What is diallel analysis?

Diallel mating design is used to evaluate several inbred lines in terms of combining ability variances and effects. Diallel cross refers to mating of selected parents in all possible combinations and evaluation of a set of diallel crosses is known as diallel analysis.

Why diallel analysis?

A diallel cross is a mating scheme used by plant and animal breeders, as well as geneticists, to investigate the genetic underpinnings of quantitative traits. In a full diallel, all parents are crossed to make hybrids in all possible combinations.

How diallel analysis is helpful for genetic studies?

Diallel crosses are also frequently used in genetic studies for determining mode of inheritance of the examined trait, as well as the number of genes that control the trait and gene effects. Hybrids have 25–30% higher seed yield than varieties. Besides that, hybrids have other advantages over varieties.

What is diallel design?

The diallel mating design generally estimates the variation of quantitative characters in the genetic components like assessment of plant seed quality. The estimation is also performed to deduce the combining ability of the different inbred lines which participate in the different crosses taken into consideration.

What is partial diallel?

A diallel is a mating system that involves all possible crosses among a group of parents. The partial diallel is one of many variations of the diallel (Griffing, 1956; Kempthorne and Curnow, 1961; Gardner and Eberhart, 1966) and consists of crosses among two parent groups.

What is general combining ability?

General combining ability (GCA) is directly related to the breeding value of a parent and is associated with additive genetic effects, while specific combining ability (SCA) is the relative performance of a cross that is associated with non-additive gene action, predominantly contributed by dominance, epistasis, or …

What is GCA and SCA?

 The term GCA is used to designate the average performance of an inbred line in hybrid combinations  SCA is used to designate those cases in which certain combinations do relatively better or worse than would be expected on the basis of the average performance of the lines involved.

What is partial diallel cross?

When the number of parents increases then it is not possible to handle these large number of crosses. In such cases we use partial diallel crosses in which we take a sample of crosses among all crosses in such a way that each parent is involved in crosses equal number of times(s).

Why partial Diallel cross is important?

Kempthorne and Curnow (1961) suggested the partial diallel cross to allow the evaluation of a greater number of inbred lines in crosses. According to this procedure, each of the n lines in the set are crossed with s other lines of the same set, instead of (n – 1) lines as in the complete diallel.

How do you find the general combining ability?

A General combining ability of Parent 1 should be interpreted as the deviation of a Cross from the mean of all crosses when Parent 1 is present. This can be represented as follow: GCA1 = Y1. – Y..

What are the different types of heterosis?

Types of heterosis

Euheterosis or true heterosis.
Mutational heterosis.
Balanced heterosis.
Pseudoheterosis or luxuriance.

How do you calculate GCA and SCA?

SE of GCA for lines = (MSE/r x t)1/2; SE of GCA for testers = (MSE/r x l)1/2; SE of SCA effects = (MSE/r)1/2; where MSE = mean square error from the analysis of variance table. A tester is a genotype that is used to identify superior germplasm in accordance with breeding objectives in a hybrid-oriented program.