There are some books on objective type questions on the subject of plant breeding and a very few on genetics but there is hardly any book, which deals with tissue culture, biotechnology, blochemistry or forestry. All these subjects are related as many postgraduate students of genetics and plant breeding take blotechnology as a minor subject whereas those of biotechnology take biochemistry or genetics and plant breeding as a minor subject. Chemistry is needed in forestry cause in forestry we make use of organic chemistry, blochemistry and plant anatomy and physiology and this study will help us manager the forest resources such as energy, materials and medicine. Tissue culture systems represent an area of major potential in tree biology, cell culture systems are ideally suited for investigations aimed at achieving a greater understanding of the cellular physiology and biochermistry of tree species. Over the years a number of tree species have been established in cell cuture and a variety of information has been obtained from such sources. We now have a greater understanding of the Influence of various factors on growth rate, mechanisms of resistance against microbial attack and secondary product biosynthesis. The present book has been designed to serve the students of plant breeding, genetics, biotechnology, biochemistry and forestry.