الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The genus Taxodium distichum belonged to the subfamily Taxodioideae of the family Cupressaceae or cypress family. The literature showed that Taxodiodeae is a minor subfamily containing three botanic varieties are (1) Taxodium d.in United States (USA) and Mexico (2) Glyptostrobus is natural to China, and (3) Cryptomeria in Japan.
The genetic difference inters the Taxodium distichum genus has been understood to be either containing of 3 separate types are T. distichum (L.) Rich. var. distichum (Bald cypress), T. distichum var. imbricarium (Nutt.) (Pond cypress) and T. distichum var. mexicana (Montezuma cypress).
The main importance for Taxodium d.plants is wood, which has been economically appreciated due to its flexibility, and heavily collected due to it is resistant to decay but is too soft, light, actual durable, and does not warp easily, in addation the author studied characteristics and availability of commercially important woods.
The genetic tools represented the genetic changes among many individual living organisms and different species. Commonly, genetic markers don’t characterize the main target gene but performance as flag and/or signs. There are three different genetic markers including the morphological, biochemical and DNA markers.
The usage of sequencing or nucleotide sequence variances in a one gene to examine the genetic relationship was commonly useful by Carl Woese, 2000. The author documented those sequences change in a conserved gene and rRNA, can be ulitlize to conclude phylogenetic relationship.
DNA barcodes or barcoding includes short sequences of DNA obtained from a particular region of plant genome and comparison them among and within species to current a “barcode” for species documentation.
DNA barcoding as new tools showed as promising tool for species identification in all organisms. DNA barcodes has developed a progressively significant tool for taxonomic investigations and species definition, besides for the discovery of new species.
Therefore, there is a major essential to examine the genetic background of Taxodium distichum species as significant plant genetic resources and also assessment the genetic differences of these species in Egypt.