Physiological and biochemical adaptation to salinity in wild halophytes suitable for Mediterranean agriculture

Due to the accelerating processes of soil salinization and shortage of fresh water, the practice of saline agriculture is gaining momentum in many areas of the world. However, there are some concerns that using saline water for irrigation may be non-environmentally sustainable, with potential to cause irreversible soil degradation. In addition, there is a lack of information on the morphological, physiological, and biochemical changes that can occur in plants when irrigated with saline water. In light of the above, the major aim of this work was to investigate the effects of a range of water salinity levels and irrigation regimes on the performances of salt tolerant species promising as future crop plants for saline agriculture. The following objectives were addressed: To determine the effects of different water regimes (leaching irrigation vs. no leaching irrigation) with water at increasing salinity concentrations on the growth, ion accumulation and water relations of Sorghum bicolor plants grown under saline soil conditions. To describe the germination response of Salicornia europaea seeds across a wide range of water salinity levels through six reliable indices for screening salinity tolerance at the seed germination stage. To explore the different physiological responses of six wild halophytes commonly found in the Mediterranean area (Artemisia absinthium, Artemisia vulgaris, Atriplex halimus, Chenopodium album, Salsola komarovii, and Sanguisorba minor), and rank their tolerance after exposure to growing levels of water salinity. To identify the main adaptation mechanisms that distinguish C3 from C4 halophytes when exposed to increasing salinity in the growth media, through a comparative study between the C3 species Atriplex hortensis and the C4 species Atriplex halimus. To identify the main adaptation mechanisms that distinguish annual from perennial halophytes when exposed to severe conditions of salinity and drought, through a comparative analysis between two annual Salicornia spp. and the perennial Sarcocornia fruticosa

Growth, yield and quality attributes of guar (Cyamopsis tetragonoloba L.) genotypes grown under different planting dates in a semi-arid region of Pakistan

Guar (Cyamopsis tetragonoloba L.) is grown in semi-arid regions worldwide as a forage, vegetable, and green manure crop. An experiment was conducted to evaluate growth, forage yield and nutritional quality of guar genotypes grown under different sowing dates. To this end, seven genotypes, viz., Desi Punjab, Farmi Punjab, Desi Sindh, Farmi Sindh, BR-90, BR-2017 and Baluchistan were grown at three sowing times (mid-May, late-May and early-June) during the two years 2020 and 2021. Results showed that maximum leaf area and pods per plant were recorded in genotype Farmi Punjab, while maximum fresh and dry forage yield were archived in genotype ‘BR-90’. Similarly, maximum crude protein in the forage and gum content in mature seeds, were also recorded in BR-90. In addition, mid-May was proved to be the best sowing time for guar genotypes studied in view of achieving maximum morphological traits, fresh and dry forage yield and forage quality, compared to later planting times. Moreover, late sowing caused reduction in yield and other related attributes. It is perceived that synthetic guar variety BR-90 and planting time at mid-May are the best for semi-arid region of Punjab, Pakistan

Mitigation of salt stress in lettuce by a biostimulant that protects the root absorption zone and improves biochemical responses

Horticultural crops constantly face abiotic stress factors such as salinity, which have intensified in recent years due to accelerated climate change, significantly affecting their yields and profitability. Under these conditions, it has become necessary to implement effective and sustainable solutions to guarantee agricultural productivity and food security. The influence of BALOX®, a biostimulant of plant origin, was tested on the responses to salinity of Lactuca sativa L. var. longifolia plants exposed to salt concentrations up to 150 mM NaCl, evaluating different biometric and biochemical properties after 25 days of treatment. Control plants were cultivated under the same conditions but without the biostimulant treatment. An in situ analysis of root characteristics using a non-destructive, real-time method was also performed. The salt stress treatments inhibited plant growth, reduced chlorophyll and carotenoid contents, and increased the concentrations of Na+ and Cl- in roots and leaves while reducing those of Ca2+. BALOX® application had a positive effect because it stimulated plant growth and the level of Ca2+ and photosynthetic pigments. In addition, it reduced the content of Na+ and Cl- in the presence and the absence of salt. The biostimulant also reduced the salt-induced accumulation of stress biomarkers, such as proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2). Therefore, BALOX® appears to significantly reduce osmotic, ionic and oxidative stress levels in salt-treated plants. Furthermore, the analysis of the salt treatments’ and the biostimulant’s direct effects on roots indicated that BALOX®’s primary mechanism of action probably involves improving plant nutrition, even under severe salt stress conditions, by protecting and stimulating the root absorption zone

Formação de professores pela construção coletiva de um projeto de educação ambiental na escola

Embora exista uma legislação que torna a Educação Ambiental obrigatória em todos os níveis de ensino, esta não é desenvolvida na escola como práxis pedagógica o que, segundo alguns professores, se deve às dificuldades por eles encontradas em função do desconhecimento dos objetivos e princípios da Educação Ambiental e de como podem articular os assuntos relativos às questões ambientais aos conteúdos específicos das diferentes disciplinas. Assim, através da pesquisa participante, este estudo objetivou investigar quais são estas dificuldades e responder ao seguinte questionamento: O processo de construção coletiva de um projeto de educação ambiental na escola, poderia ser considerado como uma atividade que contribui para a formação docente? Para isso, foram realizados vários encontros com um grupo de professores do ensino fundamental e médio de uma escola da rede pública estadual do município de Presidente Prudente (SP), durante os quais foram investigadas as concepções de ambiente dos docentes e as dificuldades por eles enfrentadas ao desenvolverem a educação ambiental na escola. Nestes encontros também foi realizado um estudo coletivo, visando ao oferecimento dos subsídios considerados necessários para que os educadores pudessem construir um projeto de educação ambiental para a escola. Foi possível observar que a realização desta atividade, bem como das discussões que ocorreram durante o processo de construção do projeto, contribui para a formação dos professores, uma vez que a dimensão alcançada pelo projeto que construíram foi além das ações pontuais que até então haviam desenvolvido nas ocasiões em que trabalharam com a educação ambiental.Even though there is a legislation making it compulsory to teach Environmental Education courses in all grades of public and private schools, teaching those courses is not a common practice. According to some teachers, the law is not obeyed, in general, because teachers meet some difficulties when preparing such courses. Those difficulties are basically due to not knowing the aims and essence of the Environmental education as well as not knowing how to relate the environmental concerns with the specific topics of the different courses taught in each grade.Hence, this work has its aim to learn about the difficulties faced by the techers and to answer the following question: Could the process of group preparation of an environmental education project in a school be considered as an activity that contributes to teachers education? In order to answer that question, this study uses participatory research. Several meetings were held with a group of teachers from elementary and secondary grades of a public school in the city of Presidente Prudente (SP).During those meetings the perception that teachers had about environment and the difficulties faced by them when developing environmental education courses in the school were analyzed. Also a group study aiming to offer the necessary tools so that teachers cound prepare an environmental education project in the school was formed. It was possible to observe that task as well as the group discussions that occurred during the preparation of the project aided in the teachers education. That can be corroborated when observing that the aims proposed in the project prepared by them reached far beyond the actions developed in previous situations where environmental education had been addressed. Furthermore, there was a change in the idea that those teachers had about environmental education.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Assessing Salicornia europaea Tolerance to Salinity at Seed Germination Stage

Salicornia europaea, a halophytic species, was investigated to assess its ability to withstand salinity during seed germination, and to identify suitable indices to interpret salt tolerance at this delicate stage. Seed germination indices (germination percentage (GP), germination energy (GE), germination value (GV), coefficient of germination velocity (CVG), germination rate index (GRI), germination peak value (GPV), mean germination time (MGT), and time to 50% germination (T50)) were calculated under increasing salinity (0, 100, 200, 300, 400, and 600 mM NaCl). Principal component analysis (PCA) was used to describe the relationships involving the variables that account for data variance. Two salinity thresholds were identified (100 and 600 mM NaCl) determining significant decreases in all the indices, except for T50 and MGT. In fact, PCA based on generated correlation circle showed significant negative correlations (r close to −1) between salt stress and GP, GE, GRI, PV, GV, and CVG, whereas no correlation was observed with T50 and MGT (r close to zero). Based on this, GP, GE, GRI, PV, GV, and CVG can be considered useful traits to assess salt tolerance during germination in S. europaea, while T50 and MGT, that were not affected by the range of salinity levels investigated, should not be used for this purpose

Data on seed germination using LED versus fluorescent light under growth chamber conditions

The present investigation attempted to assess the influence of two light sources, LED versus fluorescent light, on seed germination of nine aromatic species belonging to the genus Artemisia, Atriplex, Chenopodium, Salicornia, Sanguisorba, Portulaca and Rosmarinus. Pre-germination test was carried out in petri dishes, evidencing the need to overcome seed dormancy through cold stratification in Salicornia europaea. Thereafter, seeds were germinated in small trays with peat moss substrate in two growth chambers illuminated with either LED or fluorescent light featuring similar photosynthetic photon flux density. Germination lasted 20 days, during which time five indexes of germination performance (germination percentage, speed of germination, germination energy, germination rate index, and mean daily germination) were evaluated. At the end, shoot length and seedling fresh weight were assessed as early growth traits. Data are made available to allow critical evaluation of experimental outcome

Effects of soil and water salinity in a sorghum pot experiment

Salinity is associated with reduced water availability because of the drop in soil water potential. Under salt stress, sorghum can lower leaf water potential to maintain water uptake and cell hydration, resulting in osmotic adjustment (Yang et al., 1990; Weimberg et al., 1984). The objective of this investigation was to determine the effects on sorghum growth and leaf water status at varying levels of soil and water salinit

Data on seed germination using LED versus fluorescent light under growth chamber conditions

The present investigation attempted to assess the influence o ftwo light sources, LED versus fluorescent light, on seed germination of nine aromatic species belonging to the genus Artemisia, Atriplex, Chenopodium, Salicornia, Sanguisorba, Portulaca and Rosmarinus. Pre-germination test was carried out in petri dishes, evidencing the need to overcome seed dormancy through cold stratification in Salicornia europaea. Thereafter, seeds were germinated in small trays with peat moss substrate in two growth chambers illuminated with eithe rLED or fluorescent light featuring similar photosynthetic photon flux density. Germination lasted 20 days, during which time five indexes of germination performance (germination percentage, speed of germination, germinatio nenergy, germination rate index, and mean daily germination) were evaluated. At the end, shoo tlength and seedling fresh weight were assessed as early growth traits. Data are made available to allow critical evaluation of experimental outcome

Valutazione ex post del recupero e riuso ai fini irrigui di acque reflue della depurazione civile alla scala reale

During the first four years\u2019 operation of the first Emilia-Romagna tertiary treatment plant of urban wastewater (Mancasale, Reggio Emilia), the volumes of recovered wastewater increased from 3.5 million in 2016 up to almost 6 million cubic meters in 2018 and 2019. The average hourly flow rates fluctuated between 1,200-1,400 m3/hour. The results of the chemical-physical and biological analysis confirmed the correct plan functioning, although the levels of sodium, ammoniacal nitrogen and mineral oils showed a greater degree of risk. The farmers were generally satisfied with the actual management of the irrigation service including the recovery of the treated wastewater. Almost all of them did not observe changes in the availability and quality of the irrigation water and perceived advantages rather than risks linked to wastewater recovery for irrigation, proving to be favourable to the spread of this good practic