Loading...
3 results
Search Results
Now showing 1 - 3 of 3
- Chlorella vulgaris and tetradesmus obliquus protect spinach (Spinacia oleracea L.) against fusarium oxysporumPublication . Viana, Catarina; Genevace, Méanne; Gama, Florinda; Guerreiro David Coelho, Luísa Isabel; Pereira, Hugo; Varela, João; Reis, MárioChlorella vulgaris and Tetradesmus obliquus were tested as biocontrol agents against the phytopathogenic fungus Fusarium oxysporum. This evaluation was conducted through in vitro and in vivo trials with spinach (Spinacia oleracea L.). The in vitro trials showed that C. vulgaris and T. obliquus were able to inhibit the phytopathogen, showing a similar inhibitory effect to that of the positive controls (Rovral, BASF (R) and Biocontrol T34, Biocontrol Technologies (R) S.L.). C. vulgaris aqueous suspensions at 3.0 g L-1 led to a hyphal growth of 0.55 cm, each corresponding to a reduction of 63% of fungal growth. With T. obliquus, the hyphal growth was 0.53 cm when applied at a concentration of 0.75 g L-1, having an inhibition of fungus growth of 64%. Thereafter, these results were validated in an in vivo trial on spinach using the same controls. The results revealed a lower severity and disease incidence and a reduction in the disease's AUDPC (area under the disease progress curve) when spinach was treated with the microalgae suspensions. Overall, these findings highlight the potential of C. vulgaris and T. obliquus suspensions as promising biocontrol agents against F. oxysporum in spinach when applied through irrigation.
- Isolation and selection of protein-rich mutants of chlorella vulgaris by fluorescence-activated cell sorting with enhanced biostimulant activity to germinate garden cress seedsPublication . Trovão dos Santos, Mafalda; Schüler, Lisa; Pedroso, Humberto; Reis, Ana; Santo, Gonçalo Espírito; Barros, Ana; Correia, Nádia; Ribeiro, Joana; Bombo, Gabriel; Gama, Florinda; Viana, Catarina; Costa, Monya; Ferreira, Sara; Cardoso, Helena; Varela, João; Silva, Joana; Freitas, Filomena; Pereira, HugoMicroalgae are a promising feedstock with proven biostimulant activity that is enhanced by their biochemical components (e.g., amino acids and phytohormones), which turns them into an appealing feedstock to reduce the use of fertilisers in agriculture and improve crop productivity and resilience. Thus, this work aimed to isolate protein-rich microalgal mutants with increased biostimulant activity. Random mutagenesis was performed with Chlorella vulgaris, and a selection of protein-rich mutants were sorted through fluorescence-activated cell sorting (FACS), resulting in the isolation of 17 protein-rich mutant strains with protein contents 19-34% higher than that of the wildtype (WT). Furthermore, mutant F4 displayed a 38%, 22% and 62% higher biomass productivity, growth rate and chlorophyll content, respectively. This mutant was then scaled up to a 7 L benchtop reactor to produce biomass and evaluate the biostimulant potential of this novel strain towards garden cress seeds. Compared to water (control), the germination index and the relative total growth increased by 7% and 19%, respectively, after the application of 0.1 g L-1 of this bioproduct, which highlights its biostimulant potential.
- Enhancing growth, nutrient uptake and flowering of Tagetes patula plants through the application of suspensions of Chlorella vulgarisPublication . Vieira, João; Saque, Moisés; Viana, Catarina; Rodrigues, Maria Helena; Guerreiro David Coelho, Luísa Isabel; Gama, Florinda; Varela, João; Pereira, Hugo; Reis, Mário; Pestana, Maribela; Correia, Pedro JoséTagetes patula L. is a prominent plant that is frequently used for its ornamental value. Marigolds are sources of various compounds of great interest to agricultural, pharmaceutical, and nutritional industries. Microalgae can be applied as a biostimulant as they have multifunctional properties in agriculture, namely facilitating nutrient uptake, improving crop performance and physiological status, and thus increasing tolerance to abiotic stress. This study evaluated the efect of applying Chlorella vulgaris as a plant biostimulant on the growth and fowering of T. patula plants. Microalgae suspensions were applied to the substrate at concentrations of 0.5, 2.0 and 5.0 g dry weight (DW) L−1. A set of plants without the application of microalgae was used as control. The use of microalgae had a positive impact on plant growth. Specifcally, C. vulgaris application resulted in greater height, while the highest concentration (5.0 g DW L−1) resulted in higher fresh weight. Microalgae application signifcantly promoted the earlier fowering of marigolds. The macronutrient and micronutrient values were statistically similar between the control plants and those treated with microalgae. When considering only the treated plants, there was a signifcant correlation between the concentration of C. vulgaris and the concentrations of N, P, Mn and Cu in the shoots of T. patula plants. Plants receiving higher concentrations of C. vulgaris exhibited higher levels of these nutrients. These results highlight the potential use of Chlorella vulgaris as an efective biostimulant for enhancing the growth, fowering, and nutrient uptake of T. patula, ofering valuable applications for improving ornamental plant production and, ultimately, agricultural sustainability.