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Ukutshabalalisa izinambuzane ezizibulali-zityalo nge Bt yombona

Imiyalelo: 

Folio strap: Ukutshabalalisa izibulali zezityalo

Byline: NguF.B. Peairs, Colorado State University Ingcali Yesolulo kwezeziNambuzane nongunjingalwazi, kwiinzululwazi zendalo ephilayo kwezolimo kwezolawulo lwezibulali zityalo.

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I-bacillus thuringiensis (Bt) yintsholongwane eyibhaktiriya evelisa iityhefu zezinambuzane. 

Iziqalelo zofuzo (genes) ezivela kwi-Bt zinokufakelwa kwizityalo ezilinywayo ukuze zikwazi ukuvelisa iityhefu zezinambuzane ukuze ke ngoko zimelane nezibulali-zityalo ezithile. 

Imihlanganisela yombona enesiqalelo sofuzo esinye okanye ngaphezulu kwesinye ze-Bt (i-Bt yombona) iyakwazi ukumelana nezinambuzane ezizibulali-zityalo ezithile ezibalulekileyo. 

Imihlanganisela ye-Bt yombona incomeka kakhulu kwaye ilolunye uhlobo ngokoqoqosho olunokusetyenziswa lubolekisane neentlobo ezikhoyo ngoku zokubulala izinambuzane ezizibulali-zityalo, xa ukulawula izinambuzane ezibulala izityalo ekujoliswe kuko kukumanqanaba abalulekileyo ngokoqoqosho.

Ezobugcisa zanamhla zisivumela ukuba siphucule iintlobo zezityalo ngokufakela iziqalelo zofuzo ezivela kwezinye iintlobo. Oku kuluncedo kuba sinako ukwenza imizila ukuba ibolekisane, imizila efana nokumelana kwezinambuzane nonyango, mhlawumbi ezingekhoyo ngokwendalo kwiintlobo ezithile zezityalo, okanye ekunokuba nzima ukuzithutha phakathi kweentlobo zezitylo ngokusebenzisa iindlela zobuchule bokwandisa ngokuhlanganisela izityalo ngendlela eqhelekileyo. 

Omnye wemisebenzi wobu bugcisa banamhla luphuhliso lwemihlanganisela yombona ekwaziyo ukumelana nezinambuzane ezibulala izityalo ezithile ngenxa yokufakelwa kwesiqalelo sofuzo esisuka kwintsholongwane yebhaktiriya yomhlaba oyindalo. Imihlanganisela elolo hlobo yaziwa ngokuba yimihlanganisela “yofuzo oluxananazileyo” (transgenic), nangona ingeyiyo yonke imihlanganisela “yofuzo oluxananazileyo” equlethe imizila yokumelana nezinambuzane.

Nangona le mihlanganisela yofuzo oluxananazileyo lokumelana nezinambuzane ezibulala izityalo inesakhono esincomekayo ekutshatyalalisweni kwezinambuzane ezibulala izityalo, ukusetyenziswa kwazo kwenze iinkxalabo. Uthotho lwembuzo elandelayo neempendulo lunika ingqiqo ebanzi ngale mihlanganisela yombona emelana nezinambuzane nokusetyenziswa kwazo kulawulo lwezinambuzane ezibulala izityalo. 

Yintoni i-Bt? 
I-Bt sisishunqulelo sentsholongwane eyibhaktiriya eqhelekileyo ehlala emhlabeni eyaziwa ngokuba yi-Bacillus thuringiensis. I-Bt ikwabhekiselela kwiimveliso ezitshabalalisa izinambuzane ezenziwa ngezi bhaktiriya.

I-Bt idibene ngantoni nezinambuzane ezibulala izityalo?
Ezinye iintlobo ze-Bt zibulala izinambuzane ngeetyhefu ezibizwa ngokuba ziiprotheyini ezi-insecticidal crystal okanye ii-delta endotoxins. Zaziwa zingenabungozi obungako ebantwini nakwinkoliso yeentlobo ezingezo zibulali-zityalo.

Yintoni i-Bt yombona?
Imveliso yeetyhefu zangaphakathi ze-delta zitshatyalaliswa ngesiqalelo sofuzo esinye kuphela esikwibhaktiriya. Iintlobo ezihlengahlengisiweyo zezi ziqalelo zofuzo zinokubekwa kwizityalo zombona. Izityalo zombona eziqulethe isiqalelo sofuzo zinokuvelisa ityhefu yangaphakathi ye-delta ngoko ke zibe netyhefu kwizinambuzane ezisisisulu ezenza iprotheyini.

Zisetyenziselwa ntoni iziqalelo zofuzo ze-Bt emboneni?
Xa iityhefu zangaphakathi ze-delta zitshiziwe izityalo zaphuka ngokukhawuleza zakuba zisesichengeni sokukhanya kwe-UV. Iityhefu zangaphakathi ze-delta eziveliswe kwisityalo ziyakhuselwa ekukhanyeni kwe-UV. Kwakhona, uninzi lwezinambuzane ezibalulekileyo ezitshabalalisa izityalo kunzima ukuzitshabalalisa kwaye kuduru ngemichiza yokubulala izinambuzane yesiqhelo, kodwa zizizisulu ze-delta endotoxins eziveliswa kwizicwili zezityalo. Kanti ubuchule bobugcisa kwindalo bokufaka ityhefu evelisa isiqalelo zofuzo sebufumaneka.

Ingaba sonke isityalo se-Bt siphelele sinetyhefu?
Kuxhomekekile. Imibandela mibini, sisiganeko nomphumezi, zinto ezo ezitshabalalisa apho iityhefu zangaphakathi ze-delta kwisityalo ziveliswa khona ngokwezixa ezithile. Amaqumrhu embewu ahluka-hlukeneyo asebenzisa iziganeko neziphumezi ezahluka-hlukeneyo, ukuze imihlanganisela yabo yahluke ngokwezicwili zesityalo ezivelisa iityhefu zangaphakathi ze-delta.

Isiganeko sokufaka sisenzo esiphathekayo sokubeka isiqalelo sofuzo se-Bt kwisiseko sofuzo lwesityalo sombona. Kungelo xesha apho indawo esesiqwini ekubekwa kuyo isiqalelo sofuzo lwe-bt ifunyaniswa khona (liphi ityathanga lofuzo futhi ndawoni “chromosomes” njl.njl.) Indawo esikuyo isiqalelo sofuzo seBt ichaphazela indawo apho kuveliswa khona ii-delta endotoxin kwisityalo nendlela ezi tyhefu zangaphakathi ze-delta eziveliswa ngayo. Kwithuba langoku, asinabo ubuchule bobugcisa bokutshabalalisa indawo esikuyo isiqalelo sofuzo se-Bt, ngoko ke isiganeko ngasinye senza ukuba kubekho izityalo ezahlukayo ngendawo apho ziveliswa khona ii-delta endotoxin kananjalo nesixa esiveliswayo.

Umphumezi ngumshukumisi wofuzo oxelela isiqalelo sofuzo se-Bt ukuba ii-delta endotoxins ziveliswe nini kwaye phi. Abaphumezi abahluka-hlukeneyo abaliqela bayafumaneka kwaye ukukhethwa komphumezi nako kuchaphazela apho ziveliswa khona ii-delta endotoxins. Abaphumezi abaliqela abahluka-hlukeneyo bayafumaneka kwaye ukukhethwa komphumezi nako kukwachaphazela isixa se-delta endotoxins eziveliswayo kwisityalo esingumbona, ukuze oko kukhokelele kwiiyantlukwano phakathi kwemihlanganisela.

Zingaphi iintlobo ze-Bt yombona ezikhoyo?
Zininzi iintlobo zemihlanganisela ye-Bt yombona ezikhoyo kwaye ezinye zinokuqulatha isigqobhozi sesikhondo sombona kunye neziganeko zombungu weengcambu zombona. 

Ingaba yonke imihlanganisela yombona inika inqanaba elifanayo lokutshabalalisa?
Inqanaba lokutshabalalisa izibulali-zityalo ekujoliswe kuzo kunye nobubanzi bolawulo obunikwa ngumhlanganisela ngumsebenzi weziganeko oziqulathileyo. Kubhetele ukuthelekisa utshabalaliso lwezinambuzane sisiganeko kunomhlanganiswla. Khetha imihlanganisela eya kusebenza kakuhle kwindawo ohlala kuyo uze ucele iinkcukacha zokutshatyalaliswa kwezinambuzane ezingqale kwiziganeko eziqulethwe yile mihlanganisela.

Ingaba i-Bt yombona iya kusebenza kakuhle kwindawo yam?
Imizila ye-Bt ayifanelanga kuchaphazela ukusebenza komhlanganisela. Ukuba uhlobo olusetyenziswa ngoku lomhlanganisela lusebenza kakuhle, uhlobo lwe-Bt lufanele ukusebenza kakuhle.

Ingaba i-Bt nguwo kuphela umzila ofakwa ngokofuzo emboneni?
Eminye imihlanganisela enemizila efakwe ngokofuzo, efana nokumelana kwemichiza eshabalalisa izibulali-zityalo, ziyafumaneka. Eminye imizila emininzi isaphuhliswa kwaye iya kufumaneka kwixesha elizayo.

Ingaba umbona siso kuphela isityalo esifakwa i-Bt ngokofuzo?
Hayi, ziliqela ezinye izityalo ezihlengahlengisiweyo ukuze zivelise ii-delta endotoxins. Nangona kunjalo, umbona nomqhaphu zenza isixa esikhulu esisetyenziselwa ukuthengisa.

Ingaba zikhona izinto eziluncedo zokusebenzisa i-Bt yombona endaweni yomchiza wokutshabalalisa izinambuzane otshabalalisa izigqobhozi zezikhondo?
I-Bt yombona iya kutshabalalisa impehla yombona ngaphandle kokuchaphazela izidla-nyama nezinye izinambuzane ezifanelekileyo. Oku kufanele ukwenza ulawulo lwezinye izibulali-zityalo ezifana namangolwane ezigcawu lube lula, nangonaa kungekho zinkcukacha zamasimi ukuze kuxhaswe lo mbango.

Ingaba ezi zizinto ezingenaluncedo ngokusebenzisa i-Bt yombon xa kuthelekiswa nolawulo lwempehla yombona?
Kuya kubakho iindleko ezifakelweyo kwimbewu ye-Bt, kungakhathaliseki ukuba lukhon na uhlaselo lwempehla yombona oluchaphazela uqoqosho. Ulawulo olusetyenziswa ngokwesiqhelo ngemichiza lukuvumela ukuba ulinde ubone ukuba uphuhliso lohlaselo luphuhla phambi kokwandisa ulawulo lwezinambuzane na. Kwakhona, ukuthobela iimfuneko zohlangulo (jonga ngezantsi) kunako ukuzenza nzima izenzo zokutyala, ukuvuna nokutshabalalisa izibulali-zityalo

Ingaba ndinako ukutyala iBt yombona ndize ndilibale ngezinambuzane namangolwane?
Hayi, i-Bt yombona ayinakukuvumela ukuba ulibale shici ngezibulali-zityalo eziziziinambuzane. Ukuhlola nokulawula kuyaqhuba ngokuba yimfuneko malunga nezinambuzane ezithile. 

Ingaba zikhona ezinye izinto ezingalunganga ngokusebenzisa i-Bt yombona xa kuthelekiswa nezenzo zokutshabalalisa izibulali-zityalo eziqhelekileyo? 
Kusenokuba khona ubunzima ekuthengiseni i-Bt yombona ejoliswe kwimimandla yentengiso yehlabathi. Imeko yentengiso yehlabathi iguquka ngokukhawuleza, ngoko ke asiyonto ingenakwenzeka ukwazi indlela imithetho eguquka ngayo phakathi kokukhetha umhlanganisela nokuvuna. Le yeyona ngxaki iqhelekileyo malunga neziganeko ezamkelwe kutshanje.

Ingaba i-Bt yombona ndingayisebenzisa phi emsebenzini wam?
I-Bt yombona ifanele ukusetyenziswa kuphela apho umngcipheko wohlaselo lwesibulali-zityalo ekujoliswe kuso uphezulu khona. 

Kwenziwa ntoni ukuthintela ukumelana kwempehla yombona ne-Bt yombona?
Abaphandi kwiiYunivesithi, ishishini lembewu kunye ne-EPA basebenza kunye ukuphuhlisa izicwangciso zolawulo lokumelana ezinamandla nezenzekayo. Zisekwe kumthamo ophezulu nakwizicwangciso zobuchule bokuhlangula.

Yintoni isicwangciso sobuchule bokulangula?
Ukuba isihlangulwa esithile sityalwa nemihlanganisela engena-Bt, ngoko ke nayiphi impehla yombona okanye imibungu yeengcambu ephuma kwezi ndawo iya kuba zizisule ze-Bt. Ziya kudibana nazo naziphi ezisinde kwiBt yombona ukuze zigcine ukuba sisisulu ngokofuzo kwawo onke amanani ephelele. 



