Sources of Resistance and Methods of Testing for Resistance

Abstract

Genetic variation is the prerequisite in any breeding programme. In case of breeding resistant varieties to diseases and insect pests, it is imperative to search for sources of resistance, i.e. the donors from which the resistant gene(s) may be transferred. The first step, therefore, is to collect variability including the wild/weedy relatives and land races of that species in which improvement in resistance to disease (s) and/or insect(s) is desired. Once the variability is collected, the next step is to screen the available gene pool against the important parasites. The resistant lines of immediate use may be included in the core germplasm which is used in hybridization. The rest of the lines may be kept in cold storage after proper classification. These germplasm lines may be grown in alternate years to revitalize their viability, etc. These may be screened against new parasites as and when they become important.