Gibberellic acid provides greater tolerance to saline stress in cactus seed germination

Abstract

It is important to understand the ecophysiological behavior and develop techniques applicable to conservation measures of species that inhabit arid and semi-arid ecosystem and are exposed to adverse environmental conditions. The objective of this study was to evaluate the effects of gibberellic acid (GA3) application during seed germination under saline stress conditions of a cactus. Pilosocereus gounellei susbp gounellei seeds were submitted to NaCl saline solutions at osmotic potentials of 0.0,-0.3,-0.6 and-0.9 MPa. For each osmotic potential, GA3 concentrations of 0, 100, 200 and 300 ppm were used. The results indicated that salt stress reduces germination percentage and synchronization as seeds are submitted to more negative osmotic potentials, as well as delaying germination time. However, this negative effect of NaCl was reversed when the seeds were subjected to the specific concentration of 100 ppm of gibberellic acid. Therefore, our study demonstrated that the application of GA3 at specific concentration improves the germinative metabolism of cactus seeds and promotes the acquisition of tolerance to saline stress conditions by increasing germinability, reducing germination time and increasing synchronization, thus representing a viable technique for seed germination and seedlings production under adverse environmental conditions. Highlighted Conclusions 1. The application of GA3 at specific concentration improves the germinative metabolism of cactus seeds and promotes the acquisition of tolerance to saline stress conditions. 2. The application of GA3 represents a viable technique for seed germination and seedlings production under adverse environmental conditions.

Germination of Cactus Seeds Under Saline Stress

“…jamacaru (MEIADO et al, 2010), Pilosocereus arrabidae (MARTINS et al, 2012), Pilosocereus catingicola subsp. salvadorensis (LIMA; MEIADO, 2017) MEIADO, 2020). These studies pointed out important considerations on seed germination conditioning.…”

Emprego de água biossalina na germinação de sementes de espécies florestais da Caatinga – uma revisão

“…Em geral, o número de artigos sobre o uso de águas biossalinas no processo de germinação de sementes de espécies florestais da Caatinga é consideravelmente baixo (Figura 2). Isto evidencia a carência de estudos sobre o manejo e análise de sementes florestais da Caatinga nas diversas situações de estresse salino e como o mesmo influencia no processo germinativo (Lima, Oliveira, & Meiado, 2020). Além disso, na Caatinga, floresta tropical seca, estão presentes além da salinidade, o déficit hídrico, a elevada intensidade luminosa, as altas temperaturas, as baixas precipitações e umidade relativa do ar, associadas à elevada taxa de evaporação; sendo que em conjunto tais condições contribuem para um ambiente altamente estressante para as sementes e estabelecimento inicial das plântulas (Tavares Filho et al, 2010).…”