ABSTRACT
Comparative in vitro screening of carrot cultivars for heavy metal tolerance during germination and early seedling growth

Ecem Kara1*
 
Heavy metal pollution in agricultural production can negatively affect seedling formation and development, and variety-specific tolerance in carrots (Daucus carota L.) during early developmental stages has not been sufficiently characterized. This study aimed to compare the in vitro responses of two carrot cultivars, Esvet and Scarlet Nantes, to Cu, Cd, Pb, Co, and Ni during germination and early seedling growth. Sterilized seeds were cultured in MS medium supplemented with 0, 100, 300, or 500 µM of each metal, and germination percentage, mean germination time, germination speed index, shoot and root length, and fresh and dry weights were evaluated. Heavy metal stress significantly affected most germination and growth characteristics, and responses varied depending on the cultivar and dose (p < 0.05 or p < 0.001). ‘Esvet’ generally showed higher tolerance than ‘Scarlet Nantes’. Under Cu stress, the average germination speed index was 42.62 in ‘Esvet’ and 16.14 in ‘Scarlet Nantes’, while the average shoot length was 34.29 and 19.83 mm, respectively. Increasing metal concentrations significantly reduced seedling development. Under Cu, the average root length decreased from 68.55 mm in the control group to 8.47 mm at 500 µM, while under Ni, shoot and root lengths decreased to 5.85 and 2.15 mm, respectively, at the highest dose. Low Pb and Co doses increased the germination percentage to 72.50% and 71.00%, respectively, but seedling performance remained lower than the control group. Overall, Ni showed the strongest inhibitory effect on early growth, and ‘Esvet’ was the more tolerant cultivar.
Key words: Cultivar tolerance, Daucus carota, germination, heavy metal stress, in vitro screening, seedling growth.
1Sivas University of Science and Technology, Faculty of Agricultural Science and Technology, Sivas 58000, Türkiye.
*Corresponding author (ecemkara33@gmail.com).
Received: 20 April 2026; Accepted: 24 June 2026, Available online: 7 September 2026.