Biofortifikacija – važan deo poljoprivredne proizvodnje

Abstract

Biofortifikacija predstavlja čitav kompleks mera koje obuhvataju selekcionisanje novih genotipova, manipulacije genima, različite mere gajenja kojima se omogućava bolja apsorpcija i povećana akumulacija esencijalnih elemenata, kao što su gvožđe, cink, mangan, bakar i dr. u jestivim delovima gajenih biljaka. Pored toga, nezaobilazni deo biofortifikacije predstavlja i unapređenje faktora koji povećavaju apsorpciju mikroelemenata, a eliminisanje faktora koji ometaju njihovu apsorpciju i time smanjenje antinutritiva. Rezultati su pokazali da je u semenu linija koje pripadaju Lankaster heterotiĉnoj grupi povećanje sadrţaja Zn bilo praćeno padom fitata, dok veći sadrţaj β-karotena u semenu BSSS genotipova može poboljšati apsoprpciju Mn i Zn. Neke linije kukuruza iz Banke gena imaju povećanu pristupačnost Mg, Fe, Mn i Zn, zahvaljujući nižem odnosu fitat/β-karoten i mogle bi se iskoristiti u selekciji fortifikovanih hibrida kukuruza. U semenu nekih populacija, variranje u sadržaju Fe i Zn je nezavisno od inhibitora i promotera. Održiva proizvodnja koja obuhvata kombinovane ili pokrovne useve može da poboljša apsorpciju i akumulaciju esencijalnih elemenata u zrnu kukuruza i soje. Tako, u zrnu soje gajene u kombinaciji s kukuruzom, β-karoten je osnovni faktor koji doprinosi Fe pristupačnosti. Naizmenični redovi u kombinaciji s bio-đubrivom doprinose povećanoj Fe i Mg pristupačnosti, kao i boljem iskorišćenju uslova, povećavajući plodnost zemljišta soje i kukuruza. U eksperimentima s pokrovnim usevima, kombinacija organskog malča i bio-đubriva se pokazala kao najefikasnija za poboljšanu pristupačnost Mg i Zn iz zrna kukuruza šećerca, dok su stočni grašak i ozimi ovas najefikasnija kombinacija za poboljšanu Fe pristupačnost. Određena bio- i organska đubriva mogu povećati nivo β-karotena, a smanjiti nivo fitata u zrnu kukuruza, povećavajući pristupačnost esencijalnih elemenata.

Biofortification represents complex of different measures that include new genotypes breeding, gene manipulations, different cropping measures which enable better absorption and accumulation of essential elements, like iron, zinc, manganese, copper, etc. in edible plant parts. Besides, increase in factors that promote microelements absorption, as well as reduction in antinutritives (factors that supress microelements absorption) represent unavoidable part of biofortification. Results showed that Zn increase is followed by reduction in phytate content, particularly in maize lines from Lancaster heterotic group, while increased β-carotene content could improve Mn and Zn availability from grain of BSSS genotypes. Some maize lines from Gene bank were characterised with increased Mg, Fe, Mn and Zn availability, owing to low phytate/β-carotene ratio. They could be used in breeding for production of fortified maize hybrids. In grain of some landraces, variations in Fe and Zn content are independent of variations in inhibitor and promoter contents. Sustainable practices, like intercropping or application of cover crops could improve absorption and accumulation of essential elements in maize and soybean grain. For instance, in grain of intercropped soybean β-carotene is the main factor contributing to Fe availability. Alternating rows in combination with biofertilizer emphasised increased Fe and Mg availability and better utilization of the conditions and the soil fertility under the both, maize and soybean. In experiments with cover crops, organic mulch+biofertilizer expressed the highest efficiency for improved Mg and Zn bioavailability from sweet maize kernel, while field pea+winter oats was the most effective for improved Fe bioavailability. Some biofertilizers and organic fertilizers could increase β-carotene level and decrease phytate concetration in maize grain, thus increasing bioavailability of essential elements.