ENVELHECIMENTO ACELERADO PARA AVALIACAO DO VIGOR DE SEMENTES DE Parapiptadenia rigida

Abstract

RESUMOA utilização de procedimentos eficientes para análise de sementes é fundamental para programas de controle de qualidade, auxiliando na escolha dos materiais de maior potencial para a produção de mudas, assim como para o monitoramento durante o armazenamento de sementes. O objetivo desta pesquisa foi identificar procedimentos adequados para o teste de envelhecimento acelerado para avaliação do vigor de sementes de Parapiptadenia rigida. Três lotes de sementes foram avaliados quanto ao teor de água e a germinação e vigor, por meio dos testes de condutividade elétrica, comprimento, massa fresca e seca de plântulas e com o teste de envelhecimento acelerado realizado com diferentes metodologias. Os resultados obtidos permitiram concluir que os testes de envelhecimento acelerado à 38°C por 24, 48 ou 72 horas e 41°C por 24 horas são eficientes na avaliação do vigor de sementes de Parapiptadenia rigida. PALAVRAS-CHAVE: angico, qualidade de sementes, tecnologia de sementes. ACCELERATED AGING TEST TO EVALUATE Parapiptadenia rígida SEED VIGORABSTRACT The use of efficient procedures for seed analysis is essential for quality control programs, helping to select the materials with the greatest potential for seedling production, as well as for monitoring during seed storage. The objective of this research was to identify appropriate procedures of accelerated aging test to evaluate Parapiptadenia rigida (Benth.) Brenan seed vigor. Parapiptadenia rigida seeds represented by 3 lots. Seed moisture content was measured and germination capacity were evaluated; seed vigor was evaluated by electrical conductivity, seedling length, fresh and dry seedling weight obtained after seedling length test and with different accelerated aging tests. Results showed that Parapiptadenia rigida seed vigor can be evaluated efficiently by accelerated aging tests, using combinations of 38 ° C for 24, 48 or 72 hours and 41 ° C for 24 hours.

Seed vigor of Piptadenia moniliformis Benth. subjected to thermal stress

“…Salt, by limiting the evaporation of water molecules, contributed to a lower water content, thus reflecting a lower degree of deterioration, i.e., a greater vigor, as can be observed by germination values and germination speed index. Temperatures above 40°C are known to cause protein denaturation, both structural and enzymatic, causing changes in the degradation and mobilization of stored seed reserves, thus reducing the energy available for germination (Dotto & Silva, 2017).…”

“…This test aims to evaluate seed resistance after a period of exposure to high temperatures and relative humidity (Marcos Filho, 2015). Temperatures above 40°C are known to cause a decreased capacity for RNA and protein biosynthesis, mitochondrial degeneration, increased chromosome fragmentation, membrane lipid peroxidation, and enzymatic changes such as reduced activity of lipases, amylases, proteases, peroxidases, among others (Dotto & Silva, 2017;Bewley, Bradford, Hilhorst, & Nonogaki, 2013;Mahjabin & Abidi, 2015). This results in a decreased germination speed and percentage, as well as in an increased formation of abnormal seedlings (Marcos Filho, 2015).…”