RENTON — Tight end Victor Marshall and defensive end Benson Mayowa, who participated in the Seattle Seahawks’ rookie minicamp over the weekend on a tryout basis, were signed on Monday, the team announced. Rookie linebacker Ramon Buchanan, who was signed as a free agent after the NFL Draft, was released. The 6-foot-4, 235-pound Marshall played at the University of British Columbia and Simon Fraser University in Canada after attending Juanita High School in Kirkland. He caught 40 passes in 2009 while at Simon Fraser and had 10 receptions in 2010 for UBC. Mayowa, a 6-3, 236-pounder, played the University of Idaho. He had three sacks among his 19 tackles last season.