Biyoekonomi ile bitki \u2013 hayvan ve di\u011fer canl\u0131lar\u0131n ara\u015ft\u0131rma, geli\u015ftirme, \u00fcretim ve kullan\u0131m\u0131 i\u00e7in art\u0131 de\u011ferler \u00fcretilerek ekonomik kazan\u00e7 sa\u011flanmas\u0131 hedeflenmektedir. Ayn\u0131 yakla\u015f\u0131mla tar\u0131m da, art\u0131 de\u011ferlere ula\u015fmak i\u00e7in yo\u011fun ara\u015ft\u0131rma yat\u0131r\u0131mlar\u0131na gereksinim duyar. G\u00fcn\u00fcm\u00fczde \u00f6zellikle n\u00fcfus art\u0131\u015f\u0131, g\u0131da krizi, k\u00fcresel \u0131s\u0131nma gibi nedenlerle, birim \u00fcniteden maksimum verimin sa\u011flanma konusu \u00f6ne \u00e7\u0131kmaktad\u0131r. Gerek bitki ve gerekse hayvan \u0131slah\u0131 ile bug\u00fcne kadar g\u00f6r\u00fclmemi\u015f performansta yeni genotiplere ula\u015f\u0131lm\u0131\u015ft\u0131r. \u00d6rne\u011fin, bir dekardan 2,24 ton [1] \u00e7eltik hasad\u0131na olanak verecek \u00e7e\u015fitlerin \u0131slah\u0131 gibi (T\u00fcrkiye\u2019de \u00e7eltik verimi 0,8 ton\/da). Gelecekte geli\u015ftirilecek yeni \u00e7e\u015fitler bu s\u0131n\u0131rlar\u0131 da zorlayacakt\u0131r. Asl\u0131nda yar\u0131n\u0131n g\u0131da gereksinimi i\u00e7in, ekim alanlar\u0131 de\u011fi\u015fmese dahi (azalaca\u011f\u0131 beklenmektedir), her \u00fcr\u00fcn i\u00e7in verimin s\u00fcrekli art\u0131r\u0131lmas\u0131 zorunlu g\u00f6r\u00fcnmektedir. O nedenle GEN\u2019e yat\u0131r\u0131m karl\u0131 bir yat\u0131r\u0131m olman\u0131n \u00f6tesinde stratejik bir yat\u0131r\u0131md\u0131r [2].<\/p>\n
Yeni \u00e7e\u015fitlerin geli\u015ftirilmesi bitki \u0131slah\u0131 ile sa\u011flanm\u0131\u015ft\u0131r. Seleksiyonlar\u0131n ba\u015far\u0131lar\u0131 s\u0131n\u0131rland\u0131\u011f\u0131nda, yapay pop\u00fclasyonlara gereksinim duyulmu\u015f ve melezlemelerle kromozom aktarmalar\u0131 ba\u015flam\u0131\u015ft\u0131r. 1910\u2019larda H\u0130BR\u0130T G\u00dcC\u00dc veya MELEZ AZMANLI\u011eI gibi performans art\u0131\u015flar\u0131 sa\u011flanmaya ba\u015flanm\u0131\u015ft\u0131r. Bu evrede, t\u00fcr i\u00e7i ve t\u00fcrler aras\u0131 melezlemelerle \u201cYE\u015e\u0130L DEVR\u0130M [3]\u201d ger\u00e7ekle\u015ftirilmi\u015ftir. Salt bitki boyu k\u0131salt\u0131larak daha fazla verim sa\u011flanm\u0131\u015f ve b\u00f6ylece 1990\u2019larda ikiye katlanan d\u00fcnya n\u00fcfusunun g\u0131da gereksinimi kar\u015f\u0131lanm\u0131\u015ft\u0131r.<\/p>\n
Genelde bir \u00e7e\u015fidin \u0131slah\u0131 i\u00e7in 12-15 generasyon (bir y\u0131lda iki, \u00fc\u00e7 generasyon \u00fcretilebilir) gibi s\u00fcre gerekmektedir. 1940\u2019larda ba\u015flat\u0131lan mutasyon \u0131slah\u0131nda ise tek gende kal\u0131tsal de\u011fi\u015fim hedeflenmi\u015f ve bug\u00fcne dek 3000 civar\u0131nda yeni genotip tescil edilerek tar\u0131ma kazand\u0131r\u0131lm\u0131\u015ft\u0131r.<\/p>\n
AB\u2019de bitki \u0131slah\u0131n\u0131n sosyal, ekonomik ve \u00e7evresel katk\u0131lar\u0131n\u0131n neler oldu\u011funu saptamaya y\u00f6nelik bir ara\u015ft\u0131rmada [4], 2000-2013 y\u0131llar\u0131 aras\u0131nda bitkisel \u00fcretimde verimin %16 artt\u0131\u011f\u0131 ortaya \u00e7\u0131km\u0131\u015ft\u0131r. Verim art\u0131\u015f\u0131nda ila\u00e7, g\u00fcbre, tohum ve di\u011fer girdilerin toplu kullan\u0131m\u0131 etkili olmu\u015ftur. Fakat bitki \u0131slah\u0131 ile geli\u015ftirilen yeni \u00e7e\u015fitlerin; yani tohumun; verim art\u0131\u015f\u0131ndaki pay\u0131n\u0131n %60 \u2013 80 oran\u0131nda oldu\u011fu tahmin edilmektedir. S\u00f6z konusu bu ara\u015ft\u0131rmaya g\u00f6re, baz\u0131 bitkilerin \u0131slah\u0131 ile y\u0131ll\u0131k %2,5\u2019lara (\u015feker pancar\u0131) varan bir art\u0131\u015f sa\u011flanmas\u0131 olduk\u00e7a \u00e7arp\u0131c\u0131d\u0131r. 1990\u2019larda ba\u015flayan gen aktar\u0131mlar\u0131 ile gelen GDO\u2019lar, her y\u0131l i\u015flenen d\u00fcnya tar\u0131m arazilerinin %13\u2019\u00fcnde ekilmektedir. 2010\u2019lara gelindi\u011finde ise, gen aktarmaya gerek kalmaks\u0131z\u0131n, genom i\u00e7i d\u00fczenlemelerle yeni genotipler elde e dilmeye ba\u015flanm\u0131\u015ft\u0131r.<\/p>\n
Yeni bitki \u0131slah teknikleri (YBIT) diye de tan\u0131mlanan bu genom d\u00fczenlemeleri bir seri yeni gen m\u00fchendisli\u011fi y\u00f6ntemlerini kapsamaktad\u0131r. Testbiotech Factsheet 22-1-2015 [5]’e g\u00f6re bu y\u00f6ntemler \u201ctilling, protoplast fusion, cisgenesis, oligonucleotide techniques, CRISPR-Cas, ZEN, TALEN, zinc finger nucleases, meganucleases ve epigenetics\u201d ba\u015fl\u0131klar\u0131 alt\u0131nda toplanmaktad\u0131r. Fakat bunlardan \u201cCRISPR-Cas\u201d \u00fcst\u00fcnde en \u00e7ok durulan kategoridir. Bu y\u00f6ntemlerde, GDO\u2019lardaki gibi d\u0131\u015far\u0131dan herhangi bir gen transferi s\u00f6z konusu de\u011fildir. Tersine, hedeflenen genin, i\u015flem a\u015famas\u0131nda uygulanan ge\u00e7ici DNA kesici enzimler yard\u0131m\u0131 ile susturulmas\u0131, etkisinin art\u0131r\u0131l\u0131p azalt\u0131lmas\u0131, mikro-mutasyona tabi tutulmas\u0131 gibi genom i\u00e7i uygulamalarla yeni genotipler yarat\u0131lm\u0131\u015f oluyor. Do\u011fal olarak bu y\u00f6ntemler gen haritalar\u0131 \u00e7\u0131kart\u0131lan bitkilerde uygulanabilirler.<\/p>\n
S\u00f6z konusu YBIT, di\u011fer bitki \u0131slah y\u00f6ntemlerine g\u00f6re ucuz ve zaman kazand\u0131r\u0131c\u0131d\u0131r. Nitekim daha \u015fimdiden k\u00fc\u00e7\u00fck bir Kaliforniya \u015firketi, yabanc\u0131 ot ilac\u0131na dayan\u0131kl\u0131 kolza \u00e7e\u015fidini, ABD ve Kanada\u2019da pazarlamak \u00fczere tescil ettirmi\u015ftir. \u00c7in\u2019de k\u00fcllemeye dayan\u0131kl\u0131 bu\u011fday, Japonya\u2019da raf \u00f6mr\u00fc uzat\u0131lm\u0131\u015f domates, Birle\u015fik Krall\u0131k\u2019ta dormansi sorunu \u00e7\u00f6z\u00fclm\u00fc\u015f arpa genotipleri de yine CRISPR y\u00f6nteminin yeni \u00fcr\u00fcnleri olarak yak\u0131nda pazara girebilecektir. Ayn\u0131 y\u00f6ntemin Birle\u015fik Krall\u0131k\u2019ta hayvan \u0131slah\u0131nda da kullan\u0131ld\u0131\u011f\u0131 ve boynuzsuz s\u0131\u011f\u0131r \u0131slah \u00e7al\u0131\u015fmalar\u0131n\u0131n k\u0131sa zamanda sonu\u00e7lanaca\u011f\u0131 beklenmektedir.<\/p>\n
GDO\u2019ya kar\u015f\u0131 olan AB\u2019de, bu teknikler tohum sekt\u00f6r\u00fcn\u00fcn dikkatini \u00e7ekti. Ve \u015fu anda, d\u00fcnyadaki YBIT ile ilgili ara\u015ft\u0131rmalar\u0131n %46\u2019s\u0131 AB kaynakl\u0131. Ne var ki bu teknikle geli\u015ftirilen \u00e7e\u015fitlerin tescili, GDO\u2019lar\u0131 da kapsayan y\u00f6nerge ile ayn\u0131 kategoridedir (Directive 2001\/18\/EU). Ger\u00e7ekten de s\u00f6z konusu biyog\u00fcvenlik mevzuat\u0131na g\u00f6re \u201cgeleneksel y\u00f6ntemler d\u0131\u015f\u0131nda, modern gen m\u00fchendisli\u011fi y\u00f6ntemleri ile geli\u015ftirilmesi\u201d nedeniyle GDO ve YBIT \u00fcr\u00fcnlerinin tescili farks\u0131zd\u0131r. Halbuki 2000\u2019li y\u0131llarda devreye giren bu y\u00f6nerge, bitkinin kendi genomu i\u00e7inde yap\u0131lan gen m\u00fchendisli\u011fi uygulama ve bulgular\u0131ndan \u00f6nce \u00e7\u0131kar\u0131lm\u0131\u015ft\u0131.<\/p>\n
Durum AB\u2019nin yetkili organlar\u0131nda de\u011ferlendirilmektedir. Fakat YBIT ve GDO hala ayn\u0131 kefeye kondu\u011fu takdirde, bundan AB tohum sekt\u00f6r\u00fc \u00e7ok zarar g\u00f6recektir. \u00c7\u00fcnk\u00fc bir\u00e7ok risk analizi gerektiren GDO\u2019lu \u00e7e\u015fit adaylar\u0131n\u0131n tescil masraflar\u0131, onlarca milyonluk b\u00fct\u00e7eler gerektirmektedir ve \u015fu anda YBIT\u2019i kullanan AB firmalar\u0131n\u0131n %90\u2019\u0131 KOB\u0130, yani s\u00f6z konusu tescil masraflar\u0131n\u0131 kald\u0131ramayacak k\u00fc\u00e7\u00fck i\u015fletmelerden olu\u015fmaktad\u0131r. O nedenle, e\u011fer YBIT i\u00e7in ayr\u0131 bir y\u00f6nerge \u00e7\u0131kar\u0131lmad\u0131\u011f\u0131 takdirde bundan, yaln\u0131z k\u00fc\u00e7\u00fck tohumculuk kurulu\u015flar\u0131n\u0131n rekabet g\u00fc\u00e7leri olumsuz etkilenmekle kalmayacak, yenilik\u00e7i bilim bundan darbe alacakt\u0131r!<\/p>\n
[1]A\u00e7\u0131kg\u00f6z N. 2013: \u00c7ELT\u0130K VER\u0130M\u0130NDE DEKARA 2,24 TONLUK D\u00dcNYA REKORU http:\/\/bit.ly\/1UBBrYA
\n[2] http:\/\/bit.ly\/1UTYIol
\n[3]1960\u2019larda Nobel \u00f6d\u00fcll\u00fc Dr. Bourlogh ve ekibi bu\u011fday ve \u00e7eltikte bitki \u0131slah\u0131 bitki boyunu k\u0131saltarak sa\u011flad\u0131klar\u0131 verim art\u0131\u015f\u0131 ile ikiye katlanan d\u00fcnya n\u00fcfusunun g\u0131da gereksiniminin kar\u015f\u0131lanmas\u0131n\u0131 sa\u011flam\u0131\u015flard\u0131r.
\n[4] http:\/\/bit.ly\/1Uq6m9w
\n[5] http:\/\/bit.ly\/1fJLKrJ<\/p>\n
<\/p>\n