Physiological changes in hybrid Brachiaria cv. Mulato II after accelerated aging to overcome dormancy

• Main Authors: Diego de Sousa Pereira, Maria Laene Moreira de Carvalho, Renato Mendes Guimarães, Ariadne Santos Oliveira, Gabriel Abreu Reis
• Format: Article
• Language: English
• Published: Associação Brasileira de Tecnologia de Sementes
• Series: Journal of Seed Science
• Subjects: forage seeds; germination; electrical conductivity; respiration; isoenzymes
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2317-15372017000300244&lng=en&tlng=en

Abstract: To evaluate the effect of accelerated aging to overcome dormancy of hybrid Brachiaria cv. Mulato II (U. brizantha x U. decumbens x U. ruziziensis), seeds were collected from two lots with and without scarification, submitted to 42 °C and high humidity (98%) for different periods (0, 24, 48, 72 and 96 h) and then dried at 30 °C to the humidity of 9.1%. The physiological changes were evaluated by tetrazolium, germination, electrical conductivity, respiratory activity and enzymatic evaluation. The exposure of the hybrid Brachiaria cv. Mulato II to accelerated aging at 42 °C and 98% relative air humidity for up to 96 hours does not alter its viability by the tetrazolium test. Accelerated aging at 42 °C and 98% of humidity for up to 48 hours favors the germination of the scarified seeds of hybrid Brachiaria cv. Mulato II, with increased expression of α-amylase enzyme and reduction of electrical conductivity values. Loss of vigor occurs in scarified seeds of hybrid Brachiaria cv. Mulato II when exposed to accelerated aging at 42 °C and 98% of humidity from 96 hours with consequent changes in enzymatic systems and increased of the respiratory rate.