ROCKVILLE, Md.--Celera Genomics announced that Celera AgGen, its agricultural business, has formed a three-year agreement with RhoBio, a joint venture between Rhone Poulenc Agro and Biogemma, to use expression studies to discover genes related to traits of importance in maize. AgGen, formerly a part of Perkin-Elmer's Biosystems division, was adopted by Perkin-Elmer's Celera business unit in January. AgGen will receive royalties from RhoBio resulting from sales of any products developed through this research-based alliance.