Mucuna pruriens cannot develop phytoremediation of tebuthiuron in agricultural soil with vinasse: a morphometrical and ecotoxicological analysis.

Pesticides offer stakeholders cost-effective solutions to control weeds. Nevertheless, such active compounds can manifest as severe environmental pollutants when escaping from agroecosystems into surrounding natural ecosystems, driving the need to remediate them. We, hence, analyzed whether Mucuna pruriens can develop a potential phytoremediator for treating tebuthiuron (TBT) in soil with vinasse. We exposed M. pruriens to microenvironments containing tebuthiuron at 0.5, 1, 1.5, and 2 (standard dose) L ha-1 and vinasse at 75, 150 (industrial recommendation), and 300 m3·ha-1. Experimental units without organic compounds represented controls. We assessed M. pruriens for morphometrical features, such as plant height and stem diameter and shoot/root dry mass, over approximately 60 days. We obtained evidence for M. pruriens not effectively removing tebuthiuron from the terrestrial medium. Such a pesticide developed phytotoxicity, significantly limiting its germination and growth. The higher the dose, the more negatively the tebuthiuron impacted the plant. In addition, introducing vinasse into the system, irrespective of volume, intensified the damage to photosynthetic and non-photosynthetic structures. Equally important, its antagonist action further decreased the production and accumulation of biomass. As M. pruriens could not effectively extract tebuthiuron from the soil, it could allow neither Crotalaria juncea nor Lactuca sativa to grow on synthetic media containing residual pesticide. An atypical performance of such testing (tebuthiuron-sensitive) organisms over independent ecotoxicological bioassays validated inefficient phytoremediation. Hence, M. pruriens could not offer a functional remediative option to treat environmental pollution by tebuthiuron in agroecosystems where vinasse occurs, such as sugarcane-producing areas. Although M. pruriens considered a tebuthiuron phytoremediator as cited in the literature, satisfactory results did not occur in our research due to high concentrations of vinasse in the soil. Therefore, this information requires more specific studies about the influence of high concentrations of organic matter on M. pruriens productivity and phytoremediation performance.

Response of soybean to soil waterlogging associated with iron excess in the reproductive stage.

Soil waterlogging is a common problem in some agricultural areas, including regions under soybean (Glycine max) cultivation. In waterlogged soils, soil O2 depletion occurs due to aerobic microorganisms and plants, affecting the metabolic and physiological processes of plants after suffering anoxia in their root tissue. Another harmful factor in this situation is the exponential increase in the availability of iron (Fe) in the soil, which may result in absorption of excess Fe. The present study sought to evaluate the response mechanisms in soybean leaves 'Agroeste 3680' by physiological and biochemical analyses associating them with the development of pods in non-waterlogged and waterlogged soil, combined with one moderate and two toxic levels of Fe. Gas exchange was strongly affected by soil waterlogging. Excess Fe without soil waterlogging reduced photosynthetic pigments, and potentiated this reduction when associated with soil waterlogging. Starch and ureide accumulation in the first newly expanded trifoliate leaves proved to be response mechanisms induced by soil waterlogging and excess Fe, since plants cultivated under soil non-waterlogged soil at 25 mg dm-3 Fe showed lower contents when compared to stressed plants. Thus, starch and ureide accumulation could be considered efficient biomarkers of phytotoxicity caused by soil waterlogging and excess Fe in soybean plants. The reproductive development was abruptly interrupted by the imposition of stresses, leading to a loss of pod dry biomass, which was largely due to the substantial decrease in the net photosynthetic rate, as expressed by area (A), the blockage of carbohydrate transport to sink tissues and an increase of malondialdehyde (MDA). The negative effect on reproductive development was more pronounced under waterlogged soil.

Green Manure Species for Phytoremediation of Soil With Tebuthiuron and Vinasse.

Tebuthiuron is often used to control weed growth in sugarcane cultures. This herbicide is highly toxic and can persist in soil for up to 2 years according to its degradation half-life. Hence, its residual effect is highly hazardous for the environment and local habitants via leaching, surface runoff. Screening out of species of green manure as potential phytoremediators for tebuthiuron in soil, with and with no vinasse, accordingly is the scientific point of this study. Green manure species selected for the trial in greenhouse were jack bean [Canavalia ensiformis (L.) DC.], pigeon pea [Cajanus cajan (L. Millsp.)], velvet bean [Mucuna pruriens (L.) DC.)], and millet [Pennisetum glaucum (L.) R.Br.], and Crotalaria juncea L. as bioindicator of this herbicide. The determination/quantification of height, stem diameter, and number of leaves in all plants were monitored, as well as other morphological traits for drafting any inference on biomass production. Moreover, ecotoxicity bioassays were performed from soil samples at the beginning and at the end of the experiment. Results showed preliminary evidence of effective phytoremediation capacity by M. pruriens and P. glaucum in soils with tebuthiuron, as the growth of C. juncea was sustained. Both Gompertz approach and principal component analysis predicted that these green manure species could grow healthier and for longer periods in soils containing tebuthiuron and vinasse and, thus, reduce physiological anomalies due to ecotoxicity. The implications of this study may aid in the implementation of cost-effective strategies targeting decontamination of tebuthiuron in sugarcane crops with vinasse application in fertigation.

Mycochemical Characterization of Agaricus subrufescens considering Their Morphological and Physiological Stage of Maturity on the Traceability Process.

Agaricus subrufescens Peck is a basidiomycete with immunomodulatory compounds and antitumor activities. This research evaluated the mycochemical composition of A. subrufescens, considering their morphological and physiological stage of maturity, with a particular focus on the development of a traceability process for the formulation of new nutritional products based on fungal foods. The stipes contained a high amount of dry matter (10.33%), total carbohydrate (69.56%), available carbohydrate (63.89%), and energy value (363.97 kcal 100 g-1 DM). The pilei contained a high amount of moisture (90.66%), nitrogen (7.75%), protein (33.96%), ash (8.24), crude fat (2.44%), acid detergent fiber (16.75 g kg-1), neutral detergent fiber (41.82 g kg-1), hemicellulose (25.07 g kg-1), and lignin (9.77 g kg-1). Stipes with mature physiological stage had higher values of dry matter (10.50%), crude fiber (5.94%), total carbohydrate (72.82%), AC (66.88%), and energy value (364.91 kcal 100 g-1 DM). Pilei of the mushrooms in the immature physiological stage had higher values of P (36.83%), N (8.41%), and A (8.44%). Due to the differences between the mycochemical compositions of the morphological parts of mushrooms linked to their physiological stage of maturity, such characteristics have immense potential to be considered for a traceability process. This study can be used for the purpose of providing the consumer with more product diversity, optimizing bioactivities of composts, and allowing farmers an efficient and profitable use of the mushroom biomass.

Método para mapeamento de locos controladores de características oligogênicas / Genetic mapping of oligogenic traits using maximum likehood functions

Características oligogênicas de distribuição discreta e expressão governada por poucos genes de maior efeito têm se mostrado importantes na condução dos programas de melhoramento, com destaque para a resposta de resistência das plantas às doenças. Métodos tradicionais de detecção de QTL's, que pressupõem normalidade e herança governada por múltiplos fatores, não deveriam ser utilizados para mapeamento dessas características de distribuição discreta e interação epistática predominante. O objetivo deste trabalho é avaliar os resultados de um método para mapeamento e detecção de locos controladores da expressão de características oligogênicas, OTL's (Oligogenic Trait Loci). Esse método, definido como MMCO (Método de Mapeamento de Características Oligogênicas), utiliza funções de verossimilhança para obtenção de estimativas de ligação fatorial entre locos marcadores e locos controladores de características oligogênicas. Os resultados indicam que o método foi adequado para detecção de OTL's em populações F2 relativamente pequenas, compostas por 200 indivíduos, e que a determinação a priori do padrão de herança é condição necessária para a utilização dessa estratégia, que se diferencia por atender as pressuposições de análise, não necessitar de informação prévia de ordenamento entre as marcas e por permitir a obtenção de estimativas a partir da informação contida em todas as classes genotípicas.

Oligogenic traits are distinguished by their heritage ruled by higher effect genes and by their importance for cultivated plants, with emphasis to the plant disease resistance inheritance. The qualitative nature and epistatic interaction of these traits results in a heritage pattern that should not be interpreted through traditional QTL detection strategies. The objective of this work was to propose a method for Oligogenic Traits Loci (OTL) detection. This method, defined as Oligogenic Trait Mapping Method (OTMM) uses maximum likehood probability functions to obtain adjusted "r" estimates that express the distance among the molecular markers and the OTL loci. The results show that the method was adequate for OTL detection even in relatively small F2 populations. The prior definition of the oligogenic heritage pattern is one the main requirements of this method that focus in the attainment of the analysis presumptions without previous markers order information.