RESUMO O espargo do mar (Salicornia neei Lag.) é um vegetal gourmet que vem sendo estudado experimentalmente devido à sua alta qualidade nutricional. A rega salina pode influenciar vários aspectos químicos da planta. Portanto, o objetivo deste estudo é investigar a composição mineral de progénies de S. neei submetidas ao cultivo com dois regimes de rega salina de efluente de criação de camarão marinho. O cultivo foi realizado com quatro progénies (dois biótipos: BTH1 e BTH2; duas gerações: F3 e F4) de S. neei em canteiros, cada canteiro correspondeu a um regime de rega (T2: a cada dois dias; T4: a cada quatro dias). Os resultados deste estudo sugerem que a rega influenciou a composição mineral das plantas. Poucas características nutricionais (e.g. N, Ca, Cu e Mn) das progénies de S. neei foram afetadas pelo experimento de rega, demonstrando o alto grau de adaptação desta espécie ao estresse hídrico/salino. O regime de rega mais prolongado (i.e. T4) foi o mais adequado para a produção de plantas, pois estas apresentaram um maior teor de N e menores teores de Cu e Mn do que T2. Para diferenças entre progénies, a linhagem BTH2 apresentou maior acumulação de P e Mg, o que a torna uma opção como vegetal gourmet na agricultura salina.

ABSTRACT Sea asparagus (Salicornia neei Lag.) is a gourmet vegetable that has been experimentally studied due to its high nutritional quality. Saline irrigation may influence several chemical aspects of the plant. Therefore, the objective of this study is to investigate the mineral composition of S. neei progenies subjected to cultivation with two saline irrigation schedules from marine shrimp farming effluent. The cultivation was carried out with four progenies (two biotypes: BTH1 and BTH2; two generations: F3 and F4) of S. neei in field plots, each plot corresponded to an irrigation regime (T2: every two days; T4: every four days). The results of this study suggest that irrigation influenced plants’ mineral composition. Few nutritional characteristics (e.g. N, Ca, Cu and Mn) of S. neei progenies were affected by the irrigation experiment, demonstrating the high degree of adaptation of this species to water/saline stress. The more prolonged regime of irrigation (i.e. T4) was the most suitable for plant production, as the plants presented a higher N content and lower Cu and Mn content than T2. For differences between progenies, the BTH2 lineage showed greater accumulation of P and Mg, which makes it an option as a gourmet vegetable in saline agriculture.

Abstract Biofloc technology (BFT) systems are sustainable for aquaculture due to the growth of microorganisms in the culture medium that can uptake toxic nitrogen compounds, which generates “in situ” microbial protein that can be eaten, decreasing feed costs. BFT brown (formed with no direct natural light and bacterial dominance) and green (exposed to direct natural light, algal system) waters can be potentially used for aquaponics of commercial halophytes. This study evaluated changes in physical-chemical parameters and macronutrient concentrations of brown and green saline waters of BFT systems, with marine shrimp (Litopenaeus vannamei) breeding stock, subjected to a one-week recirculation cycle in saline aquaponics with halophytes (Salicornia neei, Apium graveolens and Paspalum vaginatum). For 30 days in the summer of 2019, clarified brown and green waters of BFT systems of L. vannamei were used for aquaponic cultivation of these three halophytes. Water samples were collected before and after one week of water recirculation in the aquaponic systems. Halophytes grow well with both water types. The brown water had a higher phosphate concentration and its nitrate content reduced 3-fold in magnitude after one week of recirculation. The green water had higher average concentrations of nitrate, potassium, calcium, magnesium and sulfate compared to the brown water, and its nitrate and nitrite contents significantly increased after one week of recirculation. The remediation of dissolved macronutrients using aquaponics can be ineffective for green water types, mainly due to the death and decay of photoautotrophic microorganisms during the water recirculation process inside aquaponic structures.

Abstract: Aim This study focused on the spatiotemporal variation of the benthic diatom community structure in salt marshes from the Patos Lagoon estuary and their relationship with environmental variables. Methods Samplings were carried out in the winter of 2010 and summer of 2011 (during El Niño and La Niña) in sites with different sediment granulometry, salinity, and distances from the Atlantic Ocean. The surface sediment was collected using a core (10 cm in diameter and 2 cm in depth) and the benthic diatoms were removed following the Trapping method, allowing the observation of live diatoms. Results The richness values (18 and 48 taxa), evenness (0.41 and 0.68), and Shannon diversity indices (2.02 and 3.31 bits/ind.) variations were not significative between the sites and seasons, although temperature and salinity differed significatively between winter and summer. However, the diatom's composition and distribution were related to temperature, salinity, and sediment particle size. Mainly the species Hippodonta hungarica, Luticola simplex Navicula cf. cryptotenelloides, N. erifuga, N. jacobii, Nitzschia filiformis var. conferta, Planothidium frequentissimum and Tryblionella calida were associated with lower temperature and lower salinity in the winter. The species Navicula cf. cryptocephala, N. phylleptosomaformis, Nitzschia pusilla, N. frustulum, N. scalpelliformis and Pseudostaurosiropsis geocollegarum were associated with higher temperature and higher salinity in the summer. Birraphid diatom taxa, mainly species of the genus Navicula and Nitzschia, were frequent or abundant in sandy sediments, and monoraphids, such as Planothidium frequentissimum, were frequent in sites where silt and clay predominated. Conclusions The composition of the benthic diatoms revealed variation between the sites in the winter and summer seasons, during El Niño and La Niña episodes. In winter, high rainfall and freshwater runoff maintained oligohaline condition in the marshes, while in summer, flooding with meso-poly-euhaline waters changed the diatom composition. The granulometry was an important factor in explaining the distribution of the birraphid and monorhapid taxa.

Resumo: Objetivo Este estudo focalizou a variação espaço-temporal da estrutura da comunidade de diatomáceas bentônicas, em marisma do estuário da Laguna dos Patos e sua relação com variáveis ambientais. Métodos Amostragens foram realizadas no inverno de 2010 e verão de 2011(durande o El Niño e La Niña) em locais com diferentes granulometrias do sedimento, salinidades e distâncias do Oceano Atlântico. O sedimento superficial foi coletado utilizando um core (10 cm de diâmetro e 2 cm de profundidade) e as diatomáceas bentônicas foram removidas, seguinto o método Trapping, que permite a observação das diatomáceas vivas. Resultados As variações dos valores de riqueza (18 e 48 taxa), uniformidade (0.41 and 0.68) e índice de diversidade de Shannon (2.02 and 3.31 bits/ind.) entre os locais e estações não foram significativos, embora a temperatura e salinidade diferiram, significativamente, entre o inverno e verão. Entretanto, a composição e distribuição das diatomáceas estiveram relacionadas à temperatura, salinidade e tamanho de partícula do sedimento. Principalmente as espécies Hippodonta hungarica, Luticola simplex Navicula cf. cryptotenelloides, N. erifuga, N. jacobii, Nitzschia filiformis var. conferta, Planothidium frequentissimum and Tryblionella cálida, estiveram associadas às mais baixas temperatura e salinidade no inverno. As espécies Navicula cf. cryptocephala, N. phylleptosomaformis, Nitzschia pusilla, N. frustulum, N. scalpelliformis and Pseudostaurosiropsis geocollegarum estiveram relacionadas as mais altas temperatura e salinidade no verão. Diatomáceas birrafídeas, principalmente espécies do gênero Navicula e Nitzschia foram frequentes ou abundantes em sedimentos arenosos e, monorrafídeas, tais como Planothidium frequentissimum foram frequentes em locais, onde predominaram silte e argila. Conclusões A composição das diatomáceas bentônicas revelou variação entre os locais nas estações de inverno e verão, durante os episódios de El Niño and La Niña. No inverno, alta pluviosidade e alto escoamento de água doce manteve condição oligohalina nas marismas, enquanto que, no verão, a inundação de água meso-poly-euhalina mudou a composição das diatomáceas. A granulometria foi um fator importante para explicar a distribuição dos táxons birrafídeos e monorrafídeos.

ABSTRACT Seeds of wild celery (Apium graveolens L.) from southern Brazil were surface disinfected with different solutions of sodium hypochlorite (5 and 10%) and acetic acid (0.5, 1, 2, 4%), and germination success and fungal infection were evaluated after 28 days of incubation at a constant temperature of 30 ºC and 20/30 ºC thermoperiod (12h:12h). Germination of wild celery was inhibited at the constant temperature (30 ºC). Vigorous total germination (90-100%), a faster germination velocity (1.8-2.5 germinated seeds per day) and moderate fungal infection (53.3-81.7%) of wild celery seeds were obtained with the sodium hypochlorite treatments (5-10% concentration) under the 20/30 ºC thermoperiod. The 4% treatment of acetic acid was very effective at preventing seed fungal infection (only 5% of the seeds) but it reduced the average total germination to 60%. Lower concentrations of acetic acid (0.5-2%) resulted in 100% fungal infection. In conclusion, seedlings of wild celery from southern Brazil can be effectively produced by disinfecting the seeds with 5 -10% sodium hypochlorite and incubation under a 20/30 ºC thermoperiod (12h:12h).

RESUMO As gramas halófitas Spartina alterniflora e Spartina densiflora são espécies bioengenheiras, que podem ser utilizadas para mitigação de áreas degradadas de marismas e manguezais, para o controle da erosão costeira e para estabilização de dragado depositado em regiões estuarinas e costeiras. O objetivo deste trabalho foi avaliar os efeitos da densidade de plantio e da adubação com nitrogênio (N) e fósforo (P) sobre mudas de propagação vegetativa destas duas espécies, crescendo em bandejas (0,15 m2; 7500 cm3). Para isto, foram realizados em estufa agrícola, não climatizada, dois experimentos nos anos de 2009 e 2011. Em 2009, apenas S. alterniflora foi cultivada, em duas densidades de plantios (133 e 400 mudas m-2) e com dois níveis de adição de nutrientes (sem adubação e com adição total de 50,8 gN m-2 e 16 gP m-2). Em 2011, bandejas com 80 mudas m-2 de ambas as espécies foram adubadas com razões 2N:1P, 6N:1P, 10N:1P e 14N:1P (adição total de 115 gN m-2). A adubação com NP estimulou a formação foliar e, em recipientes fertilizados, o número médio de hastes de S. alterniflora, após 80 dias, foi o dobro do observado nos recipientes-controle. Entretanto, densidades iniciais de 400 ou mais hastes m-2 nas bandejas resultaram em alongamento vertical excessivo das hastes de S. alterniflora (cerca de 100 cm de altura), o que prejudica o manuseio e o plantio. A adubação com razão 2N:1P resultou em melhor perfilhamento de ambas as espécies.

ABSTRACT The halophytic grasses Spartina alterniflora and Spartina densiflora are bioengineer species, which can be utilized on the mitigation of disturbed areas of salt marshes and mangroves, for coastal erosion control and to stabilize dredged material disposed in estuarine and coastal areas. The effects of planting density and fertilization with nitrogen (N) and phosphorus (P) on container-grown (0.15 m2; 7500 cm3) vegetative propagules of both species were evaluated under greenhouse conditions, through two experiments during the years 2009 and 2011. In 2009, only S. alterniflora was cultivated within 2 planting densities (133 and 400 propagules m-2) and 2 levels of fertilization (without addition and with total addition of 50.8 gN m-2 and 16 gP m-2). In 2011, containers with 80 propagules m-2 of both species received N and P fertilization rates of 2N:1P, 6N:1P, 10N:1P and 14N:1P (for a total addition of 115 gN m-2). NP fertilization stimulated leaf formation and, in fertilized containers, the average number of S. alterniflora tillers was twice larger than control treatments. However, initial planting densities of 400 or more propagules m-2 resulted in excessive vertical growth of S. alterniflora tillers (about 100 cm height), which can result into plant losses during handling and transplantation. For both species, the 2N:1P fertilization rate resulted in higher tillering.

Grazing scars of burrowing crabs and Hemiptera insects were simulated on leaves of the salt marsh grass Spartina alterniflora. Simulations of crab feeding generated two-fold higher fungal (ergosterol) content in leaves in comparison to that generated by insect scar simulations (1.26 ±0.55 and 0.57 ±0.25 µg per cm², respectively). This study provided evidence that herbivory could facilitate microbial infection by fungi in dominant South American salt marsh plants and indicated that specific feeding mechanisms used by different herbivores might differentially impact the strength of this interaction.