The way to interpret the p value for a Chi Square, is, what is the probability of the relationship measured is by random chance. Therefore, the finding is highly significant that the data did not happen by chance......something is going on with the Heat shock duration
If you select the Help Tool (?) and click on the Effect Likelihood Ratio Tests table you will get the following definition
Effect Likelihood Ratio Tests
Shows the likelihood ratio chi-square test of the null hypothesis that the parameter estimates for the effects of the covariates is zero.
Jim