Abstract

In order to study the effects of salinity stresses on seed germination characteristics and seedling growth ofCalligonum, three species of Calligonum, namely, C. comosum, C. polygonoides and C. persicum were evaluated. Three separate experiments was carried out; Experiment 1: salinity in four levels of 0, 6, 12 and 18 dS/m NaCl, were applied and the traits; germination percent, germination rate, length and dry weight of plumule and radicle and Na⁺ concentration in seedling tissues were measured. In Experiment 2, non-germinated seeds from Experiment 1 were transferred into distilled water and then seed germination recovery was studied. In Experiment 3: two levels of salinity and three Calligonum species were conducted with three replications in pots and time course of survival percentage were recorded. Results showed that salinity reduced all the above mentioned traits. With increasing salinity the Na⁺ concentration in C. persicum increased more than the other two species.  The C. polygonoides species had the highest germination recovery index. The results of probit analysis showed that C. polygonoides has the highest Lt50 and salinity tolerance. Cluster analysis on the basis of studied traits and Ward's method revealed that there is a significant level of genetic diversity between the three species.

Key words: Calligonum, salt tolerance, LT50, probit analysis.