Espécies de Piper frente à diferentes tipos de estresses bióticos e abióticos

• Autor(a) principal: Cerri Neto, Basílio
• Data de Publicação: 2024
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/17355
• topic: Área(s) do conhecimento do documento (Tabela CNPq); Piperaceae; enxertia; fusariose; fotossíntese; déficit hídrico; alagamento; subject.br-rjbn

Brazil is the third largest global producer of black pepper. Despite the economic importance of black pepper, Brazilian production faces significant challenges. Average yield is notably low, with both biotic and abiotic factors impacting productivity. Among the biotic factors, the fungus Fusarium solani f. sp. Piperis, which causes fusariosis, which attacks the root system and can lead to the death of plants. Abiotic factors, such as water deficit and flooding, also drastically reduce production. Resistance to water stress is crucial to face these challenges. Reducing growth in response to resource constraints is a common strategy. Furthermore, flooding represents another concern for producers. Stressed plants save energy for survival, adjusting the distribution of photoassimilates until conditions return to normal. Soil-borne diseases such as fusariosis pose a significant threat to black pepper plantations around the world. Fusarium solani f. sp. Piperis colonizes xylem vessels, interrupting the transport of water and nutrients. Gas exchange assessments were carried out using Irga, chlorophyll a flowering, photosynthetic pigment content, growth and mass accumulation and anatomy analyzes were also carried out. After the drought cycles, there was a reduction in the polar diameter of the stomata in P. tuberculatum and in the equatorial diameter in P. aduncum. Stomatal density was increased in P. tuberculatum during drought. At T0, the values of photosynthetic performance indexes related to absorption were higher, with a reduction in rehydration. Photosynthetic performance indices showed a drastic reduction in the ‘Balankota’ genotype. P. tuberculatum and Bragantina showed a reduction in stomatal density in flooding when compared to the control. Flooding led to an increase in the polar diameter of the stomata in 'Bragantina', 'Kottanadan' and P. tuberculatum. Among the inoculated plants, P. caldense, P. aduncum, P. tuberculatum and P. hispidum showed an increase in the photochemical quantum yield for heat dissipation and 'Kottanadan' showed a reduction. At the end of the experiment, the survival rate was higher in plants grafted onto Piper caldense (38.88%), followed by ‘Bragantina’ (11.11%), Piper aduncum showed the lowest survival rate (7.41%). There was a reduction in the rate of photosynthesis in the ‘Kottanadan’ genotype in the inoculated plants. Among the species studied, P. aduncum was the only one that showed significant differences in relation to the other species. P. caldense had the highest survival percentage and P. aduncum had the lowest survival. It is concluded that plants in drought cycles showed alarm that consequently activated escape mechanisms to tolerate stress, P. tuberculatum showed more alarm signals and memory in the face of stress. It is concluded that plants in drought cycles showed alarm that consequently activated escape mechanisms to tolerate stress, P. tuberculatum showed more alarm signals and memory in the face of stress.