initialize ion-select with data from a JSON in IONIC

Question

I am trying to fill a ion-select in IONIC from data that i get from my backend at the start of the application. This is the JSON i recive:

[{"codRole":15,"codEvent":43},{"codRole":15,"codEvent":45}]

And this is the ion-select:

[

The code:

import {Component,} from '@angular/core';
import {IonicPage, NavController, NavParams} from 'ionic-angular';
import {ZEUS_URL} from "../../properties/properties";
import {Http} from '@angular/http';
import {Rol} from "../../models/Rol";
import {Evento} from "../../models/Evento";
import {RolEvento, RolEventoJSON} from "../../models/RolEvento";
import {FormBuilder, FormControl, FormGroup} from "@angular/forms";


/**
 * Generated class for the RolePage page.
 *
 * See http://ionicframework.com/docs/components/#navigation for more info
 * on Ionic pages and navigation.
 */

@IonicPage()
@Component({
  selector: 'page-role',
  templateUrl: 'role.html',
})
export class RolePage {

  AMform: FormGroup;
  Name = new FormControl("");
  roles: Rol[];
  eventos: Evento[];
  rolEventos: RolEvento[];
  rolAdmin: boolean = false;

  constructor(public http: Http, public navCtrl: NavController, public navParams: NavParams, fb: FormBuilder) {

    /**Getting events*/
    this.http.get(ZEUS_URL + '/evento/fetch', {withCredentials: true}).map(res => res.json()).subscribe(data => {
      this.eventos = new Array<Evento>();
      data.forEach(element => {
        let temp_event = new Evento(element.codEvento, element.codigo, element.descripcion, element.json_plantilla);
        this.eventos.push(temp_event);
      })
    })

    /**Getting roles*/
    this.http.get(ZEUS_URL + '/rol/fetch', {withCredentials: true}).map(res => res.json()).subscribe(data => {
      this.roles = new Array<Rol>();
      data.forEach(element => {
        let temp_rol = new Rol(element.codRol, element.nombre, element.descripcion, element.eventos);
        this.roles.push(temp_rol);
      })
    })

    /**Getting Events from Roles*/
    this.http.get(ZEUS_URL + '/rolEventoSuscripcion/fetch', {withCredentials: true}).map(res => res.json()).subscribe( data => {
      this.rolEventos = Array<RolEvento>();
      data.forEach(element => {

        let temp_rolEventos = new RolEvento(element.codRol, element.codEvento);
        this.rolEventos.push(temp_rolEventos);
      })
      for (var i = 0; i <= this.roles.length - 1; i++) {
        console.log(this.rolEventos[i])
        this.Name.setValue(this.rolEventos[i]);
      }

    }, err => {
      console.log("Error", err)
    })



    let numRol: number = parseInt(localStorage.getItem('codRol'));

    if (numRol === 15) {
      this.rolAdmin = true;
    }


  }

  //Versión usando modelo RolEvento

  guardar() {

    var resultado: RolEventoJSON[] = [];
    for (var i = 0; i <= this.roles.length - 1; i++) {
      if (typeof this.roles[i].eventos == "undefined") continue;
      for (var j = 0; j <= this.roles[i].getEventos().length - 1; j++) {
        resultado.push({codRol:this.roles[i].getCodRol(), codEvento:this.roles[i].getEventos()[j].getCodEvento()})
      }
    }
    console.log(resultado)
    console.log(JSON.stringify(resultado))



    this.http
      .post(ZEUS_URL + "/suscripcion", JSON.stringify(resultado),{withCredentials: true})
      .subscribe(data => {
        console.log("ok")
      }, error => {
        console.log("error");
      });





  }


  ionViewDidLoad() {
    console.log('ionViewDidLoad RolePage');
  }
}

<ion-header>

  <ion-navbar>
    <button ion-button menuToggle>
      <ion-icon name="menu"></ion-icon>
    </button>
    <ion-title>Conf. de roles</ion-title>
  </ion-navbar>

</ion-header>
<ion-content padding>
  <form>
  <ion-list>
    <ion-item *ngFor="let rol of roles">
      <ion-label>{{rol.nombre}}</ion-label>
      <!-- Cada input necesita un modelo (no uno para todos) -->


      <ion-select  [(ngModel)]="rol.eventos" multiple="true">
        <ion-option [value]="evento" *ngFor="let evento of eventos" >{{evento.descripcion}}</ion-option>

      </ion-select>
    </ion-item>
  </ion-list>

  <button ion-button icon-right block outline color="botones" (click)="guardar()" type="submit">
    Guardar/Submit
    <ion-icon name="checkmark-circle-outline"></ion-icon>
  </button>
  </form>
</ion-content>

The code (doesn't run because its need the data from the backend).

I would like to have checked "ion-option" depending of data from JSON.

Like i am showing a json with only the codes, and not the names, here is the relation:

ROLES TABLE:

'15','ADMIN'

'16','TRAFICO'

'17','RRHH'

'18','ADMINISTRACION'

USERS TABLE:

'43','ALTA TIPO VEHICULO'

'45','BAJA TIPO VEHÍCULO'

Thanks for all!!!