Speakers - 2026

Title: Uncovering salinity tolerance in silybum marianum (l.) populations under field conditions

Abstract

Milk thistle (Silybum marianum L.) is an annual, herbaceous plant native to the Mediterranean region. It typically grows in flat plains with warm climates and light sandy soils. The seeds of this plant are the primary source of pharmacologically active compounds known as silymarin, which are widely used in the treatment of liver disorders and certain other diseases. Iran is among the regions characterized by saline soils and water scarcity; therefore, one of the practical strategies for coping with such adverse environmental conditions is the evaluation and utilization of salt-tolerant plant species such as Milk thistle. This study aimed to evaluate the salinity tolerance of different milk thistle (Silybum marianum L.) populations under different salinity levels at the Sadouq Research Farm was conducted with the National Salinity Research Center during the crop year (2024-2025). The experiment was conducted in a split plot in a randomized complete block design with 3 replications. The experimental treatment included four irrigation water salinity levels (3 dS/m, 6 dS/m, 9 dS/m, and 12 dS/m) as the main plot, and the subplot included six different populations (Golestan, Isfahan, Fars, Mazandaran, Ardabil, and Khuzestan). The measured parameters included plant height, thousand-seed weight, inflorescence yield and diameter, number of seeds per inflorescence, number of inflorescences per plant, seed yield, shoot dry weight, and grain harvest index. The results showed that salinity had a significant effect on all studied traits, but the effect of different plant populations, except for the number of seeds in the inflorescence, seed yield, and harvest index, was significant on other studied traits. The interaction effect of salinity in the population was significant only on plant height. In all the studied populations, plant height in the control treatment (salinity 3 dS/m) had the highest values and decreased significantly with increasing salinity. The highest height at salinity of 3 dS/m was observed in the Ardabil, Fars, and Golestan populations, about 70 cm, and the lowest values at the highest salinity level (12 dS/m) were observed in the Fars and Mazandaran, about 30 cm. The 1,000-seed weight of Mil; thistle decreased significantly with increasing salinity levels, with severe salinity (12 dS/m) leading to a 50% decrease in this key yield trait. The Ardabil and Khuzestan populations had the highest and lowest thousand-seed weight, respectively, with a difference of 15%. Inflorescence yield, inflorescence diameter, number of seeds per inflorescence, and number of inflorescences per plant decreased by 40, 22, 33, and 48 %, respectively, with increasing salinity from the control treatment (3 dS/m) to the highest salinity level (12 dS/m). The plant seed yield also decreased significantly with increasing salinity from the control treatment to 12 dS/m, so that it decreased by 53% compared to the control treatment. Overall, the results showed that the populations of Ardabil, Fars, Golestan, and Mazandaran were superior to the populations of Isfahan and Khuzestan.

The audience take away from your presentation:

• The audience can use the findings of this study to identify salt-tolerant milk thistle populations and apply this knowledge in saline agricultural regions. 
• The results help researchers, faculty members, and agronomists improve research, teaching, crop selection, and management under salinity stress. 
• This study also provides a practical solution for using medicinal plants such as milk thistle in areas affected by saline soil and poor-quality irrigation water. 
• It offers new field-based information that improves the accuracy of selecting suitable populations and understanding which traits are most affected by salinity. 
• In addition, it supports breeding programs, sustainable agriculture, better use of marginal lands, and the development of strategies for crop production in arid and semi-arid regions.