Aumento da tolerância da cana-de-açúcar à deficiência hídrica por meio de bactérias promotoras de crescimento vegetal
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Data
2022-02-24
Autores
Carnietto, Melina Rodrigues Alves [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Dentre os fatores que asseguram o bom desempenho para a cana-de-açúcar, está a absorção de umidade do solo, sendo que um dos principais problemas que afetam a cultura é o déficit hídrico na fase inicial do desenvolvimento. Atualmente o estudo do uso de bactérias promotoras de crescimento vegetal (BPCV) tem apresentado bons resultados a fim de contornar esse problema, conferindo tolerância a estresses bióticos e abióticos, entre outros benefícios. Esse estudo se propôs a investigar os efeitos da deficiência hídrica em cana-de-açúcar discriminando as diferentes respostas biométricas, fisiológicas e bioquímicas da planta aos tratamentos sem e com inoculação de Bacillus subtilis e Bacillus licheniformis. Foi conduzido um experimento em casa de vegetação utilizando a variedade RB855536, em dois tipos de solos, argiloso e arenoso, e dois regimes hídricos (com e sem déficit hídrico), e com e sem BPCV, com seis repetições, num delineamento fatorial em blocos inteiramente casualizados. As BPCV foram aplicadas nas gemas no momento do plantio e o déficit hídrico foi implementado dos 120 aos 135 dias após o plantio (DAP), seguido de reidratação. As avaliações biométricas, fisiológicas e coletas para análises bioquímicas foram realizadas em cinco épocas, dos 118 aos 147 DAP. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste Tukey (P<0,05). As BPCV influenciaram nas trocas gasosas e na densidade estomática, houve redução do conteúdo de pigmentos fotossintéticos e potencial hídrico foliar e ao final das avaliações o teor relativo de água foi superior em tratamentos inoculados. Houve ativação do sistema antioxidante aumentando a atividade da superóxido dismutase, catalase e ascorbato peroxidase, enquanto o conteúdo de prolina foi menor em tratamentos inoculados. As BPCV aumentaram as médias de parâmetros biométricos, como altura das plantas, diâmetro dos perfilhos, comprimento e largura das folhas +1 e +3, número de folhas e área foliar. A inoculação aumentou também, a massa de matéria seca da raiz (MSR) e a massa de matéria seca da parte aérea (MSPA). Observou-se também, redução da razão MSPA/MSR, incrementando o desenvolvimento do sistema radicular em relação a parte aérea. Os efeitos da inoculação foram benéficos em ambos os tipos de solo. A inoculação com Bacillus subtilis e Bacillus licheniformis aumentou a tolerância da cana-de-açúcar à deficiência hídrica por diversos mecanismos.
Among the factors that ensure a good performance for sugarcane is the absorption of soil moisture, and one of the main problems that affect the culture is the water deficit in the initial phase of development. Currently, the study of the use of plant growth-promoting bacteria (PGPB) has shown good results in order to circumvent this problem, conferring tolerance to biotic and abiotic stresses, among other benefits. This study aimed to investigate the effects of water deficit in sugarcane, discriminating the different biometric, physiological and biochemical responses of the plant to treatments without and with inoculation of Bacillus subtilis and Bacillus licheniformis. An experiment was carried out in a greenhouse using the variety RB855536, in two types of soils, clayey and sandy, and two water regimes (with and without water deficit), and with and without PGPB, with six replications, in a block factorial design. entirely randomized. The PGPB were applied to the buds at the time of planting, the water deficit was implemented from 120 to 135 days after planting (DAP), followed by rehydration. Biometric and physiological assessments and collections for biochemical analyzes were performed at five times, from 118 to 147 DAP. Data were submitted to analysis of variance and means were compared by Tukey's test (P<0.05). The PGPB influenced gas exchange and stomatal density, there was a reduction in the content of photosynthetic pigments and leaf water potential, at the end of the evaluations the relative water content was higher in inoculated treatments. There was activation of the antioxidant system increasing the activity of superoxid dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), the proline content was lower in inoculated treatments. The PGPB increased the averages of biometric parameters, such as plant height, tiller diameter, length and width of leaves +1 and +3, number of leaves and leaf area, inoculation increased the dry matter of roots (DMR) and dry matter of aerial part (DMAP), there was a decrease in the DMAP/DMR ratio, increasing the development of the root system in relation to the shoot. The inoculation effects were beneficial in both soil types. Inoculation with Bacillus subtilis and Bacillus licheniformis increased the tolerance of sugarcane under water deficit by several mechanisms.
Among the factors that ensure a good performance for sugarcane is the absorption of soil moisture, and one of the main problems that affect the culture is the water deficit in the initial phase of development. Currently, the study of the use of plant growth-promoting bacteria (PGPB) has shown good results in order to circumvent this problem, conferring tolerance to biotic and abiotic stresses, among other benefits. This study aimed to investigate the effects of water deficit in sugarcane, discriminating the different biometric, physiological and biochemical responses of the plant to treatments without and with inoculation of Bacillus subtilis and Bacillus licheniformis. An experiment was carried out in a greenhouse using the variety RB855536, in two types of soils, clayey and sandy, and two water regimes (with and without water deficit), and with and without PGPB, with six replications, in a block factorial design. entirely randomized. The PGPB were applied to the buds at the time of planting, the water deficit was implemented from 120 to 135 days after planting (DAP), followed by rehydration. Biometric and physiological assessments and collections for biochemical analyzes were performed at five times, from 118 to 147 DAP. Data were submitted to analysis of variance and means were compared by Tukey's test (P<0.05). The PGPB influenced gas exchange and stomatal density, there was a reduction in the content of photosynthetic pigments and leaf water potential, at the end of the evaluations the relative water content was higher in inoculated treatments. There was activation of the antioxidant system increasing the activity of superoxid dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), the proline content was lower in inoculated treatments. The PGPB increased the averages of biometric parameters, such as plant height, tiller diameter, length and width of leaves +1 and +3, number of leaves and leaf area, inoculation increased the dry matter of roots (DMR) and dry matter of aerial part (DMAP), there was a decrease in the DMAP/DMR ratio, increasing the development of the root system in relation to the shoot. The inoculation effects were beneficial in both soil types. Inoculation with Bacillus subtilis and Bacillus licheniformis increased the tolerance of sugarcane under water deficit by several mechanisms.
Descrição
Palavras-chave
Saccharum spp., Déficit hídrico, Inoculação de micro-organismos, Tipos de solo, Estresse, Water deficit, Inoculation os micro-organisms, Soil types, Stress