Effects of Four-Week Exposure to Salt Treatments on Germination and Growth of Two Amaranthus Species

Abstract

Soil salinity represents one of the most restrictive environmental factors for agriculture worldwide. In the present study, the salt tolerance of two weeds of the genus Amaranthus, A. albus and A. hybridus, the latter cultivated as green vegetable in Africa, were analysed. Both species showed a remarkable salt tolerance phenotype during germination and vegetative growth. To evaluate the percentage and rate of germination, seeds were germinated in Petri dishes in a germination chamber under increasing concentrations up to 300 mM NaCl. Higher concentrations of salt ranging from 150 to 600 mM NaCl were applied for one month to plants grown in individual pots in the greenhouse. All seeds of A. albus germinated in the control and almost half of the seeds under 200 mM NaCl, but only 4% of the seeds under 250 mM NaCl. In A. hybridus, germination was considerably lower in all treatments and was completely prevented at 250 mM NaCl. The plant growth of both species was severely affected by high salt concentrations of 450 and 600 mM NaCl, but not under lower concentrations. At this stage of the biological cycle, A. hybridus showed a higher salt tolerance, as indicated by the smaller reduction in its growth parameters. The dry weight of leaves and roots of plants receiving 600 mM NaCl decreased in comparison to control: less than 60% in A. hybridus but more than 70% in A. albus. The salt tolerance of the two species contributes to their invasive potential, but on the other hand represents a useful trait when considering them as potential crops for the future.

Comparative Analysis of Tolerance to Salt Stress and Water Deficit in Two Invasive Weeds of the Genus Erigeron (Asteraceae)

“…Germination time (MGT) did not vary from the control. Salt and osmotic stress tolerance were reported in other invasive weeds of different genera, such as, Araujia [ 15 ], Amaranhus [ 14 ], Chenopodium [ 69 ], and Cenchrus [ 70 ], which thrive in disturbed habitats (either altered by natural or anthropogenic forces) due to increased plant fitness through functional and adaptive traits [ 71 ]. The stronger effects of NaCl than of PEG can be explained by the ionic toxicity, as salinity has a toxic component in addition to the increased external osmotic potential that reduces water uptake during imbibition also produced by PEG.…”

“…For this reason, an increasing number of studies are being conducted on responses to drought and salinity not only in model plants, but also in crops and their wild relatives [ 4 , 5 , 6 , 7 , 8 ]. Although unravelling functional responses to environmental factors in invasive plants is gaining interest [ 9 ], analysis of stress tolerance and mechanisms underlying stress responses are scarce in such species [ 10 , 11 , 12 , 13 , 14 , 15 ].…”

Metabolic Profiling Analysis Uncovers the Role of Carbon Nanoparticles in Enhancing the Biological Activities of Amaranth in Optimal Salinity Conditions

“…Salinity induces plant metabolic and molecular changes. A previous study showed that salinity can significantly reduce the rate and final percentages of the germination and emergence of amaranth, resulting in uneven stand establishment and decreased crop yields [33]. A growth reduction was observed in the leaf of amaranth sprouts under saline conditions; such a reduction was associated with a reduction in photosynthetic pigments [34].…”

Growth of Red Amaranth (Amaranthus cruentus L.) Cultivated on Soil-Based Substrate Amended with a Residue of the Black Soldier Fly Larvae Containing Heavy Metals

“…Since the source of the problem was in the growing substrate; then, the first suffering organ was the roots, as indicated by smaller root biomass and shorter roots (Liu et al 2021). The uptake of water and nutrients by affected plants becomes restricted and collectively halts the development of aerial organs, including leaf enlargement (Bellache et al 2022).…”