Effects of Salinity Stress on some Quantitative and Qualitative Characteristics of Alternanthera repens Genotypes: "Entire Leaf "and "Undulate Leaf"

In order to study the effect of salinity on some morphological, physiological and biochemical characteristics of Alternanthera repens, this project was carried out as a factorial experiment based on a randomized complete block design with four replications in a greenhouse. Two Alternanthera genotypes, "Undulate leaf" and "Entire leaf" were propagated through plant division, and grown hydroponically. After establishment of the plants, they were treated with 0 (control), 30, 60 and 90mM NaCl for 12 weeks. Results showed that effects of genotype and salinity were significant on all measured traits. Compared to the controls, plants height were reduced in plants grown under 90mM NaCl to 50 and 28 percent, in "Undulate leaf" and "Entire leaf", respectively. As salinity level increased, shoot fresh and dry weight and relative water content (RWC) decreased. Further, as salinity level increased, proline content, electrolyte leakage (EL) and anthocyanin content increased. Compared to the controls, plants grown under 90 mM NaCl showed 18.15 and 31.95 percent less RWC, 57.5 and 78.5 percent less chlorophyll, 407.5 and 670.4 percent more EL, and 382.4 and 177.8 more anthocyanin, in "Undulate leaf" and "Entire leaf", respectively. According to the results, "Undulate leaf" was more resistant to salinity compared to "Entire leaf". At 90 mM NaCl salinity, "Undulate leaf" could survive, while, "Entire leaf" was completely injured.