كليدواژه :
ازت ﻣﺎﯾﻊ , ﺑﺎﻧﮏ ژن , ﺑﺬر ﻣﺼﻨﻮﻋﯽ , ﺣﻤﺎﯾﺖﮐﻨﻨﺪهﻫﺎي اﻧﺠﻤﺎدي , ژرم ﭘﻼﺳﻢ
چكيده فارسي :
ﻫﺮ ﺳﺎﻟﻪ ﺻﺪﻫﺎ رﻗﻢ ﺟﺪﯾﺪ از ﮔﯿﺎﻫﺎن زﯾﻨﺘﯽ ﺗﻮﻟﯿﺪ و ﻣﻌﺮﻓﯽ ﻣﯽﺷﻮﻧﺪ. ﻫﺮ ﮔﯿﺎه زﯾﻨﺘﯽ ﯾﮏ ﺧﺰاﻧﻪي ژﻧﺘﯿﮑﯽ ﺑﺎ ارزش اﺳﺖ ﮐﻪ ﺑﻪﻋﻨﻮان ﯾﮏ ﻣﻨﺒﻊ ﺑﺮاي ﺑﺮﻧﺎﻣﻪﻫﺎي اﺻـﻼﺣﯽ ﻣـﻮرد اﺳﺘﻔﺎده ﻗﺮار ﻣﯽﮔﯿﺮد. در دﻫﻪي ﮔﺬﺷﺘﻪ ﯾﮏ اﻓﺰاﯾﺶ ﻫﺸﺪار دﻫﻨﺪه اي در ﺗﻌﺪاد ﮔﻮﻧﻪﻫﺎي ﻣﻨﻘﺮضﺷﺪه و در ﺣﺎل اﻧﻘﺮاض وﺟﻮد داﺷﺘﻪ اﺳﺖ. ﺗﻌﺪادي از ﮔﯿﺎﻫﺎن زﯾﻨﺘﯽ ﺑـﺎ ارزش از ﺟﻤﻠﻪ ﻻﻟﻪي واژﮔﻮن، ﺷﻤﺸﺎد ﺧﺰري، ﺳﻮﺳﻦ ﭼﻠﭽﺮاغ، ﺳﺮﺧﺪار و ﺑﺮﺧﯽ ارﮐﯿﺪﻫﺎ در ﻣﻌﺮض ﺧﻄﺮ اﻧﻘﺮاض ﻗﺮاردارﻧﺪ. ﺑﺮﺧﯽ از اﯾﻦ ﮔﻮﻧﻪﻫﺎ ﻋﻼوه ﺑـﺮ ارزش زﯾﻨﺘـﯽ، ارزش داروﯾﯽ ﻧﯿﺰ دارﻧﺪ. ﺑﻨﺎﺑﺮاﯾﻦ، ﺗﻮﺳـﻌﻪ ي ﺳـﺮﯾﻊ روﯾﮑﺮدﻫـﺎﯾﯽ ﺑـﺮاي ﺣﻔـﻆ و ﻧﮕﻬـﺪاري درازﻣﺪت ژرمﭘﻼﺳﻢ اﯾﻦ ﮔﻮﻧﻪﻫﺎي در ﺣﺎل اﻧﻘﺮاض ﺿﺮوري ﺑﻪﻧﻈﺮ ﻣﯽرﺳﺪ. ﺑﺴﯿﺎري از اﯾﻦ ﮔﯿﺎﻫﺎن در ﺑﺎﻧﮏﻫﺎي ﺑﺬر و ﯾﺎ ﺑﻪﻋﻨﻮان ﮔﯿﺎﻫﺎن زﻧﺪه در ﺷـﺮاﯾﻂ ﻃﺒﯿﻌـﯽ، ﻧﮕﻬـﺪاري ﻣﯽﺷﻮﻧﺪ. اﯾﻦ روشﻫﺎي ﻧﮕﻬﺪاري؛ ﻏﯿﺮﻗﺎﺑﻞ اﻃﻤﯿﻨﺎن، ﺳﺨﺖ و ﻫﺰﯾﻨﻪﺑﺮ ﻫﺴﺘﻨﺪ. ﺑﻨﺎﺑﺮاﯾﻦ، روﯾﮑﺮدﻫﺎي درونﺷﯿﺸﻪاي ﺑﻪﻋﻨﻮان روشﻫﺎي ﻣﮑﻤﻞ، اﺑﺰار ﻣﻬﻤﯽ ﺑﺮاي ﺣﻔﺎﻇﺖ ﺧﺎرج از ﻣﺤﻞ ﻃﺒﯿﻌﯽ ژرمﭘﻼﺳﻢ ﮔﯿﺎﻫﺎن در ﻧﻈﺮ ﮔﺮﻓﺘﻪ ﻣﯽﺷﻮﻧﺪ. اﻣﺮوزه، ﺣﻔﺎﻇﺖ ژرمﭘﻼﺳـﻢ ﮔﯿﺎﻫﺎن زﯾﻨﺘﯽ ﺑﺎ ﻓﻨﻮن ﻧﻮآوراﻧﻪ ﺑﻪوﯾﮋه ﺑـﺎ ﻓﻨـﺎوري ﺗﻮﻟﯿـﺪ ﺑـﺬر ﻣﺼـﻨﻮﻋﯽ ﮐـﻪ اﺟـﺎزه ي ﻧﮕﻬﺪاري درونﺷﯿﺸﻪاي )ذﺧﯿﺮهي رﺷﺪ آﻫﺴﺘﻪ و ﺣﻔﺎﻇﺖ اﻧﺠﻤـﺎدي ( ﻣـﻮاد ﮔﯿـﺎﻫﯽ را ﻣﯽدﻫﺪ، اﻧﺠﺎم ﻣﯽﺷﻮد. در ذﺧﯿﺮهي رﺷﺪ آﻫﺴﺘﻪ، واﮐﺸﺖﻫﺎي دورهاي ﮐﺎﻫﺶ ﻣﯽﯾﺎﺑﻨﺪ. ﺣﻔﺎﻇﺖ اﻧﺠﻤﺎدي، ذﺧﯿﺮهي رﯾﺰﻧﻤﻮﻧﻪﻫﺎ در دﻣﺎي ﺑﺴﯿﺎر ﭘﺎﯾﯿﻦ )ازت ﻣﺎﯾﻊ، 196- درﺟﻪ-ي ﺳﺎﻧﺘﯽﮔﺮاد/321- درﺟﻪي ﻓﺎرﻧﻬﺎﯾﺖ( اﺳﺖ. در ﭼﻨﯿﻦ دﻣـﺎﯾﯽ ﻫﻤـﻪ ي ﻓﻌﺎﻟﯿـﺖ ﻫـﺎي درون ﺳﻠﻮﻟﯽ ﻣﺘﻮﻗﻒ ﻣﯽﺷﻮﻧﺪ، ﺑﻨﺎﺑﺮاﯾﻦ از ﻧﻈﺮ ﺗﺌﻮري؛ اﯾﻦ ﻓﻦ، ﻧﮕﻬﺪاري ﻣﻮاد ﮔﯿـﺎﻫﯽ را ﺑﺮاي دوره ﻫﺎي ﻧﺎﻣﺤﺪود زﻣﺎﻧﯽ ﻣﻤﮑﻦ ﻣﯽﺳﺎزد. ﺣﻔﺎﻇﺖ اﻧﺠﻤﺎدي ﺗﻨﻬـﺎ ﻓـﻦ ﻗﺎﺑـﻞ دﺳﺘﺮس ﺣﺎل ﺣﺎﺿﺮ ﺑﺮاي ﻧﮕﻬﺪاري درازﻣﺪت ژرمﭘﻼﺳﻢ ﮔﻮﻧﻪﻫﺎﯾﯽ اﺳﺖ ﮐﻪ ﺑﻪﺻﻮرت روﯾﺸﯽ ﺗﮑﺜﯿﺮ ﻣﯽﺷﻮﻧﺪ ﯾﺎ ﺑﺬر ﺣﺴﺎس ﺑﻪ ﺧﺸﮑﯽ دارﻧﺪ. در ﺳـﺎل ﻫـﺎي اﺧﯿـﺮ ﭼﻨـﺪﯾﻦ روش ﺣﻔﺎﻇﺖ اﻧﺠﻤـﺎدي ﺑـﺮ اﺳـﺎس ﺷﯿﺸـﻪ اي ﮐـﺮدن ﻣﺤﻠـﻮل درون ﺳـﻠﻮﻟﯽ از ﺟﻤﻠـﻪ ﮐﭙﺴﻮﻟﻪ ﮐﺮدن-ﺷﯿﺸﻪايﮐﺮدن، ﻗﻄﺮهاي-ﺷﯿﺸﻪايﮐﺮدن و اﺳﺘﻔﺎده از ﺻـﻔﺤﺎت اﻧﺠﻤـﺎدي آﻟﻮﻣﯿﻨﯿﻮﻣﯽ )ﻧﻮع V و D( ﺗﻮﺳﻌﻪ ﯾﺎﻓﺘﻪ اﺳﺖ. اﻣـﺮوزه، ﭘﺮﮐـﺎرﺑﺮدﺗﺮﯾﻦ روش ﺣﻔﺎﻇـﺖ اﻧﺠﻤﺎدي، ﮐﭙﺴﻮﻟﻪﮐﺮدن-آبﺑﺮداري اﺳﺖ. در آﯾﻨﺪه؛ ﻓﻨﻮن ﺗﺮﮐﯿﺒـﯽ، ﻧﮕﻬـﺪاري DNA، ﺑﺮرﺳﯽ ﺛﺒﺎت ژﻧﺘﯿﮑﯽ ﮔﻮﻧﻪﻫﺎي ﻣﻨﺠﻤﺪﺷﺪه ﺑﻪوﯾﮋه ﮐﺎﯾﻤﺮﻫـﺎ، اﻧﺠﻤـﺎد درﻣـﺎﻧﯽ و ﯾـﺎﻓﺘﻦ روﯾﮑﺮدﻫﺎي ﺳﺎده، ﻗﺎﺑﻞ اﻋﺘﻤﺎد و ارزان و ﺑﺎززاﯾﯽ راﺣﺖﺗﺮ رﯾﺰﻧﻤﻮﻧﻪﻫﺎي ﻧﮕﻬﺪاريﺷﺪه، ﺑﯿﺸﺘﺮ ﻣﻮرد ﺗﻮﺟﻪ ﻗﺮار ﺧﻮاﻫﻨﺪ ﮔﺮﻓﺖ. ﺑﺮﺧﻼف رﯾﺰازدﯾـﺎدي، ﻣﻄﺎﻟﻌـﻪ ي زﯾـﺎدي روي ﻧﮕﻬﺪاري ژرمﭘﻼﺳﻢ ﮔﯿﺎﻫﺎن زﯾﻨﺘﯽ ﺑﻪوﯾﮋه ﮔﯿﺎﻫﺎن زﯾﻨﺘـﯽ ﮐﻤﯿـﺎب و در ﺣـﺎل اﻧﻘـﺮاض اﻧﺠﺎم ﻧﺸﺪه اﺳﺖ. ﺑﻨﺎﺑﺮاﯾﻦ، ﻫﺪف اﯾﻦ ﻣﻘﺎﻟﻪي ﻣﺮوري، ﺑﺮرﺳﯽ ﻓﻨﻮن ﻣﺨﺘﻠـﻒ ﺣﻔﺎﻇـﺖ درونﺷﯿﺸﻪاي و ﺣﻔﺎﻇﺖ اﻧﺠﻤﺎدي و اﺳﺘﻔﺎده از آﻧﻬﺎ ﺑﺮاي ذﺧﯿـﺮه، اﺻـﻼح و ﻣﺒﺎدﻟـﻪ ي ﻣﻨﺎﺑﻊ ژﻧﺘﯿﮑﯽ ﮔﯿﺎﻫﺎن زﯾﻨﺘﯽ ﺑﻪوﯾﮋه ﮔﯿﺎﻫﺎن زﯾﻨﺘﯽ در ﺣﺎل اﻧﻘﺮاض اﺳﺖ.
چكيده لاتين :
Every year hundreds of new cultivars are produced and introduced. Each ornamental plant is a valuable genetic pool that is used as a source for breeding program. In the last decade there has been an alarming increase in the number of disappearing and dangered species. Several valuable ornamental plants such as Fritillaria imperialis, Buxus hyrcana, Lilium ledebourii, Taxus sempervirens and some orchids are in danger of extinction. Some of these species have medicinal value in addition to aesthetic value. Therefore, the rapid development of approaches to long-term preservation of germplasm of these species under extinction seems to be necessary. Many of these plants are preserved in seed banks or as live plants in natural conditions. These preservation methods are unreliable, hard and costly. Therefore, complementary in vitro approaches represent an important tool for ex situ conservation of plants germplasm. Today, the conservation of ornamentals germplasm can take advantage of innovative techniques which allow preservation in vitro (slow growth storage and cryopreservation) of plant material. Periodic subcultures decrease in slow growth storage. Cryopreservation is the storage of explants at ultra-low temperature (−196°C/−321ºF). At such temperature, all the biological reactions within the cells are hampered; hence the technique makes available the storage of plant material for theoretically unlimited periods of time. Cryopreservation is the only technique currently available for the long-term preservation of the germplasm of plant species that are vegetatively propagated or has recalcitrant seeds. In recent years, some cryopreservation methods based on vitrification of intracellular solution such as encapsulation-vitrification and droplet-vitrification and the use of aluminum cryo-plate (D and V types) have been developed. Today, the encapsulation-dehydration technique is most often used. In the future, combined techniques, DNA conservation, survey of genetic stability of cryopreserved species, especially chimeras, cryotherapy and finding a simple, reliable and inexpensive approach and simpler regeneration of preserved explants will probably be the much popular. Unlike micropropagation, there is not much study on cryopreservation of ornamental plants especially those under danger of extinction and rare. Thus, the aim of this review paper is to evaluate different in vitro conservation and cryopreservation techniques and their use for the storage, breeding and exchange of genetic sources of ornamental plants especially those under the threat of extinction.
