Germination and osmotic adjustment in Salvia hispanica L. (Lamiaceae) seedlings under water and thermal stress

Abstract

Salvia hispanica seedlings have stood out for their potentialities in nutrients for agri-food industries. Nevertheless, studies related to this species are still scarce, especially with respect to agronomic factors that enable its propagation and development. Hence, this study aimed to evaluate germination, vigor and osmotic adjustment of S. hispanica seeds and seedlings subjected to water and thermal stress. The experimental design was completely randomized, with treatments arranged in factorial scheme, corresponding to five levels of polyethylene glycol (PEG 6000) (0.0; -0.1; -0.2; -0.3 and -0.4 MPa) and five temperatures (20, 25, 30 and 20-30 °C), with four replicates of 50 seeds in each treatment. Germination test was set on blotter paper, moistened with PEG 6000 solutions at the previously mentioned potentials, under 8-h photoperiod. The following variables were analyzed: germination, germination speed index, seedling shoot length, seedling root length, seedling dry matter and contents of chlorophyll, carotenoids, amino acids, proline and sugars. Polyethylene glycol levels of -0.4 MPa at all temperatures and -0.3 MPa at 30 °C and 20-30 °C enable germination and vigor of S. hispanica seedlings. S. hispanica seedlings are able to perform osmotic adjustment under water stress conditions up to the level of -0.3 MPa, when grown from seeds germinated at temperatures of up to 25 ºC.

Pre-germination treatments in pitaya (Hylocereus spp.) seeds to attenuate salt stress

“…On the other hand, H. costaricensis seedlings had an increase in their primary root length under salt stress, except for those grown from seeds treated with gibberellic acid, which had greater investment in shoots than in roots. With the decrease in osmotic potential there was also a greater increase in primary root protrusion and lower shoot production in chia (Salvia hispanica L.) seedlings (PAIVA et al, 2019). Also according to these authors, the results obtained can be attributed to the tolerance mechanism of the species, increasing radicle growth in search of water in the substrate.…”

Germinação e crescimento de mudas de Salvia officinalis L. cultivadas com mistura de vermiculita

“…Pesquisas relacionadas à germinação de sementes expostas a estresses são de grande relevância, pois permitem o estudo dos limites de tolerância e adaptação das plantas sujeitas a fatores estressantes (PAIVA et al, 2019).…”