Data analysis using MEGA

Hi all,

I am working on DNA barcoding of Dalbergia  in India. Currently, I am analysing the different loci using MEGA 5. My question is while constructing NJ tree which option should I select, uncorrected p-distance or kimura-2-parameter? I have seen papers using either of them and I also read that there is no considerable difference in output. Can anybody help me to understand both the parameters correctly?

Thanks in anticipation

Best regards

Rasika