A cross made between cytoplasmic male sterile line and a test variety to identify maintainers and restorers.
Breeding of an organism of unknown genotype with a homozygous recessive individual to determine the unknown genotype. The ratio of phenotypes in the offspring determines the unknown genotype. testis pl. testes[Gk. testicle] The male reproductive organ, or gonad, in which sperm and reproductive hormones are produced.
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
a cross between an individual with dominant phenotype but unknown genotype and an individual with the recessive phenotype in order to determine the genotype of the individual with the dominant phenotype
Backcross to the recessive parental type, or a cross between genetically unknown individuals and a fully recessive tester to determine whether an individual in question is heterozygous or homozygous for a certain allele. It is also used as a test for linkage, i.e., to estimate recombination fraction.
A cross between an individual of unknown genotype or a heterozygote (or a multiple heterozygote) and a tester individual.