Effects of water stress and NaCl stress on different life cycle stages of the cold desert annual Lachnoloma lehmannii in China

Abstract

For a plant species to complete its life cycle in arid and saline environments, each stage of the life cycle must be tolerant to the harsh environmental conditions. The aim of the study was to determine the effects of water stress (water potentials of-0.05,-0.16,-0.33,-0.56,-0.85 and-1.21 MPa) and NaCl stress (50, 100, 200, 300, 400, 500 and 600 mmol/L NaCl) on seed germination percentage, seedling survival and growth, juvenile growth and plant reproduction of Lachnoloma lehmannii Bunge (Brassicaceae), an cold desert annual that grows in the Junggar Basin of Xinjiang, China in 2010. Results indicated that low water stress (-0.05 and-0.16 MPa) had no significant effect on seed germination percentage. With a decrease in water potential, germination percentage decreased, and no seeds germinated at-0.85 and-1.21 MPa water stresses. Germination percentage of seeds was significantly affected by NaCl stress, and higher germination percentages were observed under non-saline than saline conditions. An increase in NaCl concentrations progressively inhibited seed germination percentage, and no seeds germinated at ≥400 mmol/L NaCl concentration. Non-germinated seeds were transferred from both PEG (polyethylene glycol-6000) and NaCl solutions to distilled water for seed germination recovery. The number of surviving seedlings and their heights and root lengths significantly decreased as NaCl stress increased. About 30% of the plants survived and produced fruits/seeds at 200 mmol/L NaCl concentration. Thus, seed germination, seedling establishment and reproductive stage in the life cycle of L. lehmannii are water-and salt-tolerant, with seedlings being the least tolerant. These tolerances help explain why this species can survive and produce seeds in arid and saline habitats.

The technology of improving almond planting material tolerance to the salt stresses of soils based on experience in phytotron

“…They showed the higher adaptation to the salt stress in germination period and ability to tolerate it after field setting. It corresponds on the whole to the earlier obtained results for other cultures [12].…”

Involvement of cell cycle and ion transferring in the salt stress responses of alfalfa varieties at different development stages

“…At young seedling stage, both 100 and 150 mM NaCl generated cell death and membrane damage in ZM1 and D4V, divergent from the inducing effect of 100 mM NaCl on D4V primary root growth. This result supported prior findings that plants at the immature seedling stage were more susceptible to salt stress [ 45 , 46 ]. Remarkably, young seedlings of ZM1 were more salt-tolerant than D4V, exhibiting milder cell death, growth retardation, membrane peroxidation and chlorophyll degradation (Figs.…”

Variations in root architecture traits and their association with organ mass fraction of common annual ephemeral species in the desert of northern Xinjiang

“…The most published research have focused on the adaptive characteristics of the aboveground parts of annual ephemerals (Cheng & Tan, 2009 ; Lu et al., 2015 ; Mamut et al., 2018 ; Xiao et al., 2014 ), with relatively few studies on root systems. In addition, published empirical experiments mainly focus on the impact of environmental factors on the growth and biomass allocation patterns of annual ephemerals (Cheng et al., 2006 ; Mamut et al., 2019 ; Qiu et al., 2007 ; Zhang et al., 2020 ), with little attention paid to the ecological adaptation of root system architecture of annual ephemerals to the desert environment in the genetic context.…”