I would suggest doing a smaller scale pilot experiment that you can then scale up. be sure to include 0 salt, then a very low level you think your species will tolerate, then a level 3x higher, 10x higher, etc until it’s toxic or clearly inhibited

you could use only wt and 30 seeds per level

this test would you figure out how much salt for a dose response curve

hope this helps!

Amy, thank you so much! I appreciate your response. Yes, actually, you're right—I need to start with a small number of seeds. So, for each concentration, for example, 50 mM, I will use only one plate (a round plate with three genotypes). Then, I will do the same for 100 mM and 150 mM at the same time. After that, I will analyze the data, which will take some time, and I might use a t-test and ANOVA.

Hello Maryam,

Your initial first small check won't necessarily need a stats test, you're just trying to find a range of salt that will give you normal growth (or nearly so) and strong inhibition. Once you find out that range, you'll need to subdivide into several concentrations. Try a small-scale test of that range before using a larger number of seeds.

Some plants are quite sensitive to salt and won't even germinate so it may take more than one try to find out how low to go.

If you want to try root length, orient the plates vertically. Then you can photograph (or scan with a flatbed document scanner, or even a gel imager) and digitally measure lengths even if the roots are curved or wavy.

Thank you so much, there were no germinate at 150mM NacL

Hi Maryam,

Ok, that gives you a place to start! I would suggest trying 0 mM, 5 mM, 15 mM, and 50 mM for the next test. Hopefully you'll start to see some germination on the lower levels.

The 0 mM let's you know the overall seed viability (that can be an issue, depends on your species and how fresh the seeds are).

Good luck!