Abstract

 
In vitro proliferation of walnut (Juglans  regia var. zeiabadi) was studied  in  response  to  the  four  levels
(1/3X,  1/2X,  1.0X  and  1.5X)  of  macrominerals  of  DKW  (Driver  and  kunjyukj,  1984)  medium. 
Macrominerals (N, P, K, Mg) can be a  limiting factor for growth quantity (fresh weight and dry weight)
and growth  quality  (explants  appearance)  of walnut  explants. Addition of  0.5X macrominerals  to  the
basal DKW medium  in which containing 4.0 µM 6-benzylaminopurine  (BA) and 12 µM  indole-3-butyric
acid  (IBA),  significantly  (P=0.05)  improved  the proliferation.   Better  response of was  found with  1.5X
macrominerals  concentration  in  respect  of  growth  and  proliferation.    In  contrary,  the  decrease  in
mineral availability observed in the depressed growth in the low macrominerals supply treatments (1/3X
and  1/2X),  (the  restricted  mineral  availability  was  the  main  cause  of  the  inhibition  of  the  growth).
However,  root  formation was worsted by supplemented additional minerals. For example,  low mineral
concentration  treatment exhibit high  rooting ability  (75%) and high mineral concentration showed  low
(13%).