Genotypic differences in plant growth responses and ion accumulations to salt stress conditions of sweet gourd ( Cucurbita moschata) Rahima Khatoon Plant Physiology Section, Horticulture Research Center, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur, Bangladesh Md. Mokter Hossain* Department of Horticulture, Faculty of Agriculture, Bangladesh Agricultural University, Mymensingh - 2202, Bangladesh M. A. Rahim Department of Horticulture, Faculty of Agriculture, Bangladesh Agricultural University, Mymensingh - 2202, Bangladesh Md. Habibur Rahman Department of Horticulture, Faculty of Agriculture, Bangladesh Agricultural University, Mymensingh - 2202, Bangladesh Limu Akter Vegetable Division, Horticulture Research Center, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur, Bangladesh *Corresponding author. Email: mokter.agr@bau.edu.bd Article Info https://doi.org/10.31018/ jans.v14i2.3386 Received: March 12, 2022 Revised: May 11, 2022 Accepted: May 18, 2022 This work is licensed under Attribution-Non Commercial 4.0 International (CC BY-NC 4.0). © : Author (s). Publishing rights @ ANSF. ISSN : 0974-9411 (Print), 2231-5209 (Online) journals.ansfoundation.org Research Article INTRODUCTION Salinity is one of the most important abiotic factors that cause a reduction in the growth, development and yield of many crops. Salinity negatively affects plant growth when salts accumulate in the root zone. High levels of salinity affect seed germination plant growth by water deficit (osmotic stress), ion imbalance and ion toxicity (ionic stress) or a combination of these factors (Lauchli and Grattan, 2007). Plant species can differ markedly in their responses to salt tolerance (Dasgan and Koc, 2009; Kusuvuran et al., 2011). Salt toxicity primarily occurs in the older leaves, where Na and Cl build up in the leaves over a long period of time. The cultivable areas in coastal districts are affected with varying de- grees of salinity 3.63-27.67 dS/m (Akter et al., 2008). In Bangladesh, about 3 million hectares of land are affect- ed by salinity, mainly in the coastal and south-eastern Abstract The sweet gourd (Cucurbita moschata Duch ex Poir) is a rich source of vitamins and minerals, especially high carotenoids. Due to climate change and intensive water use, soil salinization is increasing day by day. Salt stress decreases the growth and qual- ity of many crops. Thus, the objective of the present study was to monitor the growth and ion accumulation of fourteen sweet gourd inbred. The study was conducted in 2018 with 14 sweet gourd inbreds (P 1 , P 2 , P 3 , P 4 , P 5 , P 6 , P 7 , P 8 , P 9 , P 10 , P 11 , P 12 , P 13 and P 14 ) and to identify superior genotypes. Electrical conductivity (EC) based salt was applied at 4, 8, 12 and 16 dS/m NaCl salinity levels for all inbred. Tap water was used as a control. Treatments were imposed at the four to five -leaf stage. Salt stress resulted in significantly decreased growth and essential ion in sweet gourd inbred. Vine length (P 11 =164.9 to149.5cm, control to 16 dS/m), the number of leaves (P11=31 to 24.33, control to 16 dS/m), internode length (P 12 =9.67 to 9.83cm, control to 16 dS/ m), stem girth (16.38 to 15.87mm, control to 16 dS/m) and K + ion accumulations were decreased (P 6 =2.09 to 1.44, control to 16 dS/m) compared to the control. But Na + ion was increased (P 13 =0.17 to 1.25, control to 16 dS/m) in all inbred under salt condi- tions. Sweet gourd inbred showed wide variation in their response to salt tolerance. However, six sweet gourd inbred (P 6 , P 8 , P 9 , P 11 , P 12 and P 14 ) were found as promising as salt-tolerant in respect of growth and ion accumulation. These selected promis- ing salt-tolerant sweet gourd genotypes will be used for breeding programmes to develop high yielding varieties for better pro- duction in the near future in saline areas of Bangladesh. Keywords: Growth, Inbred, Ion accumulation, Salinity, Sweet gourd, Tolerant How to Cite Khatoon, R. et al. (2022). Genotypic differences in plant growth responses and ion accumulations to salt stress conditions of sweet gourd (Cucurbita moschata). Journal of Applied and Natural Science, 14(2), 373 - 384. https://doi.org/10.31018/jans.v14i2.3386