Viabilidade De Sementes De Castanha-Do-Brasil Pelo Teste De Tetrazólio

Abstract

Objetivou-se revisar e propor o protocolo de viabilidade das sementes da Bertholletia excelsa pelo teste de tetrazólio. Sementes oriundas de plantio comercial propagado por enxertia com 16 anos de idade implantadas na Fazenda Iracema em Cláudia, MT, foram destegumentadas e cortadas longitudinalmente, depois foram hidratadas em água por imersão direta (ID) e papel toalha Germitest® (PG) por 24 e 48 h e embebidas nas concentrações de 0,1 e 0,5% do sal de tetrazólio por 12 e 24 h no escuro à 30 °C. O delineamento experimental foi completamente randomizado em fatorial 2 x 2 x 2 x 2 (forma de embebição x tempo em embebição x tempo em solução de tetrazólio x concentração da solução de tetrazólio) com quatro repetições de 8 sementes. O teste de tetrazólio foi eficiente para colorir e identificar as sementes viáveis e inviáveis. A avaliação da viabilidade das sementes da B. excelsa destegumentadas e partidas ao meio foi melhor na condição de embebição com imersão direta em água por 24 h e concentração de 0,5% do sal tetrazólio por 24 h à 30 °C e embebição em papel toalha Germitest® por 24 h e concentração de 0,5% do sal tetrazólio por 12 h à 30 °C.Palavras-chave: Bertholletia excelsa Humb. Bonpl; potencial fisiológico; sementes florestais; recalcitrância. VIABILITY OF BRAZIL NUTS SEEDS BY TETRAZOLIUM TEST ABSTRACT: The objective was to review and propose the protocol of viability of Bertholletia excelsa seeds by tetrazolium test. Seeds from the commercial planting propagated by grafting with 16-year-old implanted at Fazenda Iracema in Cláudia, MT, were undegumented and cut longitudinally, then hydrated in water by direct immersion (ID) and Germitest® paper towel (PG) for 24 and 48 h and soaked in concentrations of 0.1 and 0.5% of tetrazolium salt for 12 and 24 h in the dark at 30 ° C. The experimental design was completely randomized in a factorial design 2 x 2 x 2 x 2 (soaking form x soaking time x time in tetrazolium solution x tetrazolium solution concentration) with four replications of 8 seeds. The tetrazolium test was efficient to color and identify viable and unviable seeds. The evaluation of viability of detegumented and cut longitudinally B. excelsa seeds was better in: direct soaking in water for 24 h and concentration of 0.5% of tetrazolium salt for 24 h at 30 ° C and soaking in Germitest® paper towels for 24 h and a concentration of 0.5% of the tetrazolium salt for 12 h at 30 ° C.Keywords: Bertholletia excelsa Humb. Bonpl; physiological potential; forest seeds; recalcitrance.

Bertholletia excelsa SEEDS IN THE CERRADO-AMAZON TRANSITION REGION: MORPHOMETRY, COLORIMETRY, VIABILITY, AND GERMINATION

“…A longitudinal cut between the poles of each seed was made for imbibition in 200 mL of distilled water by direct immersion inside Gerbox boxes placed in a BOD chamber at 30 °C without photoperiod for 24 hours. The hydration of seeds was carried out by imbibition in the tetrazolium solution, at the concentration of 0.5% for 24 hours, in a dark environment at 30 °C, as recommended by Borella et al (2020). After applying the treatments, the seeds were washed in running water and kept on moistened paper towel until the end of the evaluations.…”

“…Natural regeneration of this species is dependent not only on fauna activity and management practices, such as opening of canopy and trails, enrichment of native areas with seedlings, and removal of lianas in trunks and crowns of Brazil nut trees (SCOLES; GRIBEL, 2012), but also on physiological quality of seeds, which is connected with embryo maturity regulated by hormonal balance (CAMARGO et al, 2000) and environmental humidity conditions during dispersal (WADT et al, 2018;BORELLA et al, 2020). Therefore, understanding seed morphophysiological characteristics is important for the propagation and conservation of this species.…”