In modern molecular biology and genetics, the genome is the entirety of an organism’s hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA. Genomes are more than the sum of an organism’s genes and have traits that may be measured and studied without reference to the details of any particular genes and their products. Genome composition is used to describe the make up of contents of a haploid genome, which should include genome size, proportions of non-repetitive DNA and repetitive DNA in details. Duplications play a major role in shaping the genome. The present book explores current approaches in the study of chromosomes, cytotoxic effects, biotechnological potential of crop residues, plant diseases evaluation, biocontrol methods and evaluation by molecular methods, micropropagation, protoplast fusion and molecular modelling uning bioinformatics. The book will be very useful for students, teachers and researchers in the allied fields.