testcross

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test·cross

(test'kros),
Crossing of an unknown genotype to a recessive homozygote so that the phenotype of the progeny corresponds directly to the chromosomes carried by the parents of unknown genotype.
Synonym(s): backcross (2)

testcross

(tĕst′krôs′, -krŏs′)
n.
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·crossing, test·crosses
To subject to a testcross.
Testcrossclick for a larger image
Fig. 295 Testcross. A testcross to find the genotype of the unknown parent.

testcross

a cross in which one partner is homozygous (see HOMOZYGOTE for the recessive alleles of the genes being investigated. The testcross progeny will indicate the GENOTYPE of the unknown parent. See Fig. 295 . Test crosses are used extensively in experiments to establish GENETIC LINKAGE. See also BACKCROSS.
References in periodicals archive ?
Overall [R.sup.2] of the QTLs detected for the RILs, testcrosses, and [H.sub.MP] were 15.59, 13.48, and 25.50%, respectively.
While the IR24 allele increased SF by1.04%, the Zh9A/IR24 heterozygote increased SF by 10.88 and 10.09% in testcrosses and [H.sub.MP], respectively.
The following will describe the three point testcross exercises in detail; however, the dihybrid testcrosses (see above) are identical except for replacing [y.sup.1] with [y.sup.+] in all stocks.
For testcrosses, Monsanto company analyzed whole kernel samples by near infrared transmittance (NIT) with an Infratec Grain Analyzer.
207 g [kg.sup.-1] (LS[D.sub.0.05] = 17 g [kg.sup.-1]) as were A632/OF9 testcrosses with values of 180 vs.
Expectation of means and variances of testcrosses produced from [F.sub.2] and backcross individuals and their selfed progenies.
Likewise, no significant changes were observed between testcrosses of generations [F.sub.1], [F.sub.2], [F.sub.2]-Syn1, [F.sub.2]-Syn2, and [F.sub.2]-Syn3 for all crosses and both traits.
[S.sub.2] progenies that produced testcrosses in the top 10% for yield in the 1999 trials were selected and testcrossed to two non-BSSS proprietary inbreds (Golden Harvest IN504 and IN354) during the winter season of 2000-2001.
On the basis of the selection index, 80 backcross progenies were selected for evaluation in testcrosses. Testcrosses of the selected backcross progenies (LH185 was tester) were produced in 1997 and evaluated in two replications at five Iowa locations in 1998.
The objective of this study was to evaluate falcata genotypes from a broad range of wild and semi-improved populations for performance per se and in testcrosses with elite sativa tester genotypes.
Identification of QTL for ADF (acid detergent fiber, closely related to NDF) was strongly dependent on the tester used to create maize (Zea mays L.) testcrosses, showing almost no correspondence in QTL across testers (Lubberstedt et al., 1997).
The corresponding testcrosses evaluated in the same environment were far less affected by the unfavorable weather conditions.