Glossary Plant Breeding

Recombinant Frequency. A ratio of the number of recombinant cells (individuals) to the
total number of cells (individuals). The mean recombination frequency never exceeds
the limit of 50 per cent (0.5) as only two chromatids out of four take part in crossing
over at any one point of time.
Recombinant Inbred Lines (RIL). A set of inbred lines, each derived independently,
usually by selfing single plants within lines during a number of filial generations. In
plant breeding, individual RIL are often derived by single seed descent from a
backcross of the F 2 to one or the other parent. Each RIL is ultimately expected to have
a different pattern of alternative alleles of multiple loci within an otherwise unique
homozygous genetic background, allowing effects of individual alleles (or
combinations of alleles) to be evaluated in an otherwise homozygous background).
Recombinant. A cell or an individual with a genotype produced through recombination.
Recombination Gene. Any gene (allele) that controls the frequency of genetic
recombination. Such genes may be concerned with the structure of an enzyme or the
structure of a regulatory substance that influences genetic recombination.
Recombination. Formation of new combinations of genes as a result of segregation in
crosses between genetically different parents;.also the rearrangement of linked genes
due to crossing over.
Recombinational Repair. A mechanism for the repair of a DNA lesion through a
process, similar to recombination, which uses recombination enzymes.
Recombined Triticales. See Triticales.
Recon. Aregionofagenewithinwhichtherecanbenocrossing-over(recombination),
now known to be a nucleotide pair.
Recurrent Parent. The parent to which successive backcrosses are made in the back
cross breeding. It is usually an agronomically sound variety under cultivation. It is
usually composed of a number of closely related pure lines (putative isogenic lines)
that interact synergistically to give the recurrent parent its agricultural characteristics.
However, it is deficient in one or a few characters.
Recurrent Selection (for GCA). A form of recurrent selection in which a number of
desirable plants on the basis of performance of their testcrosses with a heterozygous
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