Abstract
The aim of the present study was to establish an experimental system in controlled conditions to study the physiological effect of abiotic/biotic interaction using a rare wild leguminous plant species from coastal sand dunes, Anthyllis maritima. The particular hypothesis tested was that there is an interaction between sand burial, rhizobial symbiosis and salt treatment at the level of physiological responses. Experiment in controlled conditions included 18 treatment combinations of experimental factors, with two intensities of sand burial, rhizobial inoculation and two types of NaCl treatment (soil irrigation and foliar spray). Shoot biomass was significantly affected both by burial and by inoculation, and by interaction between burial and NaCl in the case of shoot dry mass. For plants sprayed with NaCl, burial had a strong significant positive effect on shoot growth irrespective of inoculation. General effect of inoculation with rhizobia on shoot growth of plants without NaCl treatment was negative except for the plants buried 2 cm with sand, where significant stimulation of shoot dry mass by inoculant was found. The positive effect of burial on shoot growth was mainly associated with an increase in leaf petiole height and number of leaves. Performance index significantly increased in buried plants in all treatment combinations, and leaf chlorophyll concentration increased in buried plants independently on burial depth, and only in plants not treated with NaCl. Inoculation led to significant increase of leaf peroxidase activity in all treatment combinations except NaCl-irrigated plants buried for 2 cm by sand. Sand burial stimulated peroxidase activity, mostly in non-inoculated plants, as inoculation itself led to increased enzyme activity. In conclusion, strong interaction between sand burial and NaCl treatment was evident, as the latter significantly affected the effect of burial on growth and physiological indices. Moreover, rhizobial symbiosis had a significant effect on physiological processes through interaction with both sand burial and NaCl treatment, but the effect was rather controversial; it was positive for photosynthesis-related parameters but negative for growth and tissue integrity indices.
Highlights
Environmental factors in coastal habitats form specific conditions requiring particular morphological and physiological adaptations of coastal plants, which is one of the reasons why many rare plant species are found there [1,2]
Results of Analysis of variance (ANOVA) showed that leaf chlorophyll concentration and performance index were highly significantly affected by burial, inoculant and time, but not by NaCl (Table 4)
To evaluate the effects of sand burial, nitrogen-fixing rhizobial symbiosis and salt treatment, as well as their interactions on Anthyllis maritima plants from coastal sand dunes, morphological parameters were used as primary evidence for changes in growth
Summary
Environmental factors in coastal habitats form specific conditions requiring particular morphological and physiological adaptations of coastal plants, which is one of the reasons why many rare plant species are found there [1,2]. In coastal areas where sand dunes are formed, plant burial by sand represents the main specific environmental factor affecting growth and physiological performance of plants [3], leading to specific vegetation zonation patterns [4]. The importance of symbiotic N2-fixing relationships for wild legume species has been studies mostly in respect to mineral nutrition, but information is available on how rhizobial symbiosis affects responses of leguminous plants to unfavourable environmental conditions, as in arid [10] or saline [11,12] regions. There is no data available on the effects of rhizobial symbiosis based on studies with wild plants from coastal dune habitats
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
