Managing (Maize) 								 Isizulu

Ukuphatha izilokazane emmbileni ngommbila oyiBt

Instructions: 

Folio strap: Ukuphatha izilokazane 

Byline: UF.B. Peairs, waseColorado State University Extension, isazi sesayensi sezilokazane noprofesa wesayensi lezokulima nelokuphatha izilokazane ezidala izifo. 

Create a Fact Box: Amaqiniso ngokushesha … 

Bacillus thuringiensis (Bt) kuyibhaktheriyumi esemhlabathini eyakha ushevu obulala izilokazane. 

Izinhlamvana zemvelo ezitholakala kuBt zingafakwa ezitshalweni zokudla bese zona zithola ikhono lokwakha ushevu obulala izilokazane ezithile, ngakho-ke azisalinywazwa lezo zilokakazane. 

Ummbila oyibhastele onalezi zinhlamvana zeBt azilinywazwa izilokazanane ezivama ukudala ingozi enkulu. 

Ummbila oyibhastela oneBt usebenza kahle ukuvika ingozi yezilokazane, futhi kungenye indlela engabizi imali eningi yokubulala izilokazane. 

Itheknoloji elisha lisivulela indlela ukukhulisa izinhlobo zezitshalo ezinsha ngokungenisa izinhlamvana zemvelo kwezinye izinhlobo zezitshalo. Lokhu kuyasiza ngoba sikwazi ukushintsha ezinye izimpawu zezitshalo bese zizokwazi ukulwa nezinye izilokazane – lokhu kungenzeka kalula ngoba akufani nokukhetha izitshalo eziqinile ngendlela ejwayelekile. 

Okunye okwenzeke kahle kwale theknoloji ensha kumabhastela ommbila akwazi ukulwa nezilokazane ezithile – kufakwa inhlamvana yemvelo emmbileni evela kumabhakteriya atholakala emhlabathini. Amabhastela lawa abizwa ngokuthi "transgenic", kodwa hhayi onke lawa akwazi ukulwa nezilokazane.

Nokho lamabhastela akwazi ukulwa nezilokazane, kukhona imibuzo efanele ibuzwe ngoba abanye abantu bayakusola lokhu: 

IBt kuyini? 
IBt lisho ngokumfusha ibhaktheriya elisemhlabathini elibizwa ngokuthi Bacillus thuringiensis. IBt lisho futhi umuthi obulala izilokozane owenzwe ngala mabhaktheriya.

Uyini umsebenzi weBt maqondana nezifo zezilokazane? 
Ezinye izinhlobo zeBt zibulala izilokazane ngamathoksini abizwa ngokuthi insecticidal crystal proteins noma delta endotoxins. Amathoksini avama ukungadali ingozi kubantu nakuzinye izilokazane ezingalethi izifo.

Ummbila oyiBt uyini? 
Ukukhulisa ama-delta endotoxin kuphathwa yinhlamvana yemvelo eyodwa ephakathi kula mabhaktheriya. Izinhlobo ezishintshiwe zingafakwa esitshalweni sommbila. Isitshalo sommbila esinayo leyo nhlamvana yemvelo siyakwazi ukwakha ama-delta endotoxin bese ona azobulala izilokazane ezingazwani ngaleyo nhlobo yephrothiyini. 
 
Kungani sisebenzise izinhlamvana zemvelo esinguBt emmbileni? 
Ama-Delta endothoksini afafazwa ngaphezu kwezitshalo avama ukulahlekelwa amandla ngenxa ukukhanya okubizwa ngokuthi iUV light. Kodwa ama-Delta endotoxin awakhiwa ngaphakathi kwesitshalo awalinyazwa iUV light. Futhi eziningi izifo ezidalwa yizilokazane ziyinkinga ukuphatha, kuyadula ukuzibulala ngomuthi okhona ojwayelekile, kodwa zingabulawa ngamadelta endotoxin akhiwa ngaphakathi kwesitshalo. Futhi likhona itheknoloji lokufaka lelo thoksini elidala inhlamvana yemvelo elenza.

Isitshalo sonke sommbila esineBt sinamathoksini na? 
Kuzoya ngokwenzekayo. Kukhona izinto ezimbili eziphatha ukuthi amadelta endothoksini akhiwa kuphi esitshalweni: indlela akhiwa ngayo naloyo oqala umsebenzi wokwakha. Izinkampani ezikhulisa izimbewu zisebenzisa izindlela ezahlukene zokwakha amadelta endothoksini ngakho-ke izinhlobo zamabhastela azo azohluka futhi.

Okwenzekayo ngulokhu: inhlamvana (gene) yeBt ifakwa ezintweni zemvelo (genetic material) zesitshalo. Lokhu kukhombisa indawo lapho inhlanvana yeBt ingena khona (kuliphi ikhromosomi nakuyiphi indawo kwalelo khromosomi, njll). Indawo lapho inhlamvana ifakwa khona esitshalweni izokhombisa ukuthi ama-endothoksini akhiwa kuphi futhi kuzokwakhiwa inani elingakanani. Ngokwamanje itheknoloji alivumi ukuphatha indawo lapho inhlamvana yeBt ingena khona, kanjalo-ke ukufakwa kwale nhlamvana kuyahluka njalo bese kutholakala izitshalo ezahlukile futhi zakha inani lama-endothoksini elihlukile.

Into eqala lo msebenzi ifana neswitshi elitshela inhlamvana yeBt ukuqala nini nokuqala kuphi ukwakha ama-endothoksini. Kukhona eziningi izinto ezikwazi ukuqala lo msebenzi futhi ziyahluka ngendlela zisebenza ngayo, ngakho-ke into ethile izokwakha ama-endothoksini endaweni ethile nangenani elithile, bese kutholakala amabhastela ahlukile.

Kukhona izinhlobo ezingakanani zommbila oneBt? 
Kukhona izinhlobonhlobo zamabhastela aneBt, ezinye zikwazi ukuvimba isilokazane esiqopha izinkuni naleso esiqopha izimpande. 

Onke amabhastela aneBt asebenza ngokufana na? 
Ukuphatha izilokazane ezithile kuhambelana nenani lezinto eziqala lo msebenzi ezifakwe kubhastela elithile. Khetha ibhastela elinezinto zokuqala lo msebenzi elifanele indawo lapho ulima khona – buza ukuthi ibhastela elithile lizokwazi ukuphatha izilokazane ezihlupha kakhulu endaweni yakho.

Ummbila oneBt uzosebenza kahle endaweni lapho ngilima khona? 
Izinto zeBt azingeke zihluphe ukumila kwamabhastela. Uma ibhastela elijwayelekile limila kahle endaweni yakho, nalelo elineBt lizomila kahle futhi

IBt liyinto eyodwa efakwa ezintweni zemvelo zommbila (genetically engineered) na? 
Kukhona amanye amabhastela anokunye okufakiwe, njengokungabulawa ngumuthi obulala ukhula. Kukhona izinto ezinye ezisahlolwa, mhlawumbe zizotholakala ngesikhathi esizayo.

Ummbila uyisitshalo esodwa esifakwa ngeBt? 
Qha, kukhona izitshalo eziningi ezishintshiwe ukwakha ama-endothoksini. Kodwa ummbila nokhothini usetshenziswa kakhulu ngale ndlela.

Kukhona usizo olunye lokusebenzisa iBt ngaphandle kokuvimba isilokazane esiqopha izinkuni zommbila? 
Ummbila oneBt uvimba isilokazane esiqopha izinkuni zommbila kodwa awubulali ezinye izilokazane ezingaba nosizo. Lokhu kwenza ukuthi kubelula ukuphatha ezinye izifo njengozibungu zolwembu.

Kukhona okubi okungenzeka lapho sisebenzisa ummbila oneBt uma sikulinganisa nendlela ejwayelekile yokubulala isilokazane esiqopha izinkuni zommbila? 
Izimbewu zommbila ezineBt zidula ukudlula ezinye. Ungazitshala noma ungazi ukuthi zikhona noma zingekho lezo zilokazane. Ukuphatha ngamakhemikeli kukunikeza isikhathi sokubona ukuthi zikhona lezo zilokazane, lapho zivela ungakhokha imali ukuzibulala. Futhi ukulandela izidingo zesiphephelo (refuge requirements (bheka phansi)) kungenza ukuthi ukutshala nokuvuna kungaba nzima.

Ngingatshala ummbila oneBt bese ngikhohlwe izilokazane nezibungu? 
Qha, ummbila oneBt awukwazi ukwenza ukuthi ukhohlwe inkinga yalezi zifo. Kukhona ezinye ezifanele zihlolwe ziphathwe njalo. 

Kukhona okunye okubi okungenzeka lapho sisebenzisa ummbila oneBt uma sikulinganisa nendlela ejwayelekile yokuphatha izilokazane? 
Kungaba khona inkinga ukumaketha ummbila oneBt, kakhulukazi ummbila othengiswa phesheya. Kodwa imakethe emhlabeni jikelele ishintsha njalo, asazi ukuthi imilayezo maqondana namabhastela izothini kusasa. Lokhu kuyinkinga kuphela lapho kungeniswa into ensha enza lo msebenzi esitshalweni.

Ngizowusebenzisa kuphi ummbila oneBt ekulimeni kwami? 
Ummbila oneBt ufanele usetshenziswe kuphela ezindaweni lapho ingozi yezilokazane inkulu. 

Kwenzekani ukuvimba ukuthi isilokazane esiqopha izinkuni zommbila siqala ukwejwayela ummbila oneBt bese asifi? 
Abahloli kumanyuvesiti, ibhizinisi elikhiqiza izimbewu neEPA bonke besebenzana ukuthola amasu azokuvimba lokhu. Lokhu kuhambelana futhi nezidingo zesiphephelo nezindlela zokuzisebenzisa.

Isu lesiphephiso kuyini (refuge strategy)? 
Uma indawo ethile (isiphephiso) itshalwa ngommbila ongeneBt, izilokazane ezivela kuleyondawo zizokufa lapho zihlangana nommbila oneBt. Zona zizomatana nalezo ezithole amandla ukulwa neBt bese izizukulwane zazo zizophinda zife uma zithintana nommbila oneBt. 

