Seeing as they are single bladed leaves, I presume they are the lowest and first true leaves of your plant. The damage is most likely caused by splashing fertilizer on them when you are watering, or from being in contact with the wet soil. Unless this discoloration continues, I would suggest there isn't anything serious to be concerned about. Try to avoid getting fertilizer on the leaves and I am sure this problem will go away. Hope this helps..... Organoman.