Biofortificación agronómica y genética con zinc de genotipos de trigo harinero (Triticum aestivum L.) en clima mediterráneo

Abstract

The combination of plant breeding and agronomic biofortification is the most reasonable approach to minimize Zinc (Zn) deficiency problems, it was affected almost the third of the world population. Fields experiments were conducted in south-eastern part of Portugal, where soils are deficient in Zn. In first field experiment over 2 years, thirteen cultivars of bread-making wheat were fertilized with four ZnSO4 7 H2O treatments: i) control, ii) soil Zn application, iii) foliar Zn application and iv) both soil and foliar Zn application. A second field experiment was realized with six cultivars in 2012/13 with other two ZnSO4 7 H2O and N treatments: one foliar ZnSO4 7 H2O with N application, and soil and one foliar ZnSO4 7 H2O with N application. Low rainfall produced 46% more of grain Zn content but about 67% less of grain yield. Whereas foliar and combined soil+foliar application up growth caused to 20 mg Zn kg-1; soil application up growth caused to 350 kg ha-1 in yield but not on the content of Zn; combined application Zn caused average increased. Genetic biofortification was not enough to produce grains with enough Zn. The cultivars behaved differently in their capacity to accumulate Zn in the grain, being INIAV-1, INIAV-6, INIAV-9 and the commercial varieties the best. The replacement of ZnSO4 7 H2O by one dose of N was not obtained the suitable levels of Zn, being necessary to combine two ZnSO4 7 H2O foliar applications with the selection of the most efficient genotypes to set a biofortification program.