A chlorophyll deficiency expressed as yellowing of leaves was observed in hazelnut (Corylus avellana L.) progenies. Segregation ratios approximated 3 green : 1 yellow, indicating control by a single recessive gene designated chlorophyll deficient #1, for which the symbol c, is proposed. ‘Barcelona’, ‘Butler’, ‘Compton’, ‘Lansing’, Willamette’, and the ornamental selection ‘Redleaf #3’ are heter...