Research director Francis Martin inspects hazelnut tree roots in a greenhouse at the INRA (French National Agronomical Research Institute) laboratory in Champenoux near Nancy, April 1, 2010. The INRA research unit, lead by Martin, has sequenced the genome of the Perigord black truffle to better understand the symbiosis between trees and fungus, including truffles, to ameliorate it's natural growth. REUTERS/Vincent Kessler (FRANCE - Tags: AGRICULTURE ENVIRONMENT FOOD SCI TECH)