The main rounds of the 25th Sub-Junior National Badminton Championships will be held at the Indira Gandhi Indoor Stadium from Sunday. After the three-day qualifying rounds, the event, for shuttlers in the 13-15 age bracket will continue till next Thursday. More than 1,000 players as well as 200 coaches and officials will participate in the tournament, hosted by Delhi Badminton Association. The event carries a prize money of Rs three lakh.