Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 193

In this design, each member of a group of parents used as males is mated to each member of another group of parents used as females. Design II is a factorial mating scheme similar to Design I (Figure 4.6). It is used to evaluate inbred lines for combining ability. The design is most adapted to plants that have multiple flowers so that each plant can be used repeatedly as both male and female. Blocking is used in this design to allow all the mating involving a single group of males to a single group of females to be kept intact as a unit. The design is essentially a 2‐way ANOVA in which the variation may be partitioned into difference between males and females and their interaction. The ANOVA is as follows:

Figure 4.6 North Carolina Design II. (a) This is a factorial design. (b) Paired rows may be used in the nursery for factorial mating of plants.

Source	df	MS	EMS
Males	n1 – 1	MS1	σ2w + rσ2mf + rnσ2m
Females	n2 – 1	MS2	σ2w + rσ2mf + rn1σ2f
Males × females	(n1 – 1)(n2 – 1)	MS3	σ2w + rσ2mf
Within progenies	n1n2(r − 1)	MS4	σ2w

The design also allows the breeder to measure not only GCA but also SCA.