heros' laboratory mass-rearing programs and for its management in fields.

Relation of El Niño and La Niña phenomena to precipitation, evapotranspiration and temperature in the Amazon basin.

Weather phenomena El Niño and La Niña are observed by meteorological variables, which allows you to track climate change and its possible effects in certain regions. The objective of this study was to analyze the behavior of rainfall, temperature and evapotranspiration in the Amazon river basin (Latitudes 5° N to 20° S and Longitudes 50° W to 80° W), comparing them with the occurrence of El Niño and La Niña phenomena, from January 2000 to December 2016. The values referring to the meteorological variables were obtained from the TRMM and MODIS orbital sensors. After data pre-processing, the data were separated into monthly and annual scales and per period according to the presence or absence of El Niño and La Niña phenomena. Based on the results obtained, it was observed that the studied variables were affected by modification of both phenomena. The modifications are more noticeable in the distinction between the more and less rainy periods. Among the variables studied, the evapotranspiration was severely affected in the rainiest months, the La Niña phenomenon, and the least rainy months, El Niño. Thus, it was possible to conclude that, in general, the presence of La Niña increased precipitation values in comparison to the Neutral period, but the inverse occurs in the presence of El Niño. The methodology applied in the present study was adequate for the analysis of the modifications of the meteorological variables coming from the El Niño and La Niña phenomena, being able to be adapted to other variables and regions.

Performance of Trichogramaspp in small tomato borer (Neoleucinodes elegantalisGuenée): Pest management with egg parasitoid

The tomato is a crop of great importance for Brazilian agriculture. Among the most damaging pests, the small tomato borer, Neoleucinodes elegantalis Guenée (Lepidoptera: Crambiadae) has caused great losses, since they directly reach the fruits to be commercialized, being used for its handling a large volume of insecticides. In this way, the use of alternative techniques that help in the management of this pest becomes of great importance. Among them, the use of the egg parasitoid Trichogrammaspp. has been promising. Thus, the present study aimed to evaluate the performance of Trichogrammaspecies and/or strains in N. elegantalisby selection of strains. The selection was made based on four lineages maintained in the Nucleus of Scientific and Technological Development in Phytosanitary Management of Pests (NUDEMAFI), being three strains of the species T. pretiosumand one of T. galloispecies. The parameters evaluated were percentage of parasitized eggs, egg viability, number of individuals per eggs, sex ratio and number of Trichogrammaspp. to be released. The T. galloi(T. g1) showed the best parameters for selection of the strain. Estimating the optimal number of T. g1 in eggs of small-fruit-borerwas 82 individuals per egg parasitoid. Therefore, this strain wasselected for the management of the small tomato-borer, whose eggs presented favorable physicochemical characteristics for the development of the parasitoid.

Selection of parasitoids of the genus Trichogramma (Hymenoptera: Trichogrammatidae) and parasitism at different eggs ages of Duponchelia fovealis (Lepidoptera: Crambidae) / Seleção de parasitoides do gênero Trichogramma (Hymenoptera: Trichogrammatidae) e parasitismo em ovos de diferentes idades de Duponchelia fovealis (Lepidoptera: Crambidae)

The European pepper moth Duponchelia fovealis (Zeller, 1847) (Lepidoptera: Crambidae), despite being among the principal pests of strawberries in Brazil. However, biological control methods are rarely documented for this pest. In the current study, the goal was to select promising Trichogramma strains to enable the control of D. fovealis and to determine the acceptance of different ages of host eggs by the parasitoid. In the first bioassay, evaluations were done on the biological parameters of five strains of Trichogramma pretiosum Riley and one of Trichogramma galloi Zucchi (Hymenoptera: Trichogrammatidae). The best performance came from the strains, Tp18 (T. pretiosum) and Tg (T. galloi), showing parasitism and viability higher than 50 and 90%, respectively. Another bioassay revealed the acceptance of both these species (Tp18 and Tg) for different ages of D. fovealis eggs. All host ages were accepted by T. pretiosum (Tp18) and T. galloi, with a preference for younger eggs (65% parasitism). Adult emergence, number of individuals per egg and sex ratio revealed no significant differences with respect to the host age. The current study provides pertinent data on the selection and performance of Trichogramma species on D. fovealis eggs of different ages.

A traça do morangueiro Duponchelia fovealis (Zeller, 1847) (Lepidoptera: Crambidae) é uma das principais pragas da cultura do morango no Brasil. Entretanto, métodos de controle biológico desta praga são raramente documentados. Este trabalho teve como objetivo selecionar linhagens de Trichogramma e avaliar o parasitismo de diferentes idades de ovos de D. fovealis. Foram avaliados os parâmetros biológicos de cinco linhagens de Trichogramma pretiosum Riley e uma de Trichogramma galloi Zucchi (Hymenoptera: Trichogrammatidae). As espécies/linhagens com melhor desempenho foram Tp18 (T. pretiosum) e Tg (T. galloi), com taxas de parasitismo e viabilidade acima de 50 e 90%, respectivamente. Em seguida, foi avaliada a suscetibilidade das duas espécies (Tp18 e Tg) em diferentes idades de ovos de D. fovealis. Todas as idades do ovo hospedeiro avaliadas foram aceitas pelos dois parasitoides e houve uma maior tendência a parasitar ovos mais jovens. Em todas as idades do hospedeiro houve emergência de parasitoides adultos, e sem diferença significativa entre idades. As variáveis número de indivíduos por ovo e razão sexual não apresentaram diferença significativa quanto à idade do hospedeiro. O atual estudo fornece informações sobre a seleção e o desempenho de espécies de Trichogramma em diferentes idades de ovos de D. fovealis.

Parâmetros biológicos e tabela de vida de Tetranychus urticae (Acari: Tetranychidae) em cultivares de mamão / Biological parameters and life table of Tetranychus urticae (Acari: Tetranychidae) at papaya cultivars

Este trabalho foi realizado para avaliar o desenvolvimento e reprodução de Tetranychus urticae em cultivares comerciais de mamão Carica papaya. Foram utilizadas cultivares do grupo "Formosa" ("Tainung 01" e "Calimosa") e do grupo "Solo" ("Golden" e "Sunrise"). Para iniciar o bioensaio, foi transferida uma fêmea fertilizada por disco de folha (n=50 repetições) e retirado após um período de 12h, sendo avaliada a cada 12h, registrando-se o período de incubação, duração do estágio de imaturo, longevidade e fecundidade dos adultos e viabilidade desses estágios. Os resultados indicaram que as cultivares de mamão "Tainung 01", "Calimosa", "Sunrise" e "Golden" são bons hospedeiros para T. urticae. O parâmetro viabilidade não sofreu influência das cultivares em todas as fases de desenvolvimento avaliadas, apresentando valores superiores a 90%. Não houve diferença estatística entre as cultivares nos parâmetros: período de pre-oviposição e viabilidade dos ovos. A cultivar "Tainung 01" apresentou menor potencial hospedeiro, embora houvesse menor duração nos estágios de ovo, larva, protoninfa e ovo-adulto. Nos parâmetros de tabela de vida e fertilidade, apresentou menores valores de Ro, r m e λ e maior valor de Td. Entre as cultivares, o "Sunrise" apresentou um elevado potencial hospedeiro para T. urticae, pois essa cultivar proporcionou a maior produção de ovos por fêmea, maior longevidade das fêmeas, bem como a maior taxa de reprodução (maior Ro, r m e λ e menor valor de Td).

The study was conducted to evaluate the Tetranichus urticae development and reproduction in commercial Carica papaya cultivars. The assayed cultivars belongs to the "Formosa" ("Tainung 01" and "Calimosa") and from the "Solo" ("Golden" and "Sunrise") groups. A fertilized female was transferred to a leaf dish (n=50 repetitions) and was removed after a period of 12 hours and evaluations were done every 12 hours recording the incubation period, length of immature stage, longevity and fecundity of adults and viability of these stages. The cultivars of papaya, "Tainung 01", "Calimosa", "Sunrise" and "Golden" are adequate hosts for T. urticae. The recorded viability above 90% was not influenced by the different cultivars during all the development phases. There was not statistic difference among the cultivars in the parameters: pre-ovopositional period, and egg viability. Mites assayed in "Tainung 01" cultivar showed a shorter duration of the egg, larva, protonymph and egg-adult. At life table parameters and fertility, presented smaller Ro, r m and λ, and larger Td. "Sunrise" is the cultivar most adequate for T. urticae development, considering that mites assayed in this cultivar showed a larger production of eggs per female, longer female longevity, and higher reproduction rate (larger Ro, r m and λ and smaller Td).