Effect of explants density and size on the in vitro proliferation and growth of separated shoots of globe artichoke (Cynara cardunculus var. scolymus L.)

We investigate here the effect of the density and the size of explants on the in vitro proliferation of globe artichoke shoots (cynara cardunculus var. scolymus l.; accession 'art 21'). for this purpose,we examined the rate of proliferation of separated shoots according to their sizes (< 1 cm,1 to 1.5 cm,1.5 to 2 cm and > 2 cm),and their densities (3,4,6 and 7 shoots per 132 cm2 area of culture media) in the proliferation medium containing 1mg.l-1 kinetin and 1 mg/l-1 naa. the results showed that explants with a size comprised between 1-1.5 cm exhibited 100% rate of shoots survival and they give the highest number of new formed buds (7.33). in addition,we found that the density of 4 explants per 132 cm2 of culture medium area was the most suitable to promote budding and shoots proliferation and consequently increase the rate of multiplication. © 2017,university of mohammed premier,oujda morocco.