The Effect of Different Water Potentials on Seed Germination and Growth of some Persian Walnut Populations

Document Type : Research Article


1 Department of Soil Science, Faculty of Agriculture, University of Jiroft, Jiroft, Iran

2 Department of Soil Science, Faculty of Agriculture, Shahid Bahonar University of Kerman, Kerman, Iran

3 Department of Horticultural Science, Faculty of Agriculture, University of Jiroft, Jiroft, Iran


In this study, seven walnut populations (Rabor, Hanza, Sardoueih, Dalfard, Bidkhan, Dehbakri, and Baft) were selected from Kerman province and compared for drought stress tolerance. Water potential between 0 and -1.5 MPa was obtained by polyethylene glycol 6000 solutions. Germination percentage, leaf relative water content (LRWC), and growth parameter of seedlings diminished with increasing drought stress, but it varied across the genotypes. The Dehbakri genotype was the most tolerant to osmotic stress. In contrast, Dalfard and Bidkhan were the most sensitive to osmotic stress in which no germination occurred at -1.5 MPa. Additionally, drought treatment increased proline and soluble sugar content in the shoot and root in the tolerant genotypes. These results suggest that the accumulated proline and soluble sugar promote drought stress. Overall, the concentration of phosphorus, potassium, calcium, magnesium, and manganese increased with a reduction in the water potential while nitrogen, copper, zinc, and iron elements dropped with the decrease in water potential. Using cluster analysis, Dehbakri was classified as the most tolerant genotype. Baft, Sardoueih, Rabor, and Hanza were semi-sensitive genotypes; finally Dalfard and Bidkhan were classified as the most sensitive genotypes. For future production of drought tolerant rootstock, Dehbakri genotype is suggested to be used in breeding programs.


Arab MM, Marrano A, Abdollahi-Arpanahi R, Leslie CA, Askari H, Neale DB, Vahdati K (2019) Genome-wide patterns of population structure and association mapping of nut-related traits in Persian walnut populations from Iran using the Axiom J. regia 700K SNP array. Scientific Reports. 9(1), 6376.
Bates L, Waldren R, Teare I (1973) Rapid determination of free proline for water-stress studies. Plant Soil. 39, 205-207.
Behrooz A, Vahdati K, Rejali F, Lotfi M, Sarikhani S, Leslie C (2019) Arbuscular Mycorrhiza and Plant Growth-promoting Bacteria Alleviate Drought Stress in Walnut. HortScience. 54, 1087-1092.
Bremner JM, Mulvaney C (1982) Nitrogen—total. Methods of soil analysis Part 2 Chemical and microbiological properties. 595-624.
Chaves M, Oliveira M (2004) Mechanisms underlying plant resilience to water deficits: prospects for water-saving agriculture. Journal of Experimental Botany. 55, 2365-2384.
Close DC, Wilson SJ (2002) Provenance effects on pre-germination treatments for Eucalyptus regnans and E. delegatensis seed. Forest Ecology and Management. 170, 299-305.
da Silva EC, Nogueira R, da Silva MA, de Albuquerque MB (2011) Drought stress and plant nutrition. Plant Stress. 5, 32-41.
Dubois M, Gilles KA, Hamilton JK, Rebers P, Smith F (1956) Colorimetric method for determination of sugars and related substances. Analytical Chemistry. 28, 350-356.
Esmaeilpour A, Van Labeke MC, Samson R, Boeckx P, Van Damme P (2016) Variation in biochemical characteristics, water status, stomata features, leaf carbon isotope composition and its relationship to water use efficiency in pistachio (Pistacia vera L.) cultivars under drought stress condition. Scientia Horticulturae. 211, 158-166.
Farooq M, Wahid A, Kobayashi N, Fujita D, Basra S (2009) Plant drought stress: effects, mechanisms and management.  Sustainable Agriculture. Springer. 153-188.
Fulton A, Buchner R (2006) The effect of water stress on walnut trees growth, productivity and economics, UC Farm Advisors Draft Publication, Tehama County. University of California, Davis, CA.
García‐Sánchez F, Syvertsen J, Gimeno V, Botía P, Perez‐Perez JG (2007) Responses to flooding and drought stress by two citrus rootstock seedlings with different water‐use efficiency. Physiologiae Plantarum. 130, 532-542.
Gigon A, Matos AR, Laffray D, Zuily-Fodil Y, Pham-Thi AT (2004) Effect of drought stress on lipid metabolism in the leaves of Arabidopsis thaliana (ecotype Columbia). Annals of Botany. 94, 345-351.
Hare P, Cress W, Van Staden J (1997) The involvement of cytokinins in plant responses to environmental stress. Plant Growth Regulation. 23, 79-103.
Harris D, Tripathi R, Joshi A (2002) On-farm seed priming to improve crop establishment and yield in dry direct-seeded rice. Direct seeding: Research Strategies and Opportunities, International Research Institute, Manila, Philippines.  231-240.
Hartmann H, Kester D, Geneve R, Davies F (2001) Plant propagation principles and practices. Prentice Hall, Engle wood Cliffs, NJ. 83.
Hoque MA, Banu MNA, Nakamura Y, Shimoishi Y, Murata Y (2008) Proline and glycinebetaine enhance antioxidant defense and methylglyoxal detoxification systems and reduce NaCl-induced damage in cultured tobacco cells. Journal of Plant Physiology. 165, 813-824.
Irigoyen J, Einerich D, Sánchez‐Díaz M (1992) Water stress induced changes in concentrations of proline and total soluble sugars in nodulated alfalfa (Medicago sativd) plants. Physiologiae Plantarum.. 84, 55-60.
Islam MM, Hoque MA, Okuma E, Banu MNA, Shimoishi Y, Nakamura Y, Murata Y (2009) Exogenous proline and glycinebetaine increase antioxidant enzyme activities and confer tolerance to cadmium stress in cultured tobacco cells. Journal of Plant Physiology. 166, 1587-1597.
Karimi S, Karami H, Mokhtassi-Bidgoli A, Tavallali V, Vahdati K (2018) Inducing drought tolerance in greenhouse grown Juglans regia by imposing controlled salt stress: The role of osmotic adjustment. Scientia Horticulturae. 239, 181-192.
Kaya MD, Okçu G, Atak M, Çıkılı Y, Kolsarıcı Ö (2006) Seed treatments to overcome salt and drought stress during germination in sunflower (Helianthus annuus L.). European Journal of Agronomy. 24, 291-295.
Kishor PK, Sangam S, Amrutha R, Laxmi PS, Naidu K, Rao K, Rao S, Reddy K, Theriappan P, Sreenivasulu N (2005) Regulation of proline biosynthesis, degradation, uptake and transport in higher plants: its implications in plant growth and abiotic stress tolerance. Current Science. 88, 424-438.
Liu C, Liu Y, Guo K, Fan D, Li G, Zheng Y, Yu L, Yang R (2011) Effect of drought on pigments, osmotic adjustment and antioxidant enzymes in six woody plant species in karst habitats of southwestern China. Environmental and Experimental Botany. 71, 174-183.
Lotfi N, Vahdati K, Kholdebarin B, Amiri R (2010a) Soluble sugars and proline accumulation play a role as effective indices for drought tolerance screening in Persian walnut (Juglans regia L.) during germination. Fruits. 65, 97-112.
Mengel K, Kirkby EA, Kosegarten H, Appel T (2001) Nitrogen.  Principles of plant nutrition. Springer. 397-434.
Michel BE, Kaufmann MR (1973) The osmotic potential of polyethylene glycol 6000. Plant Physiology. 51, 914-916.
Mishra S, Dubey RS (2006) Inhibition of ribonuclease and protease activities in arsenic exposed rice seedlings: role of proline as enzyme protectant. Journal of Plant Physiology. 163, 927-936.
Murillo‐Amador B, López‐Aguilar R, Kaya C, Larrinaga‐Mayoral J, Flores‐Hernández A (2002) Comparative effects of NaCl and polyethylene glycol on germination, emergence and seedling growth of cowpea. Journal of Agronomy and Crop Science. 188, 235-247.
Negash L (2003) Vegetative propagation of the threatened African wild olive [(Olea europaea L.) subsp. cuspidata (Wall. ex DC.) Ciffieri]. New Forests. 26, 137-146.
Okçu G, Kaya MD, Atak M (2005) Effects of salt and drought stresses on germination and seedling growth of pea (Pisum sativum L.). Turkish Journal of Agriculture and Forestry. 29, 237-242.
Ranney TG, Bassuk NL, Whitlow TH (1991) Osmotic adjustment and solute constituents in leaves and roots of water-stressed cherry (Prunus) trees. Journal of the American Society for Horticultural Science. 116, 684-688.
Schultz HR, Matthews MA (1993) Xylem development and hydraulic conductance in sun and shade shoots of grapevine (Vitis vinifera L.): evidence that low light uncouples water transport capacity from leaf area. Planta. 190, 393-406.
Shamim F, Johnson GN, NAQVI SS, Waheed A (2013) Higher antioxidant capacity protects photosynthetic activities as revealed by Chl a fluorescence in drought tolerant tomato genotypes. Pakistan Journal of Botany. 45, 1631-1642.
Sharma P, Dubey RS (2005) Modulation of nitrate reductase activity in rice seedlings under aluminium toxicity and water stress: role of osmolytes as enzyme protectant. Journal of Plant Physiology. 162, 854-864.
Sofo A, Dichio B, Xiloyannis C, Masia A (2004) Lipoxygenase activity and proline accumulation in leaves and roots of olive trees in response to drought stress. Physiolae Plantarum. 121, 58-65.
Szabados L, Savouré A (2010) Proline: a multifunctional amino acid. Trends in Plant Science. 15, 89-97
Székely G, Ábrahám E, Cséplő Á, Rigó G, Zsigmond L, Csiszár J, Ayaydin F, Strizhov N, Jásik J, Schmelzer E (2008) Duplicated P5CS genes of Arabidopsis play distinct roles in stress regulation and developmental control of proline biosynthesis. The Plant Journal. 53, 11-28.
Thomas GW (1982) Exchangeable Cations. Methods of Soil Analysis. Part 2. Chemical and Microbiological Properties. 2nd Edition. Agronomy. 9, 159-165.
Vahdati K, Lotfi N, Kholdebarin B, Hassani D, Amiri R, Mozaffari MR, Leslie C (2009) Screening for Drought-tolerant Genotypes of Persian Walnuts (Juglans regia L.) During Seed Germination. HortScience. 44, 1815-1819.
Vahdati K, Pourtaklu SM, Karimi R, Barzehkar R, Amiri R, Mozaffari M, Woeste K (2015) Genetic diversity and gene flow of some Persian walnut populations in southeast of Iran revealed by SSR markers. Plant Systematic and Evoluation. 301, 691-699.
Wang Z, Quebedeaux B, Stutte G (1995) Osmotic adjustment: effect of water stress on carbohydrates in leaves, stems and roots of apple. Functional Plant Biology. 22, 747-754.
Yakushiji H, Morinaga K, Nonami H (1998) Sugar accumulation and partitioning in Satsuma mandarin tree tissues and fruit in response to drought stress. Journal of the American Society for Horticultural Science. 123, 719-726.
Zaher-Ara T, Boroomand N, Sadat-Hosseini M (2016) Physiological and morphological response to drought stress in seedlings of ten citrus. Trees. 30, 985-993.
Zeid I, Shedeed Z (2006) Response of alfalfa to putrescine treatment under drought stress. Biologiae Plantarum. 50, 635-640.
Zhang WW, Yang HQ, You SZ, Ran K (2015) MhNCED3 in Malus hupehensis Rehd. induces NO generation under osmotic stress by regulating ABA accumulation. Plant Physiology and Biochemistry. 96, 254-260.
Zhu J, Kang H, Tan H, Xu M (2006) Effects of drought stresses induced by polyethylene glycol on germination of Pinus sylvestris var. mongolica seeds from natural and plantation forests on sandy land. Journal of Forest Research. 11, 319-328.