Woody plants provide many challenges to the tissue culturist. Although there are many excellent tissue culture books and manuals available, these are generally strongly biased towards herbacious crops. Consequently, they often do not pay sufficient attention to the problems that specifically apply to in vitro culture of tree species. Culture of the latter often poses problems which are either absent or of lesser significance when culturing herbacious species.
When trees in the field are used as explant source, the problems can be especially severe. For example, the...

2. IMPORTANCE OF NITROGEN METABOLISM 2. 1. Range of naturally occurring nitrogenous components in forest trees 2. 2. Gene expression and mapping 2. 3. Metabolic changes in organized and unorganized systems 2. 4. Nitrogen and nutrition 2. 5. Aspects of intermediary nitrogen metabolism 3. NITROGEN METABOLISM IN GROWTH AND DEVELOPMENT 3. 1. Precultural factors 3. 2. Callus formation 3. 3. Cell suspensions 3. 3. 1. Conifers 3. 3. 2. Acer 3. 4. Morphogenesis 3. 4. 1. Nitrogen metabolism of natural embryos 3. 4. 2. Somatic embryogenesis 3. 4. 2. 1. Sweetgum (Liquidambar styraciflua) 3. 4. 2. 2....