Variability of factors that affect availability of iron, manganese and zinc in maize lines

Abstract

Deficiencies of some mineral elements are causing serious health problems, which could be prevented by increase of mineral nutrients in food with supplementation, food fortification or plant breeding. From this point, experiment with 78 maize inbred lines was set up to determine maize lines with improved contents of Fe, Zn and Mn, as well as their relations with phytic acid, inorganic phosphorus and β-carotene, as factors which affect their absorption. Obtained results suggest that investigated maize lines show high variability in concentration of Fe, Mn and Zn, as well as phytic acid (which sustain availability of mineral elements) and β-carotene (which enables better absorption of mineral element and minimize negative effect of phytic acid). From this point of view, group of genotypes with phytic P ≤ 3 g kg-1 was interesting. Among them, L2 and L23 are maize lines with relatively high inorganic P, Fe and Zn contents, and together with relatively low ratio between phytic and inorganic P, they could be used as a good source of P, Fe and Zn. On the other hand, L1 and L4 are also maize lines with high inorganic P, β-carotene and Mn, and favourable ratio between phytic acid and Fe and Zn, what could give them advance as source of Mn in breeding programs. The same maize lines could also be candidates with improved ability for Fe and Zn absorption, what is based on high β-carotene content. Maize line L14, with relatively high concentration of all three.

Nedostatak pojedinih mineralnih elemenata može dovesti do ozbiljnih zdravstvenih problema koji se mogu sprečiti povećanjem sadržaja minerala u ishrani preko suplemenata, fortifikacijom hrane ili oplemenjivanjem biljaka. Sa te tačke gledišta, postavljen je eksperiment sa 78 samooplodnih linija kukuruza, kako bi se odredile linije sa poboljšanim sadržajem Fe, Zn i Mn, kao i njihove relacije sa fitinskom kiselinom, neorganskim fosforom i β-karotenom, kao faktorima koji utiču na njihovu apsrpciju. Dobijeni rezultati ukazuju na visoku varijabilnost isipitivanih linija u pogledu koncentracije Fe, Mn i Zn, kao i fitrinske kiseline (koja smanjuje pristupačnost mineralnih elemenata) i β-karotena (koji omogućava bolju apsorpciju mineralnih elemenata i minimizira negativan uticaj fitiske kiseline). Sa te tačke gledišta, grupa genotipova sa fitinskim P ≤ 3 g kg-1 je bila izdvojena. Od njih, L2 i L23 su linije kukuruza sa relatvno visokim sadržajem neorganskog P, Fe i Zn, što sa relatvno niskim odnosom između fitinskog i neorganskog P upućuje da bi mogle biti izvor P, Fe i Zn u ishrani. Sa druge strane, L1 i L4 su takođe linije kukuruza sa visokim sadržajem neorganskog P, β-karotena i Mn, kao i povoljnim odnosom između fitinske kiseline i Fe i Zn, što im može dati prednost, kao izvoru Mn u selekcionim programima. Iste linije kukuruza takođe bi mogle imati visoku apsorpciju Fe i Zn, zahvaljujući visokom sadržaju β-karotena. Linija kukuruza L14, sa relatvno visokom koncnetracijom sva tri faktora (Fe, Zn i β-karotena) je pogodna za selekcione programe kao osnova za poboljšanje useva kukuruza preko povećanja pristupačnih minerala.