JavaFX2 ChoiceBox populate with values

Question

I'v this kinda of question, but none of the suggested solutions helped.

I am using JavaFX 2.2, Java 6.

I have ChoiceBox defined in FXML:

<ChoiceBox fx:id="companyList" prefHeight="25.0" prefWidth="300.0" />

then I have reference to it in my "Main" class:

@FXML
public ChoiceBox<String> companyList;

Inside "start" method I try to populate it with values like this

companyList = new ChoiceBox<String>();
companyList.setItems(FXCollections.observableArrayList("One","Two","Three"));

But no values are added to list; I'v tried in many different ways suggested in: Populate Choicebox defined in FXML How do I populate a JavaFX ChoiceBox with data from the Database? JavaFx 2 ChoiceBox with custom item

I don't get any compilation errors, but it just don't work, what I am doing wrong?

(PS I am new to Java)

EDIT (SOURCE)

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<GridPane focusTraversable="true" prefHeight="435.0" prefWidth="320.0" snapToPixel="false" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Main">
   <Pane prefHeight="425.0" prefWidth="300.0" GridPane.columnIndex="1" GridPane.rowIndex="1">
      <VBox>
         <VBox minHeight="50.0">
            <Label prefHeight="25.0" text="Įmonė kuriai generuojamas išrašas" />
            <ChoiceBox fx:id="companyList" prefHeight="25.0" prefWidth="300.0" />
             <!-- other markup is irrelevant-->

Main class:

package sample;

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.stage.Stage;

public class Main extends Application {
    @FXML public ChoiceBox<String> companyList;

    @Override
    public void start(final Stage primaryStage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("IST Billing Generator");
        Scene scence = new Scene(root);
        primaryStage.setScene(scence);

        companyList = new ChoiceBox<String>();
        companyList.setItems(FXCollections.observableArrayList("One","Two","Three"));

        this.primaryStage = primaryStage;
        primaryStage.show();
    }
    //other code is irrelevant too
}