Resistance Breeding in Ornamental Plants: An Overview

This chapter highlights Resistance breeding in ornamental plants. Use of resistant varieties leads to reduction in the use of pesticides which in turn results in reduction of environmental pollution and health hazards caused using pesticides. Moreover, genetic resistance protects natural enemies of insect pest which are killed by insecticides. A series of studies have been conducted for the identification and cloning of genes capable of increasing tolerance to environmental stresses like drought, freezing, heat, salinity, metal toxicity, hypoxia, and UV-B radiation. Somaclonal variation has contributed to the development of abiotic stress resistant varieties in major crops. Mutation techniques including transposon mutagenesis have made to the understanding of the molecular basis of the plant stress response based on the information gathered from the Arabidopsis and other model studies. Other methodologies used to develop new genotypes tolerant to cold, drought and salt are wide distant hybridization, In-vitro mutagenesis and genetic engineering. Breeding for biotic stress resistance deals with defense mechanisms and strategies that protect host plants against pests and pathogens, inheritance of resistance genes and durable effectiveness of resistance genes.