Preferably, {HEAD ~ the regenerable cells} in such tissue cultures will be embryos, {TAIL ~ protoplasts}, meristematic cells, callus, pollen, leaves, anthers, roots, root tips, flowers, seeds, pods or stems 
be
Preferably , { HEAD ~ the regenerable cells } in such tissue cultures will be embryos , { TAIL ~ protoplasts } , meristematic cells , callus , pollen , leaves , anthers , roots , root tips , flowers , seeds , pods or stems
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH