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 (tĕst′krôs′, -krŏs′)
A cross between an individual exhibiting the dominant phenotype of a trait and an individual that is homozygous recessive for that trait in order to determine the genotype of the dominant individual.
tr.v. test·crossed, test·cross·ing, test·cross·es
To subject to a testcross.


(ˈtɛstˌkrɒs) genetics
(Genetics) a genetic test for ascertaining whether an individual is homozygous or heterozygous
vb (tr)
(Genetics) to subject to a testcross


(ˈtɛstˌkrɔs, -ˌkrɒs)

a genetic test for heterozygosity in which an organism of dominant phenotype, but unknown genotype, is crossed with an organism recessive for all markers in question.
test′-cross`, v.t.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.testcross - a cross between an organism whose genotype for a certain trait is unknown and an organism that is homozygous recessive for that trait so the unknown genotype can be determined from that of the offspring
hybridisation, hybridization, hybridizing, interbreeding, crossbreeding, crossing, cross - (genetics) the act of mixing different species or varieties of animals or plants and thus to produce hybrids
References in periodicals archive ?
For hybrid production, the few existing published studies have been based on testcrosses to infer the combining capacity of lines at generations [S.
Four possible exercises are presented: two dihybrid testcrosses (Figure 2A,B) and two trihybrid testcrosses (Figure 2 C,D).
4] lines per se and the testcrosses were evaluated at Sinematialli under Striga-free conditions and at Ferkessedougou under artificial infestation with S.
4] stage of inbreeding, 450 to 500 lines derived from each population were evaluated for general combining ability in testcrosses and for performance per se in replicated trials at Ferkessedougou (9[degrees]30'N, 5[degrees]10'W), and Sinematialli (9[degrees]37' N, 3[degrees]04' W) both in Cote d'Ivoire which are hereafter referred to as Ferke and Sine, respectively.
The random nongenetic effects had a normal distribution with a mean of zero and were scaled so that broad-sense heritability among testcrosses was H = 0.
In the testcrosses, metaphase I chromosome pairing configurations of 13" + t1" + t' indicated that a spontaneous homoeologous translocation had occurred in the double-monosomic B[C.
2] testcrosses with Iowa Stiff-Stalk Synthetic (BSSS) related single-cross tester B73/B94 were produced in 1993 and evaluated in trials at one site with conventional-tillage and one with minimum-tillage, near Wooster, and at an additional site near South Charleston, OH, in 1994.
To provide an indication of the yield levels of these lines in hybrid combinations, grain yields of their testcrosses recorded under Striga infestation in different trials are presented in Table 1.
1] plants derived from the testcrosses Wichita//(Dn1/Dn2) (105 plants), Wichita//(Dn5/Dn2) (57 plants), and Wichita//(Dn6/Dn1) (67 plants) showed no segregation for RWA susceptibility.
Each trait was modeled as a function of the following effects: locations, sets nested in locations, location-set interaction, replications nested in location-set interaction, populations, location-population interaction, location-set-population interaction, testcrosses nested in set-population interaction, and location-testcross interaction nested in set-population interaction.