Effects of salinity on some characteristics of forage sorghum genotypes at germination stage

ABSTRACT: To study the effect of salinity on germination stage of seven sorghum genotypes a controlled experiment was con ducted in Agricultural Research Center, Yazd, Iran. Treatments were 7 salinity levels, i.e. control (tap water), 5, 10, 15, 20, 25, 30 dS.m-1 and 7 genotypes of forage sorghum; KFS1, KFS2, KFS3, KFS4, MFS1, MFS2 and LFS56. The experiment was done as completely randomized design (CRD) arranged as factorial with three replicates. Results showed that germination rate was not reduced up to 5 dS.m-1. Increasing in saline treatments more than 10 dS.m-1 was consisted with a considerable reduction at the rate of germination. The lowest percentage of germination was observed with the treatment of 30 dS.m-1 by 48/8%. salt tolerance threshold values for sorghum genotypes at germination satge was 8.37 dS.m-1. Each increase in salinity level above the salt tolerance threshold, reduced the rate of germination by 1.64 percent. Among the genotypes, KFS2, KFS4 showed the highest rate of germination by the percentages of 81/7% and 81/2%, respectively. LFS56 showed the lowest rate of germination by the 10%. The highest length for root and shoot was observed for the control and 5 dS.m-1, respectively. As salinity increased, the shoots and root length decreased. Among the genotype KFS2, KFS3 and MFS2 showed the highest shoots length. As salinity increased root length was decreased as well as shoot length. KFS3 produced the highest root length. However root lengths for the KFS1, KFS2, KFS3, KFS4 and MFS2 were not significant. LFS56 had the lowest root length (Fig. 4). Comparison of all of the genotypes showed that KFS2 produced the highest shoot length and seed germination rate, so this genotype could be considered as a salt tolerant genotype at least at germination stage.