BREEDING METHODS IN CROSS-POLLINATED CROPS
Populations of cross-pollinated crop species are highly heterozygous as well as heterogeneous. Their genetic makeup is such that they show variable inbreeding depression. Consequently, breeding methods for cross-pollinated crop aim at preventing in breeding. The breeding methods commonly used in cross-pollinated crops may be grouped into two broad categories;
Hybrid and synthetic varieties.
In the case of population improvement, mass selection or its modifications are used to increase the frequency of desirable allels, thus improving the characteristics of populations.
In case of hybrid and synthetic varieties, a variable number of strains are crossed to produce a hybrid population, the strains that are crossed are selected on the basis of their combining ability.
The population improvement methods may be grouped into two general classes’
Without progeny testing – Plants are selected on the basis of their phenotype and number of progeny test is carried out. E.g. Mass selection.
With progeny testing
Progeny selection or Ear -to row method and Recurrent selection. Mass selection The plants are initially selected on the basis of their phenotype, but the final selection of plants that contribute to the next generation is based on progeny test. This class of population improvement includes;