selecting hazelnut (corylus avellana l.) rootstocks for different climatic conditions of iran

hazelnut is grown in limited areas of iran with high rainfall and high relative humidity. new cultivars and rootstocks that are tolerant of drought and low humidity are needed to expand hazelnut cultivation. to this end, seeds of 14 local corylus avellana l. genotypes (a1, a2, gerche, gerde eshkevarat, gerde shok, mahalli karaj, nakhon rood, navan1, navan7, navan9, navan10, pashmineh, shirvani and sivri) with relative tolerance to environmental stresses were collected in different areas and sown with seedlings of controls negret and daviana. seed germination, growth characteristics, graft success and chlorophylls of all rootstocks were evaluated. based on the results, first-year seedlings of six genotypes with high germination and growth vigor were selected and transplanted for field evaluation. results of the first year showed that seeds of greche had the highest (69%) germination, and that genotypes nakhon rood and sivri had the longest stems (18.22 and 12.44 cm, respectively), while pashmineh and nakhon rood seedlings had the thickestshoot diameter (2.45 and 2.42 mm, respectively). in the second year, mahalli karaj and nakhon rood seedlings showed the greatest shoot length and diameter. the highest a and b chlorophyll levels were detected in nakhon rood seedlings (3.44 and 1.39 mg/per gram of leaf fresh weight, respectively). grafts on shirvani and sivri rootstocks were the most successful, with 42.18 and 41.07%, respectively. graft success was not different among different scions.