The interactive effects of salinity and drought stress on germination, seedling growth, and physiological parameters of pumpkin

Abstract

This study aimed to explore the response of pumpkin to salt and drought stress during germination and early plant growth stages. Salt stress was induced with various sodium chloride concentrations (0.00%, 0.25%, 0.50%, and 0.75%) in non-drought (distilled water) and drought (15% PEG-6000) conditions. The seeds of the pumpkin cultivar T28 for snacks were germinated between filter papers using the respective solutions. In the pot experiment, the seedlings at the 2-leaf stage were exposed to these stresses for 30 days. The plant height, fresh weight, dry weight, leaf area, leaf dry matter, chlorophyll content (Chl), relative water content (RWC), and cell membrane stability (CMS) of the plants were inquired. Drought markedly reduced the germination index, plant height, fresh weight, dry weight, leaf area, RWC, and CMS. Conversely, increased mean germination time, Chl, and dry matter were determined in drought conditions. Salinity stress above 0.50% NaCl influenced these traits, with salinity’s inhibitory effects surpassing those of drought. Germination percentage dropped from 100% to 46% at 0.75% NaCl under drought, whereas it remained stable under non-drought stress. Pumpkin was more sensitive to drought and salinity stress at the germination stage than at the early growth stage. The correlation between germination and seedling growth parameters indicated that the germination index and mean germination time were substantially associated with nearly all growth traits of pumpkin. The study highlights the germination index as a key indicator of stress tolerance and identifies 0.50% NaCl as a critical threshold level for pumpkin under salt and drought stress.

Keywords

• Cucurbita pepo L.
• Drought
• Salinity
• Germination
• Plant growth
• Cell membrane stability

References

1. Aghai, A.H., Ehsanzade, P. (2011). Effects of irrigation regime and nitrogen on yield and some physiological parameters in medicinal pumpkin. Journal of Iran Horticultural Science, 42:291-299.
2. Aghbolaghi, M.A., Sedghi, M., Sharifi, R.S., Dedicova, B. (2022). Germination and the biochemical response of pumpkin seeds to different concentrations of humic acid under cadmium stress. Agriculture, 12(3):374. https://doi.org/10.3390/agriculture12030374
3. Aghbolaghi, M.A., Razavi, F. (2021). Improving germination and biochemical aspects in pumpkin (Cucurbita pepo) seeds deterioration under priming by salicylic acid and ascorbic acid. Iranian Journal of Seed Science and Technology, 10:75-88. https://doi.org/10.22092/ijsst.2020.342748.1337
4. Aghbolaghi, M.A., Sedghi, M., Parmoon, G., Dedicova, B. (2023). Pumpkin seeds germination and seedling growth under abiotic stress. In Biological and Abiotic Stress in Cucurbitaceae Crops. IntechOpen. https://doi.org/10.5772/intechopen.1001863
5. Ashraf, F., Zargar, T.B., Veres, S. (2021). Comparison between germinating parameters of basils (Ocimum basilicum L.) and pumpkin (Cucurbita pepo L.) under drought stress conditions. Review on Agriculture and Rural Development, 10(1-2):100-106. https://doi.org/10.14232/rard.2021.1-2.100-106
6. Ashraf, M., Ali, Q. (2008). Relative membrane permeability and activities of some antioxidant enzymes as the key determinants of salt tolerance in canola (Brassica napus L.). Environmental and Experimental Botany, 63(1-3):266-273.
7. Bajji, M., Kinet, J.M., Lutts, S. (2002). The use of the electrolyte leakage method for assessing cell membrane stability as a water stress tolerance test in durum wheat. Plant Growth Regulation, 36:61-70.
8. Cui, Q., Li, Y., He, X., Li, S., Zhong, X., Liu, B., Zhang, D., Li, Q. (2019). Physiological and iTRAQ based proteomics analyses reveal the mechanism of elevated CO2 concentration alleviating drought stress in cucumber (Cucumis sativus L.) seedlings. Plant Physiology and Biochemistry, 143:142-153. https://doi.org/10.1016/j.plaphy.2019.08.025

9. Dziwulska-Hunek, A., Kachel, M., Gagoś, M., Szymanek, M. (2021). Influence of silver nanoparticles, laser light and electromagnetic stimulation of seeds on germination rate and photosynthetic parameters in pumpkin (Cucurbita pepo L.) leaves. Applied Sciences, 11(6):2780. https://doi.org/10.3390/app11062780
10. ElBasyoni, I., Saadalla, M., Baenziger, S., Bockelman, H., Morsy, S. (2017). Cell membrane stability and association mapping for drought and heat tolerance in a worldwide wheat collection. Sustainability, 9(9): 1606. https://doi.org/10.3390/su9091606
11. Elsheery, N.I., Helaly, M.N. Omar, S.A., John, S.V., Zabochnicka-Swiątek, M., Kalaji, H.M., Rastogi, A. (2020). Physiological and molecular mechanisms of salinity tolerance in grafted cucumber. South African Journal of Botany, 130: 90-102.
12. Esan, V.I., Obisesan, I.A., Ogunbode, T.O. (2023). Root system architecture and physiological characteristics of soybean (Glycine max L.) seedlings in response to PEG 6000‐simulated drought stress. International Journal of Agronomy, 9697246. https://doi.org/10.1155/2023/9697246
13. Farooq, S., Azam, F. (2006). The use of cell membrane stability (CMS) technique to screen for salt tolerant wheat varieties. Journal of Plant Physiology, 163(6):629-637.
14. Gülşen, O., Coşkun, G., Demirkaya, M. (2016). Effects of some pretreatments on germination of pumpkin seed. Erciyes Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 32(1):48-53.
15. Horuz, A., Balkaya, A., Yildiz, S., Saribas, S., Uygur, V. (2022). Comparison of the salt stress tolerance of promising Turkish winter squash (Cucurbita maxima Duch.) and pumpkin (Cucurbita moschata Duch.) lines and interspecific hybrids. Gesunde Pflanzen, 74:69-86. https://doi.org/10.1007/s10343-021-00589-9
16. Irik, H.A., Bikmaz, G. (2024). Effect of different salinity on seed germination, growth parameters and biochemical contents of pumpkin (Cucurbita pepo L.) seeds cultivars. Scientific Reports, 14(1):6929. https://doi.org/10.1038/s41598-024-55325-w
17. ISTA (2018). International rules for seed testing. International Seed Testing Association. https://www.seedtest.org/en/
18. Jahed, P., Sedghi, M., Sharifi, R.S., Sofalian, O. (2023). Effect of priming on germination traits and antioxidant enzymes of pumpkin (Cucurbita pepo L.) seeds with different vigor under drought stress. Journal of Agricultural Sciences, 29(2):491-506. https://doi.org/10.15832/ankutbd.1067305
19. Jamil, M., Ashraf, M., Rehman, S., Ahmad, M., Rha, E.S. (2012). Salinity induced changes in cell membrane stability, protein and RNA contents. African Journal of Biotechnology, 11(24):6476-6483.
20. Kaya, G. (2024). Combined effects of drought and low temperature on germination and seedling growth of melon cultivars. Black Sea Journal of Agriculture, 7(2):139-143. https://doi.org/10.47115/bsagriculture.1394747
21. Kulan, E.G., Arpacıoğlu, A., Ergin, N., Kaya, M.D. (2021). Evaluation of germination, emergence and physiological properties of sugar beet cultivars under salinity. Trakya University Journal of Natural Sciences, 22(2): 263-274. https://doi.org/10.23902/trkjnat.947001
22. Kurum, R., Ulukapı, K., Aydınşakir, K., Onus, A.N. (2013). The influence of salinity on seedling growth of some pumpkin varieties used as rootstock. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 41(1):219-225. https://doi.org/10.15835/nbha4118349
23. Kuşvuran, Ş., Kaya, E., Ellialtıoğlu, Ş.Ş. (2021). Role of grafting in tolerance to salt stress in melon (Cucumis melo L.) plants: Ion regulation and antioxidant defense systems. Biotech Studies, 30(1):22-32. https://doi.org/10.38042/biotechstudies.932376
24. Liang, L., Chen, L., Liu, G., Zhang, F., Linhardt, R.J., Sun, B., Li, Q., Zhang, Y. (2022). Optimization of germination and ultrasonic‐assisted extraction for the enhancement of γ‐aminobutyric acid in pumpkin seed. Food Science and Nutrition, 10(6):2101-2110. https://doi.org/10.1002/fsn3.2826
25. Maas, E.V., Grattan, S.R. (1999). Crop yields as affected by salinity. Agricultural Drainage, Agronomy Monographs, 38:55-108. https://doi.org/10.2134/agronmonogr38.c3
26. Maynard, D., Maynard, D.N. (2000). Cucumbers, melons, and watermelons. In: Kiple K.F., Ornelas K.C. (eds) The Cambridge world history of food. Cambridge University Press, Cambridge, UK. pp. 298-313.
27. Michel, B.E., Kaufmann, M.R. (1973). The osmotic potential of polyethylene glycol 6000. Plant Physiology, 51(5):914-916. https://doi.org/10.1104/pp.51.5.914
28. Naeemi, M., Akbari, G.A., Shirani Rad, A.H., Hassanloo, T., Akbari, G.A. (2012). Effect of zeolite application and selenium spraying on water relations traits and antioxidant enzymes in medicinal pumpkin (Cucurbita pepo L.) under water deficit stress conditions. Journal of Crop Improvement, 14:67–81. https://doi.org/10.22059/jci.2012.25045
29. Najafi, S., Nazari Nasi, H., Tuncturk, R., Tuncturk, M., Sayyed, R.Z., Amirnia, R. (2021). Biofertilizer application enhances drought stress tolerance and alters the antioxidant enzymes in medicinal pumpkin (Cucurbita pepo convar. pepo var. Styriaca). Horticulturae, 7(12):588. https://doi.org/10.3390/horticulturae7120588
30. Nijabat, A., Bolton, A., Mahmood-ur-Rehman, M., Shah, A.I., Hussain, R., Naveed, N.H., Ali, A., Simon, P. (2020). Cell membrane stability and relative cell injury in response to heat stress during early and late seedling stages of diverse carrot (Daucus carota L.) germplasm. HortScience, 55(9):1446-1452. https://doi.org/10.21273/HORTSCI15058-20
31. Okçu, G., Kaya, M.D., 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(4):237-242.
32. Oliveira, F.D.A.D., Martins, D.C., Oliveira, M.D., Neta, M.D.S., Ribeiro, M.D.S.D.S., Silva, R.D. (2014). Initial development of pumpkin and squash cultivars submitted to salt stress. Revista Agro@mbiente On-line, 8(2):222-229.
33. Rehman, A., Khalid, M., Weng, J., Li, P., Rahman, S.U., Shah, I.H., Gulzar, S., Tu, S., Ningxiao, F., Niu, Q., Chang, L. (2024). Exploring drought tolerance in melon germplasm through physiochemical and photosynthetic traits. Plant Growth Regulation, 102(3):603-618. https://doi.org/10.1007/s10725-023-01080-3
34. Robinson, R.W., Decker-Walters, D.S. (1997). Cucurbits. CABI., Wallingford, UK. ISNB:0 85199 1335.
35. Saadaoui, W., Tarchoun, N., Msetra, I., Pavli, O., Falleh, H., Ayed, C., Amami, R., Ksouri, R., Petropoulos, S.A. (2023). Effects of drought stress induced by D-Mannitol on the germination and early seedling growth traits, physiological parameters and phytochemicals content of Tunisian squash (Cucurbita maxima Duch.) landraces. Frontiers in Plant Science, 14:1215394. https://doi.org/10.3389/fpls.2023.1215394
36. Salehzade, H., Shishvan, M.I., Ghiyasi, M., Forouzin, F., Siyahjani, A.A. (2009). Effect of seed priming on germination and seedling growth of wheat (Triticum aestivum L.). Research Journal of Biological Sciences, 4(5):629-631.
37. Santos, A.D.S., Sá, F.V.D.S., Souto, L.S., Silva, M.K.D.N., Moreira, R.C., Lima, G.S.D., Silva, L.D.A., Mesquita, E.F.D. (2018). Tolerance of varieties and hybrid of pumpkin and squash to salt stress. Journal of Agricultural Science, 10(1): 38. https://doi.org/10.5539/jas.v10n1p38
38. Sevengör, S., Yasar, F., Kusvuran, S., Ellialtioglu, S. (2011). The effect of salt stress on growth, chlorophyll content, lipid peroxidation and antioxidative enzymes of pumpkin seedling. African Journal of Agricultural Research, 6(21):4920-4924.
39. Seymen, M., Yavuz, D., Dursun, A., Kurtar, E.S., Türkmen, Ö. (2019). Identification of drought-tolerant pumpkin (Cucurbita pepo L.) genotypes associated with certain fruit characteristics, seed yield, and quality. Agricultural Water Management, 221:150-159. https://doi.org/10.1016/j.agwat.2019.05.009
40. Sucre, B., Suárez, N. (2011). Effect of salinity and PEG-induced water stress on water status, gas exchange, solute accumulation, and leaf growth in Ipomoea pes-caprae. Environmental and Experimental Botany, 70(2-3): 192-203. https://doi.org/10.1016/j.envexpbot.2010.09.004
41. Taratima, W., Kunpratum, N., Maneerattanarungroj, P. (2023). Effect of salinity stress on physiological aspects of pumpkin (Cucurbita moschata duchesne.'laikaotok') under hydroponic condition. Asian Journal of Agriculture and Biology, 2023(2):202101050. https://doi.org/10.35495/ajab.2021.01.050
42. Taratima, W., Sudjai, S., Maneerattanarungroj, P. (2022). Growth and anatomical adaptations in response to salinity stress in Cucurbita moschata Duchesne ‘Butternut’(Cucurbitaceae). Sains Malays, 51(5):1317-1324. http://doi.org/10.17576/jsm-2022-5105-04
43. Tarchoun, N., Saadaoui, W., Mezghani, N., Pavli, O. I., Falleh, H., Petropoulos, S.A. (2022). The effects of salt stress on germination, seedling growth and biochemical responses of tunisian squash (Cucurbita maxima Duchesne) germplasm. Plants, 11(6):800. https://doi.org/10.3390/plants11060800
44. Turkmen, O., Uslu, N., Paksoy, M., Seymen, M., Fidan, S., Ozcan, M.M. (2015). Evaluation of fatty acid composition, oil yield and total phenol content of various pumpkin seed genotypes. Rivista Italiana Delle Sostanze Grasse, 92(2): 93–97.
45. Wang, X., Sun, H., Lian, X., Feng, J., Zhao, J., Wang, Y., Liu, Y. (2024). Physiological and biochemical characteristics of cucumber seedlings under different levels of drought stress (PEG 6000 concentrations). Horticultural Science, 51(3):202-11. https://doi.org/10.17221/53/2023-HORTSCI
46. Xu, Y., Guo, S.R., Li, H., Sun, H.Z., Lu, N., Shu, S., Sun, J. (2017). Resistance of cucumber grafting rootstock pumpkin cultivars to chilling and salinity stresses. Horticultural Science and Technology, 35(2):220-231. https://doi.org/10.12972/kjhst.20170025
47. Yasar, F., Uzal, O., Kose, S., Yasar, O., Ellialtioglu, S. (2014). Enzyme activities of certain pumpkin (Cucurbita spp.) species under drought stress. Fresenius Environmental Bulletin, 23(4):1093-1099.