Procedure of Pedigree Method
The selection of parents to be used in a cross is the most important step in a breeding programme based on hybridization. The selected parents are crossed to produce a simple or a complex cross.
F1 seeds are space planted so that each F1 plant produces the maximum F2 seed. Generally, 15-30 F1 plants should produce enough seed for a good F2 population size.
In F2, 2000-10000 plants are space planted to facilitate selection. About 100-500 plants are selected and their seeds are harvested separately.
Individual plant progenies are space planted; each progeny should have about 30 or more plants. Individual plants with desirable characteristics are selected from superior progeny. The number of plants selected in F3 should be preferably less than the number of F3 progenies. If the number of superior progenies is small the whole cross may be rejected.
Individual plant progenies are space planted; again desirable plants are slected mainly from superior progenies. The no of plants selected in F4 is generally less than that of the F4 progenies.
Individual plant progenies are planted according to the recommended commercial seed rate. Often three or more rows are grown for each progeny to facilitate comparison among progenies. The number of progenies must be reduced to manage the size in preliminary yield trials which is usually 25- 100 progenies.
Individual plant progenies are planted in multi row plot and evaluated visually. Progenies are harvested in bulk since they would have become almost homozygous. The progenies which are reasonably homozygous and have enough seed may be planted in a preliminary yield trial and inferior progenies are eliminated.
Preliminary yield trials with three or more replications are conducted to identify few superior lines. The progenies are evaluated for plant height, lodging and disease resistance, maturity, etc. Standard commercial varieties must be included as check for comparison. Two to five out standing lines if found superior to check would be advanced to the coordinated yield trials.
F8 – F10 Generation:
The superior lines are tested in replicated yield trials at several locations for desirable characters. During these trial lines are evaluated for yield, disease resistance, maturity, etc. a line that is superior to the best commercial variety for yield and other characteristics would be released as a new variety.
In F11 generation released var. is multiplies for distribution to the farmers. The breeder is responsible to supply the breeder seed to the N.S.C for production of foundation seed.