Genotypic differences in plant growth responses and ion accumulations to salt stress conditions of sweet gourd (Cucurbita moschata)

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 quality 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 (P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13 and P14) 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 (P11=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 (P12=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 (P6=2.09 to 1.44, control to 16 dS/m) compared to the control. But Na+ ion was increased (P13=0.17 to 1.25, control to 16 dS/m) in all inbred under salt conditions. Sweet gourd inbred showed wide variation in their response to salt tolerance. However, six sweet gourd inbred (P6, P8, P9, P11, P12 and P14) were found as promising as salt-tolerant in respect of growth and ion accumulation. These selected promising salt-tolerant sweet gourd genotypes will be used for breeding programmes to develop high yielding varieties for better production in the near future in saline areas of Bangladesh.