Muhammad Zaheer AHMED, Farhat AGHA, Bilquees GUL, Muhammad Ajmal KHAN

Interactive effects of salinity and plant density on the growth of Cyperus arenarius, a sand dune stabilizer

Competition and environmental stress are crucial factors for structuring plant population in natural habitats. Cyperus arenarius, a sedge of coastal sand dunes habitat, is a suitable species for coastal restoration and dune stabilization, but how salinity and plant density interact in affecting its growth is still unknown. Here, growth, survival, and physiological responses of C. arenarius to salinity (sea-salt) and plant density were investigated. A set of growth experiments in which combinations of 4 salinity levels (0, 2, 4, and 6 $S m{–1}$ sea-salt) and 3 planting densities (2, 5, 8 plants pot–1) were tested under controlled greenhouse conditions. Plant biomass and height were optimal in 2 $S m{–1}$ sea-salt while biomass decreased considerably at 6 S $S m{–1}$. The inhibitory effect of high salinity was more severe in shoot dry mass relative to that of root dry mass, which resulted in increasing root/shoot dry mass ratio. Tissue succulence declined while the accumulation of Na and Cl increased with the increment of salinity, especially in root. Plant nutrient $(K^{+}, Ca^{2+}, and Mg^{2+})$ contents decreased under salinity. Plant height was more sensitive with increasing plant density than biomass. High plant density (8 plants $pot^{–1})$ lowered tissue biomass and water content in non-saline conditions to the similar levels observed under the 6 S $S m{–1}$ seasalt salinity. Moreover, the combined effect of high salinity and increasing plant density had highly negative effects on plant growth attributes and water relations than their individual effect.

PDF

___

Adnan MY, Hussain T, Ahmed MZ, Gul B, Khan MA (2021). Growth regulation of Desmostachya bipinnata by organ-specific biomass, water relations, and ion allocation responses to improve salt resistance. Acta Physiologia Plantarum 43: 1–12.
Alessio GA, De Lillis M, Brugnoli E, Lauteri M (2004). Water sources and water-use efficiency in Mediterranean coastal dune vegetation. Plant Biology 6: 350-357. doi: 10.1055/s-2004-820882
Delf EM (1912). Transpiration in succulent plants. Annals of Botany 26: 409–442. doi.org/10.1093/oxfordjournals.aob.a089398
Feizbakhsh A, Aghassi A, Naeemy A (2012). Chemical constituents of the essential oils of Cyperusdifformis L. and Cyperusarenarius Retz from Iran, Journal of Essential Oil Bearing Plants, 15:1, 48-52. doi: 10.1080/0972060X.2012.10644018
Flowers TJ, Munns R, Colmer TD (2015). Sodium chloride toxicity and the cellular basis of salt tolerance in halophytes. Annals of Botany 115: 419-431. doi: 10.1093/aob/mcu217
Glenn EP (1987). Relationship between cation accumulation and water content of salt-tolerant grasses and a sedge. Plant Cell Environment 10: 205–212. doi:10.1111/1365-3040.ep11602236
Glenn EP, Nagler PL (2005). Comparative ecophysiology of Tamarix ramosissima and native trees in western U.S. riparian zones. Journal of Arid Environment 61: 419–446. doi.org/10.1016/j. jaridenv.2004.09.025
Gulzar S, Khan MA, Ungar IA (2003). Salt tolerance of a coastal salt marsh grass. Communications in Soil Science and Plant Analysis 34: 2595–2605. doi.org/10.1081/CSS-120024787
Khan MA, Ungar IA (1999). Seed germination and recovery of Triglochin maritima from salt stress under different thermoperiods. Great Basin Naturalist 59: 144–150.
Koyro HW, Geissler N, Hussain S, Huchzermeyer B (2005). Mechanisms of cash crop halophytes to maintain yields and reclaim soils in arid areas. In: Khan MA, Weber DJ, editors. Ecophysiology of high salinity tolerant plants, Netherlands: Springer Publication, pp. 345-366.
Kukumen I (2001). Cyperaceae. In: Ali SI, Qaiser M, editors. Flora of Pakistan. University of Karachi and Missouri Botanical Garden, pp. 277.
Maathuis FJ, Ahmad I, Patishtan J (2014). Regulation of Na+ fluxes in plants. Frontiers in Plant Science 5: 467. doi:10.3389/ fpls.2014.00467
Marcum KB (2002). Growth and physiological adaptations of grasses to salinity stress. In: Pessarakli M, editor. Handbook of plant and crop physiology. 2nd ed. New York: Marcel Dekker, pp. 623–635.
Popp M, Polania J (1989). Compatible solutes in different organs of mangrove trees. Annals of Forest Science 46: 842–844. doi:10.1051/forest:198905ART0185
Shabala S, Shabala S, Cuin TA, Pang J, Percey W et al. (2010). Xylem ionic relations and salinity tolerance in barley. The Plant Journal 61: 839-853. doi:10.1111/j.1365-313X.2009.04110.x
Shoukat E, Ahmed MZ, Abideen Z, Azeem M, Ibrahim M et al. (2020). Short and long term salinity induced differences in growth and tissue specific ion regulation of Phragmites karka. Flora 263: Article 151550. doi:10.1016/j.flora.2020.151550
SPSS Amos (version 16). (2007). Armonk, NY: IBM.
Sun JM, Wang J, Ding MQ, Deng SR, Liu MQ et al. (2010). H2O2 and cytosolic $Ca2^{+}$ signals triggered by the PM H+-coupled transport system mediate $K^{+}/Na^{+}$ homeostasis in NaCl stressed Populus euphratica cells. Plant Cell Environment 33: 943-958.
Uddin M, Juraimi AS, Ismail M, Hossain M, Othman R et al. (2012). Physiological and growth responses of six turfgrass species relative to salinity tolerance. The Scientific World Journal. doi:10.1100/2012/905468
Ungar IA (1992). The effect of intraspecific competition on growth reproduction and survival of the halophyte Spergularia marina. International Journal of Plant Sciences 153: 421–424. doi:10.1086/297047
USACE (U.S. Army Corps of Engineers) (2013). Hurricane sandy coastal projects performance evaluation study: disaster relief appropriations act. Washington, DC: U.S. Army Corps of Engineers.
Vogel AI, Jeffery GH. 1989. Vogel’s textbook of quantitative chemical analysis. Wiley.
Wang LW, Showalter AM, Ungar IA (2005). Effects of intraspecific competition on growth and photosynthesis of Atriplex prostrata. Aquatic Botany 83: 187-192. doi:10.1016/j. aquabot.2005.06.005
Wang Q, Jiang L, Chen Y, Tian X, Lv G (2021). Abiotic stressby-competition interactions drive hormone and nutrient changes to regulate Suaeda salsa growth. Global Ecology and Conservation, p.e01845.
Wege S, Gilliham M, Henderson SW (2017). Chloride: not simply a ‘cheap osmoticum’, but a beneficial plant macronutrient. Journal of Experimental Botany 68: 3057-3069.
Wu L, Lin H (1994). Salt tolerance and salt uptake in diploid and polyploid buffalo grasses (Buchloe dactyloides). Journal of Plant Nutrition 17: 1905-1928. doi.org/10.1080/01904169409364854
Yu H, Shen N, Yu D, Liu C (2019). Effects of temporal heterogeneity of water supply and spatial heterogeneity of soil nutrients on the growth and intraspecific competition of Bolboschoenus yagara depend on plant density. Frontiers in Plant Science 9: 1987. doi: 10.3389/fpls.2018.01987
Zhang R, Tielbörger K (2020). Density-dependence tips the change of plant–plant interactions under environmental stress. Nature Communications 11: 1-9. doi:10.1038/s41467-020-16286-6