By default, no, there's no shortcut.

You can create one yourself though:

1. Open System Preferences → Keyboard → Shortcuts → App Shortcuts.

2. Click the + button to add a new shortcut.

3. Set the Application to Numbers.app, and the Menu Title to Delete Row.

   

4. Set your keyboard shortcut and press Add.

With Numbers 11 and earlier, by default, no, there's no shortcut.

You can create one yourself though:

1. Open System Preferences → Keyboard → Shortcuts → App Shortcuts.

2. Click the + button to add a new shortcut.

3. Set the Application to Numbers.app, and the Menu Title to Delete Row.

   

4. Set your keyboard shortcut and press Add.