Desenvolvimento de formulações de Trichoderma para uso na promoção de crescimento de plantas e controle de Sclerotinia sclerotiorum
Data
2022-11-29
Autores
Silva, Lucas Guedes [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Fungos do gênero Trichoderma apresentam um complexo arsenal de mecanismos envolvidos na proteção de plantas, os quais incluem supressão de fitopatógenos, promoção de crescimento e mitigação de estresses abióticos em plantas. Para tanto, a seleção dos isolados é de fundamental importância, pois Trichoderma spp. são altamente diversificadas em eficácia na supressão de patógenos de plantas, apresentando respostas variadas de acordo com as cepas que estão sendo confrontadas. Outros desafios são relacionados à multiplicação, ao armazenamento, e ao desenvolvimento de formulações estáveis e com vida de prateleira adequada. Vencer esses desafios colaborará para a disponibilização de produtos com qualidade adequada no mercado. O presente trabalho teve como objetivos selecionar isolados de Trichoderma spp. promotores de crescimento em algodoeiro e inibidores da germinação de escleródios de Sclerotinia sclerotiorum; otimizar a produção de Trichoderma asperelloides em farinha de arroz e; desenvolver formulações granulares à base de farinha de arroz. Trichoderma asperelloides CMAA 1584 apresentou maior eficiência no controle de Sclerotinia sclerotiorum, enquanto o efeito bioestimulante no crescimento do algodoeiro foi mais pronunciado com Trichoderma lentiforme CMAA 1585. Na otimização da produção de Trichoderma asperelloides na farinha de arroz, o teor de nitrogênio (0,1% p/p) e o tipo de fermentador (Erlenmeyer) tiveram efeitos significativos na obtenção de maiores rendimentos, enquanto a melhor fonte de nitrogênio foi a levedura hidrolisada (Hilyses®). As formulações GControle, GBreak-Thru, GBentonita e GComposto orgânico + Break-Thru foram as que formaram o maior número de unidades formadoras de colônia g-1 (UFC g-1) após reidratação em ágar-água. A viabilidade à temperatura ambiente foi mantida estável por até 3 meses nas formulações GControle e GBentonita, enquanto em condições refrigeradas a viabilidade foi mantida por 12 meses nas formulações GBentonita e GComposto orgânico + Break Thru. Não foram observadas diferenças significativas na inibição da germinação miceliogênica de escleródios de Sclerotinia sclerotiorum no solo pela aplicação da formulação GControle nas doses de 5 × 104, 5 × 105 ou 5 × 106 UFC g-1 de solo, mantendo um índice de controle de escleródios em 79,2; 87,5; e 93,7%, respectivamente. Desta forma, pode ser considerado que Trichoderma asperelloides CMAA 1584 apresenta a maior eficiência no controle de Sclerotinia sclerotiorum, enquanto Trichoderma lentiforme CMAA 1585 apresenta a maior promoção de crescimento das plantas, podendo a mistura de ambos ser usada para o controle do patógeno e como bioestimulante em plantas de algodão.
Fungi of the genus Trichoderma present a complex arsenal of mechanisms involved in plant protection, which include suppression of plant pathogens, growth promotion and mitigation of abiotic stresses in plants. Therefore, the selection of potential isolates must be performed carefully, as Trichoderma spp. are highly diversified in effectiveness in suppressing plant pathogens, showing varied responses according to the strains being confronted. Other challenges are related to multiplication, storage, and development of stable formulations with adequate shelf life. Overcoming these challenges will help make products of adequate quality available on the market. The objectives of this study were to select Trichoderma spp. strains growth promoters in cotton and with biocontrol activity against sclerotia of Sclerotinia sclerotiorum, to optimize the production of Trichoderma asperelloides in rice flour, and to develop granular formulations based on rice flour. Trichoderma asperelloides CMAA 1584 is more efficient in controlling Sclerotinia sclerotiorum, while the biostimulating effect on cotton growth was more pronounced with Trichoderma lentiforme CMAA 1585. In optimizing the production of Trichoderma asperelloides in rice flour, the nitrogen content (0.1% w/w) and the type of fermenter (Erlenmeyer flasks) had significant effects in obtaining higher yields, while hydrolyzed yeast (Hilyses®) was the best source of nitrogen. The formulations GControl, GBreak-Thru, GBentonite and GOrganic compost + Break-Thru were those that formed the highest number of colonies forming unit g-1 (CFU g-1) after rehydration in water-agar. Viability at room temperature was maintained stable for up to 3 months in GControl and GBentonite formulations while under refrigerated conditions, viability was maintained for 12 months in GBentonite and GOrganic compost + Break-Thru formulations. No significant differences were observed in the inhibition of the mycelogenic germination of Sclerotinia sclerotiorum in soil by the application GControl formulation at doses of 5 × 104, 5 × 105 or 5 × 106 CFU g-1 of soil, maintaining a sclerotia control index of 79.2; 87.5; and 93.7%, respectively. Thus, Trichoderma asperelloides is more efficient in controlling Sclerotinia sclerotiorum, while Trichoderma lentiforme is more suitable as a biostimulant in cotton plants.
Fungi of the genus Trichoderma present a complex arsenal of mechanisms involved in plant protection, which include suppression of plant pathogens, growth promotion and mitigation of abiotic stresses in plants. Therefore, the selection of potential isolates must be performed carefully, as Trichoderma spp. are highly diversified in effectiveness in suppressing plant pathogens, showing varied responses according to the strains being confronted. Other challenges are related to multiplication, storage, and development of stable formulations with adequate shelf life. Overcoming these challenges will help make products of adequate quality available on the market. The objectives of this study were to select Trichoderma spp. strains growth promoters in cotton and with biocontrol activity against sclerotia of Sclerotinia sclerotiorum, to optimize the production of Trichoderma asperelloides in rice flour, and to develop granular formulations based on rice flour. Trichoderma asperelloides CMAA 1584 is more efficient in controlling Sclerotinia sclerotiorum, while the biostimulating effect on cotton growth was more pronounced with Trichoderma lentiforme CMAA 1585. In optimizing the production of Trichoderma asperelloides in rice flour, the nitrogen content (0.1% w/w) and the type of fermenter (Erlenmeyer flasks) had significant effects in obtaining higher yields, while hydrolyzed yeast (Hilyses®) was the best source of nitrogen. The formulations GControl, GBreak-Thru, GBentonite and GOrganic compost + Break-Thru were those that formed the highest number of colonies forming unit g-1 (CFU g-1) after rehydration in water-agar. Viability at room temperature was maintained stable for up to 3 months in GControl and GBentonite formulations while under refrigerated conditions, viability was maintained for 12 months in GBentonite and GOrganic compost + Break-Thru formulations. No significant differences were observed in the inhibition of the mycelogenic germination of Sclerotinia sclerotiorum in soil by the application GControl formulation at doses of 5 × 104, 5 × 105 or 5 × 106 CFU g-1 of soil, maintaining a sclerotia control index of 79.2; 87.5; and 93.7%, respectively. Thus, Trichoderma asperelloides is more efficient in controlling Sclerotinia sclerotiorum, while Trichoderma lentiforme is more suitable as a biostimulant in cotton plants.
Descrição
Palavras-chave
Biofungicida, Biofertilizante, Formulação, Mofo-branco, Fermentação sólida, Biofungicide, Biofertilizer, Formulation, White mold, Solid-state fermentation