Davood Javadi mojadad - Agriculture Research, Education and Extension Organization (AREEO), Gilan, Iran
Javad Farrokhi - Academic Center of Education, Culture and Research (ACECR), Ardabil, Iran
Mehran Ouchi Ardabili - Academic Center of Education, Culture and Research (ACECR), Ardabil, Iran
Ebrahim AbediGheshlaghi - Agriculture Research, Education and Extension Organization (AREEO), Gilan, Iran

Hazelnuts, genus Corylus (2n=2x=22), are primarily small trees or shrubs which are grown mostly for their nuts(Tobin, 2009). They are wind-pollinated and their blooming occurred in the early spring. This genus has twenty identified species all over the world. Among the species the avellana is the most famous because of its edible nuts. Hazelnut (Coryllus avellana.L)is an ancient fruit crop in Iran and there are some extremely abundant germplasm resources for it (Erfatpouret al., 2011). Iran with an annual production of 14,299 tons is the seventh hazelnut producer in the world (FAO STAT, 2012). It also has a mean hazelnut yield of 698.7 kg ha-1, which is lower than the mean yield at the global level (1271.3 kg ha-1) (FAO STAT, 2012).