分子标记（Molecular markers）.docVIP

分子标记（Molecular markers） Molecular Markers [edit this paragraph] [the concept of molecular markers] Molecular markers are genetic markers based on the mutation of nucleotide sequences in individual genetic material and are a direct reflection of the genetic polymorphism of DNA level. With several other genetic markers, compared with morphological markers, biochemical markers, cytological markers and DNA molecular markers have has the advantages of: most molecular markers for codominance, choice of recessive traits is very convenient; Genome variation is extremely rich, and the number of molecular markers is almost infinite; At different stages of biological development, DNA from different tissues can be used to mark analysis; Molecular markers reveal mutations from DNA; The expression is neutral, which does not affect the expression of the target character, and has no linkage with the bad character. The test method is simple and quick. With the development of molecular biology technology, now has dozens of DNA molecular marker technology, widely used in genetic breeding, genome mapping, gene location, construction of related species identification, gene pool, gene cloning, etc. The concept of molecular markers is broad and narrow. A generalized molecular marker is a genetic or detectable DNA sequence or protein. A narrow molecular marker is a specific DNA fragment that can reflect some variation in the genome of a biological individual or population. The ideal molecular markers must have the following requirements: (1) high polymorphism; (2) co-dominant inheritance, that is, using molecular markers to identify heterozygous and homozygous genotypes in diploid; (3) identify alleles explicitly; (4) spread across the entire genome; (5) in addition to the marks of special sites, the molecular markers are required to be evenly distributed throughout the entire genome; (6) neutral (i.e., non-genetic multi-potency); (7) the test method is simple and fast (e.g. experimental p