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.

testcross

Etymology: L, testum + crux, cross
1 a cross between a dominant and a recessive phenotype to determine either the degree of genetic linkage or whether the dominant phenotype is a result of a homozygous or a heterozygous genotype.
2 a subject undergoing such a test. See also backcross.
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 ?
The following will describe the three point testcross exercises in detail; however, the dihybrid testcrosses (see above) are identical except for replacing [y.
The F1 testcrosses should be cleared of adults three to four days after mating to avoid overcrowding the cultures.
For testcrosses, Monsanto company analyzed whole kernel samples by near infrared transmittance (NIT) with an Infratec Grain Analyzer.
Line per se means for oil and protein were significantly higher than for testcrosses, whereas for starch, line per se means were significantly lower than those of the testcrosses (Table 3).
Comparison of testcrosses produced from F2 and first backcross populations of maize.
Likewise, no significant changes were observed between testcrosses of generations [F.
Congruency of quantitative trait loci detected for agronomic traits in testcrosses of five populations of European maize.
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.
Average yield of the testcrosses across several states in the central and eastern Corn Belt during two seasons (1999 and 2001) was 95% of the mean of commercial check hybrids.
Testcrosses of the 62 backcrosses (LH198 was tester) were produced in 1997 for evaluation in two replications at five Iowa locations in 1998.
For total yield and individual harvest yields, selecting parental clones for intercrossing based on halfsib progeny testcrosses increased genetic gains two to nine fold over simple phenotypic recurrent selection depending on the mount of assumed within plot variation between clones.