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

Abstract

Erigeron bonariensis and E. sumatrensis are two noxious weeds present in many parts of the world. Their tolerance to salinity and water deficit was analysed at the seed germination stage and during vegetative development. Seed germination was tested in solutions with different concentrations of NaCl and polyethylene glycol (PEG). Growth parameters, photosynthetic pigments, ion accumulation, and antioxidant mechanisms were analysed in plants that were subjected to increasing NaCl solutions, or severe water deficit by completely restricting irrigation. Seed germination was mostly affected by NaCl, but less by PEG in both species. E. bonariensis had a faster germination in all treatments and maintained a higher percentage of germination under the highest concentration of salt applied. Growth responses were similar in the two species, both being more affected by higher salt concentrations than by water deficit. The main differences in the responses of the two species to stress regard K+ and proline concentration. K+ in roots decreased under salt stress in E. sumatrensis, but remained constant in leaves, whereas in E. bonariensis increased in roots and leaves in salt-stressed plants. Proline concentration increased in all E. bonariensis plants under salt stress, but only in those under the highest salt concentration in E. sumatrensis. The results obtained indicate that the two species are relatively tolerant to water deficit and medium salinity but are susceptible to high NaCl concentrations.

Seed Germination and Plant Growth under Drought Stress of Herbicide-Resistant and Herbicide-Susceptible Biotypes of Conyza Species and Smart Farming Approaches

“…The seeds of the two species germinated at a different rate, with C. sumatrensis being the faster one. The highest percentage of seed germination for C. sumatrensis was absolutely comparable to the one mentioned by Bellache et al [10]. Under low drought stress (−0.2 MPa), the resistant biotype of C. sumatrensis had significantly higher germination percentage than the susceptible biotype.…”

“…On the contrary, many weeds also show such ability, allowing us even to predict future shifts of specific species, dispersal of invasive species and changes in weed communities [9]. This is also the case for Conyza (Erigeron) species, since they are very often exposed to severe drought and other extreme environmental conditions and consequently any plasticity and adaptation would be beneficial for them [10].…”

Irrigation Practice in Cultivation of Stevia rebaudiana Bertoni in Cooler Climates—Case Study in Poland

“…The major phenolic compounds found in the stevia leaves are hydroxycinnamic acid and quinic acid, characterised with valuable therapeutic properties [3]. General studies about a variety of different plants, mostly from the Asteraceae family, have shown that increases in the production of various phenolic compounds is a typical response of many of the plant species to drought stress; therefore, it is not surprising to see these results in the studies about Stevia rebaudiana plants [31][32][33].…”

Responses of different invasive and non-invasive ornamental plants to water stress during seed germination and vegetative growth

“…Another trait of invasive plants is their increased phenotypic plasticity, which generally gives them a greater fitness advantage 8 . The significance of climate change's effects on biological invasions is reflected in an increasing number of studies on invasive species' responses to abiotic stress under different experimental conditions 9 – 11 and comparative studies of functional traits in invasive and native species 2 , 12 , 13 . However, a binary classification into invasive and non-invasive ornamentals is problematic since invasiveness is not discrete, and species can be native to one place but invasive to another 14 .…”