Physiological and metabolic alterations in basil (Ocimum basilicum L) varieties under distinct soil water levels / Alteraciones fisiológicas y metabólicas en variedades de albahaca (Ocimum basilicum L) bajo distintos niveles de agua del suelo

Basil (Ocimum basilicumL.) is a medicinal species used in several areas, such as food, medicines and cosmetics, and the understanding of its physiological behavior under environmental conditions is of paramount importance for the improvement of cultivation methods. The objective of this study was to evaluate the influence of different water availability under physiological, biochemical and metabolic characteristics, in three distinct genotypes: 'Alfavaca basilicão', 'Gennaro de menta' and 'Grecco à palla', during two different phenological stages (vegetative and reproductive). It was found that the water deficit promotes physiological changes to tolerate water stress, and the studied genotypes have different routes to achieve this physiological tolerance, which culminates in a distinct accumulation of metabolites in plants, and can be considered interesting if the final product is the production of essential oils.

La albahaca (Ocimum basilicum L.) es una planta medicinal utilizada en varias áreas: alimenticia, medicinal e industria cosmética; es de suma importancia el entendimiento de su comportamiento fisiológico bajo diferentes condiciones ambientales con el fin de mejorar los procesos del cultivo. El objetivo de este estudio fue evaluar la influencia de diferentes disponibilidades hídricas en las características fisiológicas, bioquímicas y metabólicas en tres genotipos de albahaca: "Alfavaca basilicão", "Gennaro de menta" y "Grecco à palla" durante dos etapas fenológicas (vegetativa y reproductiva). Fue encontrado que el déficit hídrico promueve cambios fisiológicos con el fin de tolerar el estrés hídrico. Los genotipos estudiados presentaron diferentes rutas para alcanzar esta tolerancia fisiológica, la cual culmina con distintas acumulaciones de metabolitos en las plantas, y puede ser considerado interesante si el producto final es la producción de aceites esenciales.

Exogenous application of salicylic acid to control coffee rust

The exogenous application of salicylic acid can induce plant resistance against pathogens. However, little is known about the potential uses of this bioregulator for controlling coffee diseases. In this study, we assessed the effect of applying salicylic acid (SA – 150 mg L-1) on the management of coffee rust (Hemileia vastatrix) in a 7-year-old coffee plantation with low crop load (651.6 kg ha-1 in 2017). For comparison, plants were sprayed with protectant fungicide (copper hydroxide – CH) and standard fungicides (SF) used by local farmers (boscalid, pyraclostrobin + epoxiconazole, and copper hydroxide). Non-treated plants were included as a negative control. Five monthly applications were performed from November 2016 to March 2017. Rust incidence and severity, defoliation, and growth of plagiotropic branches were evaluated monthly. The activity of catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and total proteins was assessed one day after the first, third, and fifth product applications. Compared to untreated plants, SA reduced the severity and incidence of rust from 36.3 to 54.7%, while CH and SF reduced disease from 31.8 to 54.6% and from 83.8 to 88%, respectively. SA reduced defoliation by 54.1%. SA increased the concentration of CAT, APX, and SOD after the first application. However, this effect was not observed after subsequent applications. Foliar application of SA reduces the severity and incidence of coffee rust and defoliation in plants with a low crop load.

Attenuation of salt stress by lycopene on common bean seeds / Attenuation of salt stress by lycopene on common bean seeds

Salinity is a major abiotic stress that adversely affects several physiological and biochemical aspects of plants. Antioxidants can be used as a potential remediation mechanism to promote plant resilience. Therefore, the objective of the present study was to evaluate increasing doses of the antioxidant lycopene on the germination and initial growth of common bean seedlings under conditions of salt stress. Seeds were treated with the following lycopene concentrations: 0.018; 0.036; 0.072; 0.144; and 0.288 g L-1 and two controls (negative and positive) and evaluated under two growth conditions (without and with salt stress) for physiological quality and pigment content. Data were analyzed by completely randomized design, in 2 x 7 factorial (two growth conditions, with paper towel moistened with water or salt solution x seven treatments, including five lycopene doses and two controls), in four replicates of 50 seeds by concentration. With the results of the analysis of variance, growth conditions (without and with salt stress) were compared by the Tukey test (5%), and the effects of lycopene doses were analyzed by polynomial regression. Lycopene promoted tolerance of bean seeds to salt stress and had a positive influence on the attenuation of salt harmful effects to the initial growth of seedlings, mainly at the doses of 0.072 g L-1 and 0.144 g L-1.

Salinity is a major abiotic stress that adversely affects several physiological and biochemical aspects of plants. Antioxidants can be used as a potential remediation mechanism to promote plant resilience. Therefore, the objective of the present study was to evaluate increasing doses of the antioxidant lycopene on the germination and initial growth of common bean seedlings under conditions of salt stress. Seeds were treated with the following lycopene concentrations: 0.018; 0.036; 0.072; 0.144; and 0.288 g L-1 and two controls (negative and positive) and evaluated under two growth conditions (without and with salt stress) for physiological quality and pigment content. Data were analyzed by completely randomized design, in 2 x 7 factorial (two growth conditions, with paper towel moistened with water or salt solution x seven treatments, including five lycopene doses and two controls), in four replicates of 50 seeds by concentration. With the results of the analysis of variance, growth conditions (without and with salt stress) were compared by the Tukey test (5%), and the effects of lycopene doses were analyzed by polynomial regression. Lycopene promoted tolerance of bean seeds to salt stress and had a positive influence on the attenuation of salt harmful effects to the initial growth of seedlings, mainly at the doses of 0.072 g L-1 and 0.144 g L-1.

Effect of Thymol on Soybean Seeds Germination: Physiological and Biochemical Analysis

Abstract Higher levels of reactive species of oxygen are harmful to plant tissues. This study evaluated the action of different doses of thymol on soybean seed germination, biometric analysis and enzymatic parameters; both involved in germination process. High doses of thymol affected the plantlet growth, but not hampered the germination.

Aplicação de reguladores vegetais em uva apirena 'Centennial Seedless' / Growth regulators applied on seedless grape 'Centennial Seedless'

O trabalho objetivou avaliar o efeito de doses crescentes do forchlorfenuron associado ou não ao ácido giberélico sobre componentes físico-químicos da uva 'Centennial Seedless' para consumo in natura. Os tratamentos testados foram ácido giberélico (AG3) (0 e 5mg L-1) associado ao forchlorfenuron (0, 2, 4, 6, 8 e 10mg L-1). As variáveis analisadas foram a massa, o comprimento e a largura dos cachos, das bagas e dos engaços, o teor de sólidos solúveis, o pH, a acidez titulável e a relação sólidos solúveis/acidez titulável (SS/AT). O experimento foi conduzido em vinhedo localizado no município de São Miguel Arcanjo, no sudoeste do Estado de São Paulo, sendo os reguladores vegetais aplicados aos 15 dias após o pleno florescimento, mediante pulverização direcionada ao cacho. A interação entre a dose estimada de 5mg L-1 de forchlorfenuron associada ao AG3 proporcionou os maiores ganhos na massa e na largura das bagas, e as doses estimadas de 4 e 6,5mg L-1 de forchlorfenuron, associadas ao AG3, proporcionaram os menores teores de sólidos solúveis e a relação SS/AT, respectivamente. O tratamento com o uso de AG3 resultou em ganhos no diâmetro dos pedicelos e na massa dos cachos, das bagas e dos engaços, além de incrementar o comprimento e a largura das bagas.

The objective of present research was to evaluate the effects of increasing doses of forchlorfenuron associated, or not, to gibberellic acid on physical and chemical components of the ´Centennial Seedless' grapes. The treatments were gibberellic acid (GA3) (0 and 5mg L-1) associated with forchlorfenuron (0, 2, 4, 6, 8 and 10mg L-1). The variables were mass, width and length of bunches, berries and rachis, total soluble solids, pH, acidity and total ratio soluble solids/titratable acidity (SS/TA). The experiment was conducted in a vineyard located in the municipality of São Miguel Arcanjo, southwest of São Paulo State, and the regulators were applied at 15 days after full bloom by spraying the bunch. The interaction of the estimated dose of 5mg L-1 forchlorfenuron associated with GA3, provided increases on the mass and width of the berries, and the estimated doses of 4 and 6.5mg L-1 of forchlorfenuron associated with GA3, showed the lowest soluble solids and ratio SS/TA, respectively. The treatment with GA3 resulted in gains in the diameter of the pedicels, mass of bunches, berries and rachis, and increasing the length and width of berries.