Can't set default value to ion-select from component ionic 3

Question

I am trying to set default value to ion-select from component class but when page gets load ion-select component doesn't show default value.

My component code is as below:

@Component({
  selector: 'page-edit-profile',
  templateUrl: 'edit-profile.html',
})

export class EditProfilePage {
  user=new User("","","Male","","");
  gender:string="Male";
  constructor(public navCtrl: NavController, public navParams: NavParams) {
     console.log('inside EditProfilePage constructor ');
  }
}

HTML page code is as below:

<ion-item>
  <ion-label>Gender</ion-label>
  <ion-select [(ngModel)]="gender" name="gender">
    <ion-option value="Male">Male</ion-option>
    <ion-option value="Female">Female</ion-option>
  </ion-select>
</ion-item>