Osmotic treatment, growth regulator and rooter in Tabebuia roseoalba (RIDL.) Sandwith seeds for direct sowing

Abstract

Direct seeding is a technology that reduces the costs of forest restoration projects and favors species which are difficult to establish for seedlings. The seeds osmotic treatment to accelerate and standardize germination and induce tolerance to environmental stresses may favor seedling establishment in field through direct sowing and contribute to the greater efficiency of this technique. With the purpose of favor seed germination and seedling establishment under direct seeding conditions in the field, Tabebuia roseoalba osmoprimed seeds in polyethylene glycol (PEG) solution and unconditioned seeds were treated with isolated and/or combined solutions of plant growth regulators (PGR) and rooting (RTG). These seeds were submitted to germination test and evaluated for percentage germination rate, germination speed index and normal seedlings, and to seedling emergence test by direct field seeding. RTG had a toxic effect on T. roseoalba seeds. Osmoconditioning induced stress tolerance by RTG during germination and on seedling establishment. PGR treatment favors seedling emergence in field conditions and alleviates the toxicity effect caused by RTG. These treatments have great potential for use in direct sowing of T. roseoalba seeds.

Physiological potential of piquin pepper seeds in response to pregermination treatments

“…The genetic variability present in the wild populations of piquin pepper, expressed in the morphological characteristics of plants and fruits, has hampered the finding of a general pregermination treatment protocol. Despite the advancements made in the knowledge about the germination of chili pepper seeds, the imbibition behavior of seeds in conditioning solutions, the distribution of solutes in their tissues, and the response and action mechanisms of plant growth hormones remain unclear (Terskikh et al, 2011;Silva et al, 2020). For that reason, our objective in this study was to evaluate the effect of pregermination treatments based on growth regulators, sulfuric acid, and Biozyme solutions at different immersion periods on the imbibition and germination of piquin pepper seeds.…”