Effect of Salt Stress (NaCl) on Seed Germination and Vegetative Growth of Hollyhock (Althaea rosea L.)

Salinity is alarming issue to crop production worldwide. Evaluation of crop plants at early growth stages is perquisite to determine tolerance of plants to salt stress. The pot experiment was performed during 2019 to analyze the impact of salt stress (NaCl) on germination and growth attributes of hollyhock (Althaea rosea L.) genotypes. The trial was set up at the nursery of Sindh Agriculture University Tandojam employing completely randomized design (factorial). The seed germination and vegetative growth was evaluated in two genotypes of hollyhock that included Halo Blush and Scarlet Eye. The treatments included S1 = Canal irrigation water (Control), S2 =3.0 dS m-1, S3 =6.0 dS m-1, S4 = 9.0 dS m-1 and S5 = 12.0 dS m-1. The germination and growth of plants were substantially affected by salinity levels. The seeds sown by applying canal water produced vigorous plants with higher germination. Moreover, plants irrigated with canal water revealed maximum foliage production with better shoot and root growth. Additionally minimum electrolyte leakage was also noticed in plants irrigated with canal water. Plants irrigated with water having EC 3 dSm-1 ranked 2nd and considerably showed better germination and for other studied parameters. The salinity at 6, 9 and 12 dS m-1 caused simultaneously undesirable impact on all the investigated traits with the exception to electrolyte leakage of leaf that augmented parallel to the elevated salt stress conditions. In case of genotypes “Halo Blush” performed better for most of the investigated traits as compared to “Scarlet Eye” This indicates that Halo Blush had more tolerance to salinity as compared to Scarlet Eye.