Rayda BEN AYED, Mohsen HANANA, Rekaya AYADI, Lamia HAMROUNI, Nejla LASSOUED, Hichem BEN SALEM, Mohamed LARBI KHOUJA

Multivariate statistical analyses for studying kenaf germination, growth, and fiber production under salinity constraint

It is due to the lack of renewable fiber sources for industrial purposes that the need for finding available and alternativematerial has become imperative. Kenaf (Hibiscus cannabinus L.), a fast-growing industrial crop, would be a potential solution forvalorizing salinized lands and/or soils irrigated with saline water. With the aim of selecting and valorizing salt-tolerant species withhigh fiber yields and industrial values, we launched the assessment of the performance of kenaf culture (var. Guangdong 743-2) undersalinity constraints. Germination and vegetative stages were considered in the present study to better evaluate the whole life cycle ofthe species. Several NaCl concentrations (0, 3, 6, 9, 12, and 15 g $L^{–1}$) were applied to seeds cultivated in petri dishes and to 4-month-oldplants growing in hydroponics. Germination rates (germination capacity and coefficient of velocity), growth characteristics (biomassproduction and relative growth rate), physiological parameters (ionic content and water status), and fiber yields (neutral detergent fiber,acid detergent fiber, and acid detergent lignin) were evaluated to better understand the salt stress and toxic effects on germination,growth, and fiber yield. Multivariate analyses were used to identify the major characteristics pertaining to salinity tolerance. Theobtained results have shown that kenaf variety Guangdong 743-2 is able to germinate and grow under high salinity levels (up to 15g L–1 NaCl), deploying several mechanisms of adaptation. Kenaf could withstand salt stress by germinating smoothly, preserving rootand stem biomass, maintaining relative growth rate, stabilizing root water content, producing new leaves while sacrificing older ones,and behaving as a halophyte species through the inclusion of toxic ions within the aerial part, most probably compartmentalized insidevacuoles to ultimately keep its fiber yields unchanged.

PDF

___

Akubueze EU, Ezeanyanaso CS, Orekoya EO, Akinboade DA, Oni F, Muniru SO, Igwe CC (2014). Kenaf fiber (Hibiscus cannabinus L.): a viable alternative to jute fiber (Corchorus genus) for agrosack production in Nigeria. World J Agric Sci 10: 308-331.
Amira MSAQ (2011). Effect of salt stress on plant growth and metabolism of bean plant Vicia faba (L.). J Saudi Soc Agri Sci 10: 7-15.
Bassil E, Blumwald E (2014). The ins and outs of intracellular ion homeostasis: NHX-type cation/H+ transporters. Curr Opin Plant Biol 22: 1-6.
Belkhir S, Koubaa A, Khadhri A, Ksontini M, Nadji H, Smiti S, Stevanovic T (2013). Seasonal effect on the chemical composition of the leaves of Stipa tenacissima L. and implications for pulp properties. Ind Crops Prod 44: 56-61.
Bewley JD, Black M (1994). Seeds: Physiology of Development and Germination. 2nd ed. New York, NY, USA: Plenum Press.
Carillo P, Annunziata MG, Pontecorvo G, Fuggi A, Woodrow P (2011). Salinity stress and salt tolerance. In: Shanker A, editor. Abiotic Stress in Plants – Mechanisms and Adaptations. Rijeka, Croatia: InTech, pp. 21-38.
CEPI (2003). Etude de positionnement de la branche papier et carton. Confederation of European Paper Industries, Final Report. Tunis, Tunisia: Ministry of Industry and Energy (in French).
Coetzee R, Labuschagne MT, Hugo A (2008). Fatty acid and oil variation in seed from kenaf (Hibiscus cannabinus L.). Ind Crops Prod 27: 104-109.
COM (2013). A New EU Forest Strategy: For Forests and the ForestBased Sector. Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions. Brussels, Belgium: COM.
Curtis PS, Lauchli A (1985). Responses of kenaf to salt stress: germination and vegetative growth. Crop Sci 25: 944-949.
Curtis PS, Lauchli A (1986). The role of leaf area development and photosynthetic capacity in determining growth of kenaf under moderate salt stress. Funct Plant Biol 13: 553-565.
Flowers TJ, Munns R, Colmer TD (2015). Sodium chloride toxicity and the cellular basis of salt tolerance in halophytes. Ann Bot 115: 419-431.
Gupta B, Huang B (2014). Mechanism of salinity tolerance in plants: physiological, biochemical, and molecular characterization. Int J Genomics 2014: e701596.
Hachicha M (2007). Les sols salés et leur mise en valeur en Tunisie. Sécheresse 18: 45-50 (in French).
Hanana M, Cagnac O, Yamaguchi T, Hamdi S, Ghorbel A, Blumwald E (2007). A grape berry (Vitis vinifera L.) cation/proton antiporter is associated with berry ripening. Plant Cell Physiol 48: 804-811.
Hsiao TC, Liu-Kang X (2000). Sensitivity of growth of roots versus leaves to water stress: biophysical analysis and relations to water transport. J Exp Bot 51: 1595-1616.
Hunt R (1990). Basic Growth Analysis: Plant Growth Analysis for Beginners. London, UK: Unwin Hyman.
Jamil A, Riaz S, Ashraf M, Foolad MR (2011). Gene expression profiling of plants under salt stress. Crit Rev Plant Sci 30: 435- 458.
Jha D, Shirley N, Tester M, Roy SJ (2010). Variation in salinity tolerance and shoot sodium accumulation in Arabidopsis ecotypes linked to differences in the natural expression levels of transporters involved in sodium transport. Plant Cell Environ 33: 793-804.
Jin CW, Sun YL, Cho DH (2012). Changes in photosynthetic rate, water potential, and proline content in kenaf seedlings under salt stress. Can J Plant Sci 92: 311-319.
Kotowski F (1962). Temperature relations to germination of vegetable seeds. Proceedings of the American Society of Horticultural Science 23: 176-177.
Memon SA, Hou X, Wang LJ (2010). Morphological analysis of salt stress response of pak choi. Electronic Journal of Environmental, Agricultural and Food Chemistry 9: 248-254.
Monti A, Alexopoulou E (2013). Kenaf: A Multi-Purpose Crop for Several Industrial Applications: New Insights from the Biokenaf Project. Berlin, Germany: Springer Science & Business Media.
Munns R (2002). Comparative physiology of salt and water stress. Plant Cell Environ 25: 239-250.
Nguyen CT, Agorio A, Jossier M, Depré S, Thomine S, Filleur S (2016). Characterization of the chloride channel-like, AtCLCg, involved in chloride tolerance in Arabidopsis thaliana. Plant Cell Physiol 57: 764-775.
Panuccio MR, Jacobsen SE, Akhtar SS, Muscolo A (2014). Effect of saline water on seed germination and early seedling growth of the halophyte quinoa. AoB Plants 6: plu047.
Pessarakli M, Marcum KB, Kopec DM (2001). Growth Responses of Desert Saltgrass under Salt Stress. University of Arizona College of Agriculture 2001 Turfgrass and Ornamental Research Report. Tucson, AZ, USA: University of Arizona.
Reguera M, Bassil E, Blumwald E (2014). Intracellular NHX-type cation/H+ antiporters in plants. Mol Plant 7: 261-263.
Slama I, Abdelly C, Bouchereau A, Flowers T, Savouré A (2015). Diversity, distribution and roles of osmoprotective compounds accumulated in halophytes under abiotic stress. Ann Bot 115: 433-447.
Sleimi N (2002). Mécanismes d’adaptation à la salinité et comportement sur eau de deux halophytes fourragères : Suaeda fruticosa et Spartina altrniflora. PhD, Université Tunis-2, Tunis, Tunisia (in French).
Sokal RR, Rohlf, FJ (1995). Biometry: The Principles and Practice of Statistics in Biological Research. 3rd ed. New York, NY, USA: W.H. Freeman and Co.
Taffouo VD, Kouamou JK, Ngalangue LMT, Ndjeudji BAN, Akoa A (2009). Effects of salinity stress on growth, ions partitioning and yield of some cowpea (Vigna ungiuculata L. Walp) cultivars. Int J Bot 5: 135-143.
Van Soest PJ, Robertson JB, Lewis BA (1991). Methods for dietary fiber, neutral detergent fiber, and non-starch carbohydrates in relation to animal nutrition. J Dairy Sci 74: 3583-3597.
Villar JC, Revilla E, Gómez N, Carbajo JM, Simón JL (2009). Improving the use of kenaf for kraft pulping by using mixtures of bast and core fibers. Ind Crops Prod 29: 301-307.