Kuyini polyploidy? Iyiphi indima ifeza okukhethiwe futhi ngokwemvelo

Ngemva kokufunda lesi sihloko, uzofunda ukuthi polyploidy. Sizobheka indima oyifezayo. Uyofunda yiziphi izinhlobo polyploidy.

polyploids Ezemfundo

Okokuqala, usitshele ukuthi kushiwoni leligama engaqondakali. Amaseli noma abantu nge engaphezu kwemibili amasethi wama-chromosomes abizwa ngokuthi polyploids. amaseli Polyploid nge imvamisa low zibangelwa "amaphutha" mitosis. Lokhu kwenzeka uma chromosome zihlukaniswe, futhi cytokinesis kwenzeka. Ngakho kungenzeka amaseli kumiswa kabili inani lezakhi zofuzo (diploids). Uma edabula interphase, uzokwabelana nabo, kungaba zisenza sibe (ezocansi noma asexually) ngabanye entsha kabani amaseli kuyodingeka Ama-chromosomes e kabili njengoba ningi kunabazali bazo. Ngakho, inqubo ukwakheka - okungukuthi polyploidy. izitshalo Polyploid zingaba eyayenziwe usebenzisa colchicine - alkaloid abacindezela kumiswa uthi lokuphotha mitotic ngu kuwukwephula microtubule kumiswa.

izakhiwo polyploids

ngokuvamile Lezi zitshalo simo esishubile iyincane kakhulu kunaleyo diploid ezihlobene, ngoba isakhi ngasinye imelelwa kubo okungenani kabili inombolo. Lapho cleavage we homozygous siyinzalo kwamanye esikhubazayo isakhi sofuzo abantu bakha kuphela 1/16 esikhundleni 1/4 e diploids. (Kuzo zombili lezi zimo kucatshangwa ukuthi ukuvama alleles esikhubazayo kuyinto 0.50.) Polyploidy selfing eyinqaba, zokuqhubeka nokwehlisa simo esishubile yabo, naphezu kweqiniso lokuthi diploids zabo ahlobene advantageously isiphambano impova.

Lapho kukhona polyploids

Ngakho, siye waphendula umbuzo, yini polyploidy. Kodwa lapho kukhona izitshalo ezifana?

Ezinye polyploids zingcono bazivumelanisa ezindaweni ezomile noma okushisa aphansi ukwedlula owaqalwa diploid, kuyilapho abanye ezisilungele kangcono ezithile inhlabathi. Ngenxa yalokhu, bangakwazi axazulule izindawo izimo ezimbi kakhulu khona, lapho okhokho babo diploid cishe ngabe sesafa. Nge imvamisa elincane zenzeka kwemiphakathi eminingi engokwemvelo. Ziyakwazi lemelula kakhulu kunaloko diploids ohambelana, beze outbreeding. Kulokhu, njengoba nje ingase ivezwe nzalo evundile. Ngaphansi polyploids hybrid imvelaphi ezakhiwe kuphindaphindwe kabili inani lezakhi zofuzo a nzalo diploid oyinyumba. Lena enye yezindlela plodovistosti yokutakula.

Icala lokuqala olubhaliwe polyploidy

Ngakho-ke, ngaphansi ezivamile, ngo nzalo polyploid obakhiwa radishes kanye iklabishi. Lokhu kwakunjalo lokuqala ezabhalwa ka polyploidy. Bobabili izizukulwane siwuhlobo ka crucifers futhi ahlobene eduze. Ngo amaseli ukuphathwa kwabathintwayo , futhi zombili izinhlobo Ama-chromosomes e kuyinto 18, kanti metaphase lokuqala meiotic 9 njalo Kutholwe ngazimbili lezakhi zofuzo. Nge ebunzimeni obuthile, lalo laliqongelelwe hybrid phakathi kwalezi izitshalo. Ngo meiosis, kwakudingeka 18 Ama-chromosomes e ayibhangqiwe (9 futhi 9 kusukela isithombo kusuka iklabishi) futhi ngokuphelele oyinyumba. Phakathi kwalezi izitshalo hybrid polyploidy angesabi kwakhiwa, lapho kumaseli ukuphathwa kwabathintwayo kwaba Ama-chromosomes e-36 ngesikhathi meiosis futhi njalo kwakhiwa ngazimbili 18. Ngamanye amazwi, hybrid polyploid kwadingeka zonke Ama-chromosomes e-18 njengoba isithombo, futhi iklabishi futhi esebenza kahle. Lokhu hybrid kwakuhluke kakhulu kwande.

Polyploids-ukhula

kuphakama Ezinye polyploids like ukhula ensimini ezenziwa abantu, futhi ngezinye izikhathi baye baphumelela nokuchuma okuphawulekayo. Esinye isibonelo owaziwa - abakhileyo emaxhaphozini usawoti bohlobo lwe-Spartina. Olunye uhlobo, S. maritima (ngezansi), itholakala emaxhaphozini kanye emikhawulweni eYurophu nase-Afrika. Olunye uhlobo, S. alterniflora, wethulwa UK empumalanga eNyakatho neMelika emhlabeni 1800 futhi kamuva, lusakazwe kabanzi, ukwakha koloni elikhulu lendawo.

kakolweni

Enye yezindlela ezibaluleke kakhulu amaqembu isitshalo polyploid angabhekwa uhlobo kakolweni Triticum (ngezansi). Okuvame kakhulu isivuno okusanhlamvu emhlabeni - kakolweni ezithambile (T. aestivum) - has 2N = 42. Soft kakolweni umsuka okungenani iminyaka engu-8,000 edlule, cishe eYurophu Ephakathi, ngenxa hybridization zemvelo kakolweni kutshalwa, eye 2N = 28, nge cereal zasendle uhlobo olufanayo ukuthi babe 2N = 14. utshani Wild, cishe wakhula like ukhula phakathi kukakolweni. Hybridization, emenza kakolweni elithambile, kungavela phakathi polyploidy livela ngezikhathi ezithile e imiphakathi yamazwe kokubili zinhlobo sabazali.

Kungenzeka ukuthi ngokushesha nje lapho kakolweni 42-chromosome ngezibonakaliso zayo eziwusizo kwavela eziseceleni abalimi yokuqala, masinyane wakuphawula futhi ekhethiwe ukulima olwengeziwe. Omunye amafomu wakhe sabazali, 28-chromosome kakolweni kutshalwa, kwaba nomphumela hybridization of zinhlobo ezimbili zasendle chromosome 14 ezivela eMpumalanga Ephakathi. Izinhlobo kakolweni, nge 2N = 28, futhi manje uqhubeke kudingeka sihlakulelwe kanye 42-chromosome. Okunjalo kakolweni chromosome 28 luwumthombo oyinhloko yokusanhlamvu ukwenziwa pasta ngenxa adhesiveness okusezingeni eliphezulu amaprotheni. Lapha nendima eyadlalwa polyploidy.

Triticosecale

Ucwaningo lwamuva luye lwabonisa ukuthi imigqa emisha etholwe hybridization angathuthukisa ukukhiqiza kwezolimo. Polyploidy e zokuzalanisa izitshalo isetshenziswa kabanzi kakhulu. ethembisa ngokukhethekile Triticosecale - iqembu hybrid manmade phakathi kakolweni (Triticum) kanye rye (Secale). Ezinye zazo, ngokuhlanganisa isivuno kakolweni rye mazombezombe, esitebeleni kunazo nokugqwala komugqa - isifo, owabangela umonakalo omkhulu kwezolimo. Lezi izindawo ezibalulekile ikakhulukazi eziphakeme izifunda ezindaweni ezishisayo futhi ezisondelene nazo, lapho nokugqwala - main isici nokukhawulela ukutshala ukolo. manje Triticosecale Simila ngezinga elikhulu futhi lithandwa kakhulu eFrance nakwamanye amazwe. Isenzakalo esidume kunazo zonke umugqa 42-chromosome lokhu wokudla. Kwakuthinta etholwe kuphindaphindwe kabili inani lezakhi zofuzo ngemva hybridization chromosome 28 rye Ukolweni 14-chromosomal.

Izinhlobonhlobo polyploids

Emvelweni, ezithathwe ngaphansi kwethonya kwezimo zangaphandle, hhayi ngenxa yezenzo zesintu. Umbala wawo - omunye izindlela ezibaluleke kakhulu kwemvelo. Namuhla abaningi polyploid amelwe flora emhlabeni (ngaphezu kwesigamu wonke zezimila). Phakathi kwabo kukhona abaningi izitshalo ezibaluleke kakhulu - hhayi kuphela ukolweni, kodwa futhi ukotini, umoba, ubhanana, amazambane kanye sunflower. Ukuze lolu hlu kungenziwa wanezela enhle kunazo engadini izimbali - Chrysanthemums, pansies, dahlia.

Manje ngoba sewuyazi ukuthi lokho polyploidy. Indima yowesifazane kwezolimo, njengoba ungabona, kuphezulu kakhulu.