You might lose the new growth but since it is a seedling it will probably survive.

keep it out of direct sun and keep it watered. I snapped the taproot to one of my mango trees transplanting it, it went into decline for a short period but eventually pulled through, you picked a good time to repot, the rainy seasons coming

I was kicking myself hard. That tap root broke off around 3+ " from the end of the trunk. There wasn't a lot of left of the tap root but there was a good amount of smaller roots around it so hopefully it won't die.
Bryan it has been raining so hard everyday I almost drowned twice today. My trees are going crazy because of all the rain. I wanted to make sure they had fresh soil to go with all this rain so I wouldn't worry while I was away.
Thank to yo guys for making me feel better about maming my favorite little seedling!

Mango seedlings are tough buggers. As long as you don't over-fertilize them, they are pretty hard to kill. I purposely snip off the tap root when transplanting mango seedlings from seeding trays into 1G pots to encourage lateral root growth. As Sheehan said, there is the potential that you lose the new growth flush, but the seedling should be fine.

Jeff

Well Jeff this seedling just as you said-- is one tough bugger! The new growth did shrivel up but it is already recovered and pushing lots of new growth. The question I have is this: will the tap root regrow or does the smaller roots just take over? I am happy either way that it's doing so well.

Smaller roots will take over (and will eventually thicken up), but it will be perfectly fine.

Jeff