Host resistance is one of several classical approaches to virus disease control. The others are cure of the disease (i.e., by chemotherapy, thermotherapy, or meristem culture), maintenance and use of pathogen-free seed or propagules (i.e., by use of seed certification and tissue culture techniques), restriction of long-distance movement of the pathogen into new areas (quarantine), restriction of local dissemination into and among crop plants, and restriction of deleterious effects of disease. Despite these approaches, many viruses still are causing serious economical problems. Among all of these approaches, plant resistance is the most desirable and practical. Resistance in plants may be inherent (genetic) or induced. Genetic resistance has long been considered the ideal approach to disease control. Once achieved, it has the potential of replacing all other approaches, is easy and inexpensive to apply, has no undesirable environmental impact, and requires no induction. However, suitable resistance genes frequently are not available in genetically compatible germplasm. When they are, many years may be required for their incorporation into cultivars with other desired characteristics. Transfer of genes from related species is sometimes possible, employing ploidy manipulation, embryo rescue, protoplast fusion, and other difficult technologies, but these genes frequently are inseparably linked to undesirable characteristics. 1 Furthermore, most plant virus resistance genes are not fully effective or universally applicable against all isolates of the virus.
All Science Journal Classification (ASJC) codes
- Agricultural and Biological Sciences(all)