Principles of Plant Breeding (2+1)

Comparison of pure line and mass selections

	Pure line selection	Mass selection
1.	The new variety is a pureline		The new variety is a mixture of purelines.
2.	The new variety is highly uniform. In fact, the variation within a pureline variety is purely environmental.		The variety has genetic variation of quantitative characters, although it is relatively uniform in general appearance.
3.	The selected plants are subjected to progeny test.		Progeny test is generally not carried out.
4.	The variety is generally the best pureline present in the original population. The pureline selection brings about the greatest improvement over the original variety.		The variety is inferior to the best pureline because most of the purelines included in it will be inferior to the best pureline.
5.	Generally, a pureline variety is expected to have narrower adaptation and lower stability in performance than a mixture of purelines.		Usually the variety has a wider adaptation and greater stability than a pureline variety.
6.	The plants are selected for the desirability. It is not necessary they should have a similar phenotype.		The selected plants have to be similar in phenotype since their seeds are mixed to make up the new variety.
7.	It is more demanding because careful progeny tests and yield trials have to be conducted.		If a large number of plants are selected, expensive yield trials are not necessary. Thus it is less demanding on the breeder.