Aplicação de silício e coinoculação com fungos micorrízicos e bactérias em feijoeiro submetido a deficiência hídrica
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Data
2022-08-29
Autores
Guimarães, Mara Lúcia Cruz de Souza
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Universidade Estadual Paulista (Unesp)
Resumo
A crescente demanda por produção de alimentos e a importância de se produzir com maior eficiência do uso de água exige alternativas que possam mitigar efeitos da deficiência hídrica em plantas. Deste modo, o objetivo desta pesquisa foi analisar o efeito de associações de bioestimulantes (BE) nas características morfológicas, fisiológicas e bioquímicas em plantas de feijoeiro (Phaseolus vulgaris L. cv IAC Imperador) submetidas a deficiência hídrica. A pesquisa foi realizada em dois ciclos de cultivo em ambiente protegido: ciclo 1 (outono) e ciclo 2 (primavera – verão). Os tratamentos foram delimitados com objetivo de simular duas condições hídricas do estádio do florescimento até o final do ciclo: CC (irrigações realizadas para voltar a tensão de água no solo para a capacidade de campo – 6 a 10 kPa) e DH (irrigações realizadas para manter a tensão de água no solo entre 40 a 50 kPa – Deficiência hídrica) e três associações de BE: A0 (sem aplicação de BE); A1 (Si - silício + BPCV - bactérias promotoras de crescimento vegetal) e A2 (Si + BPCV + FMA - fungos micorrízicos arbusculares). O manejo da irrigação foi realizado via tensiometria, sendo que as BPCV e FMA foram aplicadas via coinoculação de sementes e o silício foi aplicado no sulco de sementes. As espécies das BPCV foram: Bacillus pumilus, B. subtilis, B. amyloliquefaciens e Rodopseudomonas palustres e as espécies de FMA: Rizophagus irregulares (Glomus spp.) e a fonte de Si utilizado foi SiO2. A DH causou impactos negativos nas plantas, reduzindo parâmetros biométricos, fisiológicos, aumento na concentração de osmólitos e atividade das enzimas antioxidativas; promoveu ainda redução no acúmulo de nutrientes foliares e decréscimo nos componentes da produção. As associações A1 e A2 mitigaram os efeitos da DH nas plantas, promovendo melhoria dos mecanismos fisiológicos. A manutenção do conteúdo relativo de água, aumento da taxa fotossintética, redução da produção de radicais livres, menor perda de eletrólitos contribuíram para maior crescimento e desenvolvimento das plantas, e maior eficiência nos dois ciclos analisados. A produtividade das plantas sob CC e DH, nas associações A1 e A2, foi maior que as plantas sem aplicação de BE sob as mesmas condições hídricas. Assim, o uso da associação de BE à base de Si, BPCV e FMA foram eficientes para reduzir a influência negativa da DH imposta do florescimento ao final do ciclo das plantas.
The growing demand for food production and the importance of producing with more efficient water use require alternatives that can mitigate the effects of water deficiency on plants. Thus, the objective of this research was to analyze the effect of the biostimulant (BE) associations on morphological, physiological, and biochemical characteristics in common bean plants (Phaseolus vulgaris L. cv IAC Imperador) submitted to water deficiency. The research was carried out in two cycles of cultivation in a protected environment: cycle 1 (autumn) and cycle 2 (spring - summer). The treatments were delimited in order to simulate two water conditions of the flowering stage until the end of the cycle: FC (irrigations performed to return the soil water tension to field capacity - 6 to 10 kPa) and WD (irrigations performed to maintain soil water tension between 40 to 50 kPa - Water deficiency) and three associations of BE: A0 (without application of BE); A1 (Si - silicon + PGPB - plant growth promoting bacteria) and A2 (Si + PGPB + AMF - arbuscular mycorrhizal fungi). The irrigation management was performed via tensiometry, and the PGPB and AMF were applied via seed coinoculation and silicon was applied in the furrow of seeds. The species of PGPB were: Bacillus pumilus, B. subtilis, B. amyloliquefaciens, and Rodopseudomonas palustres, and the species of AMF: Rizophagus irregulares (Glomus spp.) and the source of Si used as SiO2. WD caused negative impacts on plants, reducing biometric, and physiological parameters, increase in osmolyte concentration and activity of antioxidative enzymes, promoting a reduction in leaf nutrient accumulation, and a decrease in production components. Associations A1 and A2 mitigated the effects of WD on plants, promoting the improvement of physiological mechanisms. The maintenance of relative water content increased photosynthetic rate, reduction of free radical production, less loss of electrolytes contributed to greater growth and development of the plants, and greater efficiency in the two cycles analyzed. The productivity of plants under FC and WD, in associations A1 and A2, was higher than plants without BE application under the same water conditions. Thus, the use of the association of BE based on Si, PGPB and AMF were efficient to reduce the negative influence of WD imposed from flowering to the end of the plant cycle.
The growing demand for food production and the importance of producing with more efficient water use require alternatives that can mitigate the effects of water deficiency on plants. Thus, the objective of this research was to analyze the effect of the biostimulant (BE) associations on morphological, physiological, and biochemical characteristics in common bean plants (Phaseolus vulgaris L. cv IAC Imperador) submitted to water deficiency. The research was carried out in two cycles of cultivation in a protected environment: cycle 1 (autumn) and cycle 2 (spring - summer). The treatments were delimited in order to simulate two water conditions of the flowering stage until the end of the cycle: FC (irrigations performed to return the soil water tension to field capacity - 6 to 10 kPa) and WD (irrigations performed to maintain soil water tension between 40 to 50 kPa - Water deficiency) and three associations of BE: A0 (without application of BE); A1 (Si - silicon + PGPB - plant growth promoting bacteria) and A2 (Si + PGPB + AMF - arbuscular mycorrhizal fungi). The irrigation management was performed via tensiometry, and the PGPB and AMF were applied via seed coinoculation and silicon was applied in the furrow of seeds. The species of PGPB were: Bacillus pumilus, B. subtilis, B. amyloliquefaciens, and Rodopseudomonas palustres, and the species of AMF: Rizophagus irregulares (Glomus spp.) and the source of Si used as SiO2. WD caused negative impacts on plants, reducing biometric, and physiological parameters, increase in osmolyte concentration and activity of antioxidative enzymes, promoting a reduction in leaf nutrient accumulation, and a decrease in production components. Associations A1 and A2 mitigated the effects of WD on plants, promoting the improvement of physiological mechanisms. The maintenance of relative water content increased photosynthetic rate, reduction of free radical production, less loss of electrolytes contributed to greater growth and development of the plants, and greater efficiency in the two cycles analyzed. The productivity of plants under FC and WD, in associations A1 and A2, was higher than plants without BE application under the same water conditions. Thus, the use of the association of BE based on Si, PGPB and AMF were efficient to reduce the negative influence of WD imposed from flowering to the end of the plant cycle.
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Palavras-chave
estresse hídrico, bactérias promotoras de crescimento vegetal, fungos micorrízicos arbusculares, atenuadores de estresse, Phaseolus vulgaris L., water stress, plant growth promoting bacteria, arbuscular mycorrhizal fungi, stress attenuators