The pedigree method of breeding has advantages and disadvantages.

Advantages

_ Record keeping provides a catalog of genetic information of the cultivar unavailable from other methods.

_ Selection is based not only on phenotype but also on genotype making it an effective method for selecting superior lines from among segregating.

_ Using the records, the breeder is able to advance only the progeny lines in which plants that carry the genes for the target traits occur.

_ A high degree of genetic purity is produced in the cultivar, an advantage where such property is desirable. Disadvantages

_ Record keeping is slow, tedious, time consuming, and expensive. It places pressure on resources. Seeding and harvesting are tedious operations. However, modern research plot equipment for planting and harvesting are versatile and sophisticated to allow complex operations and record taking to be conducted, making pedigree selection easier to implement and hence widely used. Large plant

populations can now be handled without much difficulty.

_ The method is not suitable for species in which individual plants are difficult to isolate and characterize.

_ Pedigree selection is a long procedure, requiring about 10–12 years or more to complete, if only one growing season is possible.

_ The method is more suited for qualitative than for quantitative disease resistance breeding. It is not effective for accumulating the number of minor genes needed to provide horizontal resistance.

_ Selecting in the F2 on the basis of quantitative traits such as yield may not be

effective. It is more efficient to select among F3 lines planted in rows than selecting based on individual plants in the F2.

Modifications

The pedigree selection method is a continuous selection of individuals after hybridization. A discontinuous method has been proposed but is not considered practical enough for wide adoption. The breeder may modify the pedigree method to suit specific objectives and resources. Some specific ways are as:

_ The numbers of plants to select at each step may be modified according to the species, the breeding objective, and the genetics of the traits of interest, as well as the experience of the breeder with the crop, and resources available for the project.

_ The details of records kept are at the discretion of the breeder.

_ Off-season planting, use of the greenhouse, and multiple plantings a year are ways of speeding up the breeding process.

_ Early generation selection for yield in pedigree selection is not effective. This is a major objection to the procedure. Consequently, several modifications have been introduced by breeders to delay selection till later generations. Mass selection or bulk selection is practiced in the early generation.