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

Abstract

Although knowledge about halophytic Solanaceae is scarce, it is known that several species within genus Lycium tolerate salinity. Lycium humile grows in highly saline soils in mudflats near saline Andean lakes. This study evaluated the germination responses of L. humile under different scarification methods, photoperiods, temperatures and saline conditions and, simultaneously, tested seedling survival under different iso-osmotic conditions. Dormancy and germination were found to be regulated by interactions with different factors, with the highest germination percentages being obtained by immersion in sulfuric acid, with a temperature of 25 °C and a temperature regime of 5/25 °C, under which seeds were neutrally photoblastic. 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 seed tolerance to salinity may determine the occurrence and restricted distribution of L. humile.

Germination and sustainable cultivation of succulent halophytes using resources from a degraded estuarine area through soil technologies approaches and saline irrigation water

“…cretica (Etemadi et al, 2020), and L . humile (Palchetti et al, 2020). Nonetheless, in all these studies, the treatment duration was longer than in the present paper.…”

“…However, few works have addressed the H 2 O 2 role in halophytes' germination: Suaeda fruticosa (Hameed et al, 2009), Chenopodium quinoa (Hajihashemi et al, 2020), and Zygophyllum simplex (Hussain et al, 2022). The sulfuric acid (H 2 SO 4 ) is commonly applied in the chemical scarification of seeds with a thick coat such as Suaeda maritima (Mariko et al, 1992), Prosopis juliflora (Zare et al, 2011), Cressa cretica (Etemadi et al, 2020), and Lycium humile (Palchetti et al, 2020).…”

Germination Response of Datura stramonium L. to Different pH and Salinity Levels under Different Temperature Conditions

“…Although data are scarce in the literature, there is some information on other species of the Solonaceae family that can tolerate some extreme salinity levels. Lycium humile , for example, can tolerate salinity up to 60 dS/m and germinate [ 41 ], while some other species, such as Physalis angulata and Physalis philadelphica var. immaculata , can tolerate up to 40 dS/m [ 42 ].…”

Living in extreme environments: distribution of Lycium humile (Solanaceae), an endemic halophyte from the Altiplano-Puna region, South America

“…Thus, L. humile is one of the few vascular plant species growing at these edges since, even though the water table is near to the surface, plants need to cope with high salinity (> 200 mM NaCl) that promote physiologically dry soils. Halophytes, like L. humile , are the only plants able to grow in these environments because they have different mechanisms that enhance root water uptake by decreasing their water potential ( Palchetti et al 2020 ).…”