ABSTRACT
The development of agriculture requires the use of microorganisms in the management of phytopathogens as a way to compensate for the use of chemical pesticides, in order to produce healthy crops. The objective of this study was to characterize a new isolate of Trichoderma sp. based on morphological and molecular features, and its potential ability to control the pathogen Alternaria sp. The antagonistic isolate was isolated from soil samples of potato fields in Guasave Sinaloa, Mexico, whereas the pathogen was collected from infected apple leaves in the orchard "La Escondida" in Guerrero County, Chihuahua, Mexico. For morphological characterization both fungi were grown on solid PDA medium. DNA of Trichoderma sp. was isolated using the CTAB method and PCR analyses were done using ITS1, ITS4 primers resulting in amplified products of 600 bp. These were sequenced, submitted to Genbank (acc. no. MN950427) and used for further phylogenetic analysis through Bayesian inference approach. Five clades were identified and the polytome topography recovered from clade 4 indicates a high genetic similarity with T. asperellum. A BLAST examination of the resulting sequence in GenBank showed 98.11% similarity with T. asperellum. This result together with the morphological and the phylogenetic analyses indicates that the isolate belongs to Trichoderma asperellum Samuels, Lieckfeldt & Nirenberg. Biocontrol tests of this isolate showed inhibition of Alternaria sp. between 50% and 93%. These results are essential for biodiversity research and give some new possibilities for pest management.
ABSTRACT
ABSTRACT: Biofortification of food crops is implemented through the application of mineral fertilizers, to improve the levels of essential mineral elements for human nutrition. Magnesium is a key macronutrient in crop production and quality; however, worldwide, it is the most limiting macronutrient in agriculture. Magnesium plays an important role in manipulating physiological and biochemical processes in plants. Therefore, the objective of this study was to evaluate the efficacy of biofortification with magnesium chloride and sulfate on the accumulation of bioactive compounds and antioxidant capacity in snap bean cv. Strike. Two sources of Magnesium were applied via edaphic route: Magnesium chloride and magnesium sulfate at doses of 0, 50, 100 and 200 ppm during 2018 in Mexico. Accumulation of bioactive compounds (total phenols, total flavonoids and total anthocyanins) and antioxidant capacity in snap bean fruits were evaluated. Results obtained indicate that the concentration of total flavonoids, total anthocyanins and antioxidant capacity in the edible parts of snap beans were higher in the MgSO4 treatment than in the MgCl2 treatments, exceeding 30, 59 and 6% respectively. This is one of the first studies on the edaphic agronomic biofortification of Mg+ and its effect on nutraceutical quality in snap bean. An interesting result is that MgSO4 produced high concentrations of anthocyanins in edible snap beans. These results can be applied as a new strategy to reduce malnutrition and improve the health of the population in poor urban and rural communities in developing countries.
RESUMO: A biofortificação de culturas alimentares é implementada através da aplicação de fertilizantes minerais, para melhorar os níveis de elementos minerais essenciais para a nutrição humana. O magnésio é um macronutriente essencial na produção e qualidade das culturas, no entanto, em todo o mundo, é o macronutriente mais limitante da agricultura. O magnésio desempenha um papel importante na manipulação de processos fisiológicos e bioquímicos nas plantas. Portanto, o objetivo deste estudo foi avaliar a eficácia da biofortificação com cloreto e sulfato de magnésio no acúmulo de compostos bioativos e capacidade antioxidante em feijões verdes cv. Strike. Duas fontes de magnésio foram aplicadas por via edáfica: cloreto de magnésio e sulfato de magnésio nas doses de 0, 50, 100 e 200 ppm durante o ano de 2018 no México. Foram avaliados o acúmulo de compostos bioativos (fenóis totais, flavonóides totais e antocianinas totais) e a capacidade antioxidante em frutos de feijão-vagem. Os resultados obtidos indicam que a concentração de flavonoides totais, antocianinas totais e capacidade antioxidante nas partes comestíveis do feijão-vagem foram maiores no tratamento com MgSO4 do que nos tratamentos com MgCl2, ultrapassando 30, 59 e 6% respectivamente. Este é um dos primeiros estudos sobre a biofortificação agronômica edáfica do Mg+ e seu efeito na qualidade nutracêutica do feijão-vagem. Um resultado interessante é que o MgSO4 produziu altas concentrações de antocianinas no feijão-vagem comestível. Esses resultados podem ser aplicados como uma nova estratégia para reduzir a desnutrição e melhorar a saúde da população em comunidades urbanas e rurais pobres em países em desenvolvimento.
