I have acquired data with multiple variables that I need to test. My dependent variable, Seed number, is tested between Ecotypes but also between Treatments (hot and cold). I need to see whether Seed Number between Ecotypes is the same when different Treatments are applied. In other words I might expect to see a difference in Seed Number between Ecotypes in the hot but not cold. The test is complicated by the fact that multiple repeats were taken that are likely to be significantly different and therefore grouping the repeats may confound the results.
I am using SPSS so any help there would be useful.