How to open or close mat-select programmatically?

Question

I want to open or close mat-select programmatically, i.e.

Here, is my code, now, I want to control open or closed list from the component.

<mat-select placeholder="*Cities"
                  name="fromCity"
                  [(ngModel)]="studentModel.City"
                  (click)="openDialog()"
                  required>