Germination responses of Lycium humile, an extreme halophytic Solanaceae: understanding its distribution in saline mudflats of the southern Puna

PALCHETTI, M.V.; LLANES, A.; REGINATO, M.; BARBOZA, G.E.; LUNA, V.; CANTERO, J.J.

ACTA BOTANICA BRASILICA

SOC BOTANICA BRASIL

Lugar: San Pablo; Año: 2020 vol. 34

0102-3306

Although knowledge about halophytic Solanaceae is scarce, it is known that several species within genus Lycium tolerate salinity. Lycium humile grows in mudflats near to Andean saline lakes in highly saline soils. In this study, germination responses of L. humile were evaluated under different scarification methods, photoperiods, temperatures and saline conditions and, simultaneously, seedling survival was tested under different iso-osmotic conditions. Results showed that dormancy and germination are regulated in interaction with different factors, thus, the highest germination percentages were obtained by immersion in sulfuric acid, with a temperature of 25°C and a temperature regime of 5/25°C, seeds were neutrally photoblastic at this regime. As osmotic potential of saline solutions decreased, germination also decreased drastically but the seedling survival percentage was higher than 30% at 600 mM NaCl. No seeds germinated in any of the polyethylene glycol (PEG) solutions and no seedling survival was observed from -1.2 MPa PEG solutions. More than 90% of seeds incubated in NaCl were able to recover germination after being transferred to distilled water, independently of NaCl treatments. We concluded that the effects of extreme environmental conditions on germination responses and the seed tolerance to salinity may determine the occurrence and restricted distribution of L. humile.