File Name: test cross and backcross .zip
The triple test cross analysis of Jinks and Perkins was used to study different components of genetic variation in four barley F 2 populations, C x IB , C xJyoti, IB xP and DL 3xP , for final plant height, spike length, kernel weight, grain yield per plant and harvest index. Both the additive D and dominance H components were highly significant for all the five characters in all four crosses.
The first scientific explanation of inheritance was given by Mendel in He performed a series of experiments on garden pea in a scientific manner and proposed rules. His work is known as Mendelism. Reasons for Selection of Garden Pea by Mendel:. Monohybrid Cross:.
Test cross and backcross are two types of crosses introduced by Gregor Mendel. In test cross, a dominant phenotype is crossed with the homologous recessive genotype in order to discriminate between homologous dominant and heterozygous genotypes. In backcross, the F1 is crossed with one of the parents or genetically identical individual to the parent. The main difference between test cross and the backcross is that test cross is used to discriminate the genotype of an individual which is phenotypically dominant whereas a backcross is used to recover an elite genotype from a parent which bears an elite genotype. What is the difference between Test Cross and Backcross. The breeding of a dominant phenotype with the recessive phenotype is referred to as a test cross.
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A test cross is a cross between an organism that is heterozygous for one or more genes for example, Ww and an organism that is homozygous for the recessive alleles for example, ww. The former have the dominant phenotype because W is dominant over w, and the latter have the recessive phenotype. A test cross is often extremely useful for genetic analysis. Test crosses are used to test an individual's genotype by crossing it with an individual of a known genotype. Dihybrid test cross: Dihybrid test cross is a cross between an organism that is heterozygous for two genes and a second organism that is homozygous recessive for two genes. A test cross is a way to explore the genotype of an organism. Earlier use of the test cross was as an experimental mating used to determine which allele are present in the genotype.
Under the law of dominance in genetics , an individual expressing a dominant phenotype could contain either two copies of the dominant allele homozygous dominant or one copy of each dominant and recessive allele heterozygous dominant. In a test cross, the individual in question is bred with another individual that is homozygous for the recessive trait and the offspring of the test cross are examined. From , Thomas Hunt Morgan conducted test crosses while determining the inheritance pattern of a white eye-colour mutation in Drosophila. Test crosses have a variety of applications. Common animal organisms, called model organisms , where test crosses are often used include Caenorhabditis elegans and Drosophila melanogaster.
Backcross , the mating of a hybrid organism offspring of genetically unlike parents with one of its parents or with an organism genetically similar to the parent. The backcross is useful in genetics studies for isolating separating out certain characteristics in a related group of animals or plants. In animal breeding , a backcross is often called a topcross. Backcross Article Additional Info.
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The below mentioned article will highlight the two types of experiment performed by Mendel. When F 1 individuals are crossed with one of the two parents either CC—red flowered or cc—white flowered from which they have been derived, then such a cross is called back cross. A When F 1 Cc is crossed to the parent with dominant phenotype i.
The technique of crosses used is repeated selection that is to make a cross between selected families recombination by means of free crossing. The number of cross-test of 5 selected families and 5 varieties of comparison parents with 2 replications. Each line represented 5 sample plants, so the total sample of plants. The results showed that from 5 selected families who crossed with their parents as a whole can improve the phenotype character. The selected local waxy corn has a superior appearance of the phenotype character. Pemuliaan jagung khusus. Balai Penelitian dan Pengembangan Pertanian Puslitbang.
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