My understanding is that you don't need a tracker when using the DHT. I'm not sure what the bootstrap method is to find the initial peers to start accessing the DHT, but once you've found one peer, it's easy enough to find more. Feel free to correct me.
Thats nonsense. The clueless torrent news sites like to boast that you dont need a tracker for dht, just a 'bootstrap node'. Whick is exactly a tracker.
Its one simple node which address is hardcoded in the clients. So, it is a tracker, just not a full bittorrent tracker.