Bi Parental is a of, relating to, involving, or derived from two parents.
Parental investment theory is a branch of life history theory. The earliest consideration of parental investment is given by Ronald Fisher in his 1930 book The Genetical Theory of Natural Selection.
Main Features of Biparental Design:
This design basically involve three generation F2, P1 and P2.
Bi Parental requires three cropping season, to produce experimental material and fourth season which is basically used for evaluation purpose.
Bi Parental design provides information, about additive and dominance genetic variance.
The design is very useful in, selection of breeding procedure for genetic improvement of different polygenic characters.
The analysis of bi-parental design, is based on second order of statistics. The analysis of this design is more difficult than generation mean analysis.
Bi Parental design basically includes, full sib and half sib progenies in the mating programme.
The analysis of biparental, cross is based on eight which are given below.
Steps in Bi-Parental Mating Design
There are six steps involved in Bi Parental mating.
1: Selection of Parents
The first step is selection of parent for crossing purpose. The parents which are selected should have contrasting characters. So for these pure lines are selected as parent.
2: Making Original cross
Second step after selection of contrasting parents, pure lines, or strains are crossed to produce to F1 seed.
3: Growing F1 and F2 Progeny
Then the F1 seeds which are, produced by crossing two contrasting parents are raised. All F1 plants are self-pollinated to obtain F2 seed which, is used basically to raise F2 population.
4: Making Crosses in F2
Large F2 population which are basically grown .In F2 populations, several single plants which are selected randomly.
5: Evaluation of Crosses
All possible single crosses are made which are randomly, selected plants from F2 population are basically evaluated in, replicated trials. The observation are recorded on the basis of various quantitative characters.
6: Bio-metrical Analysis
The data which is obtained are subjected to bio-metrical analysis.
Advantages of Bi Parental:
It permits evaluation of segregating population of individual cross which is made between two inbred lines.
It provides information about, additive and dominance variance.
It is very effective in breaking undesirable linkages.
It is source of creation of genetic, variability in a population through heterzygosity.
This design can be used for both self and cross pollinated species.
Disadvantages of Bi Parental:
It does not allow combination of several different generation of a cross which can be evaluated in a single analysis.
It is not applicable to segregating population, of three way, double and multiple crosses.
This design is applicable for simultaneously evaluation of several segregating crosses.
It does not provide any information about, epistasis variance.
This design requires three cropping season, so evaluation procedure is lengthy.
As analysis of this design is based on eight assumption which are seldom full filled.
Analysis of Biparental cross is more difficult than generation mean analysis.