Comparative Study of the Effect of Different Concentrations of Salinity on the Morphological and Molecular Characteristics of Lepidium sativum L. Using RAPD-PCR Markers

• Published in: Tikrit Journal of Pure Science Vol. 30; no. 3; pp. 30 - 41
• Main Authors: Abdullah Sultan, Rasha, Zaidan Al-Sugmiany, Rafea, Adnan Ibrahim, Mariam
• Format: Journal Article
• Language: English
• Published: Tikrit University 25.06.2025
• Subjects: Genetic markers, Lepidium sativum L., Mutations, RAPD-PCR, Salinity
• ISSN: 1813-1662; 2415-1726
• DOI: 10.25130/tjps.v30i3.1778

This study aimed to evaluate the effects of different salinity levels on the morphological and genetic traits of Lepidium sativum L. (garden cress). Three treatments using well water with varying salinity levels (5.30, 19.17, and 23.35 mg/L) were compared to a control irrigated with Tigris River water (0.80 mg/L). Parameters measured included germination time, plant height, number of leaves and branches, and chlorophyll content. Germination occurred first in M1 (18 hours), followed by M2 (24 hours), and M3 (72 hours), indicating an inverse relationship between salinity and germination speed. M1 plants reached the greatest height (30.67 cm), followed by M2 (30.02 cm), and M3 (16.28 cm). Leaf count was highest in M1 (23), then M2 (22), and lowest in M3 (10). Branch count peaked in M2 (7.1), followed by M1 (6.7), with M3 lowest (5.5). Chlorophyll content was highest in M2 (38.14 Soil Plant Analysis Development (SPAD)), then M1 (37.76 SPAD), and lowest in M3 (33.62 SPAD). Randomly Amplified Polymorphic DNA- Polymerase Chain Reaction (RAPD-PCR) analysis was conducted to assess genetic variation. A total of 135 bands were observed: 83 were absent and 52 unique. M2 showed the highest number of unique bands (20), followed by M3 (18), and M1 (14). For absent bands, M2 had 32, M1 had 29, and M3 had 22. The results demonstrate that increased salinity negatively affects germination, plant growth, and genetic diversity, with moderate salinity inducing more genetic variation than high or low levels.