How can we store different type of complex list into a generic list type varible?

See more:

.NET

C#4.0

Point 1: I have the below class structure

//First Class, which is having MainModel
public class MainModel
{
    public List<employee> Employees { get; set; }
    public List<department> Departments { get; set; }
}
[Serializable]
public class Employee
{
    public Int64 EmpId { get; set; }
    public string EmpName { get; set; }
    public DateTime? DOB { get; set; }
    public decimal? Salary { get; set; }
}
[Serializable]
public class Department
{
    public Int64 DeptID { get; set; }
    public string DeptName { get; set; }
    public List<employee> Employees { get; set; }
}

Point2: All the class are loaded with some data.

Point3 I have an object of MainModel as mainModel

Point 4 I have written the below code to get the data dynamically from the list properties of MainModel class and store it in generic list variable, and finally I have to use that list at some other place.

Type objType = mainModel.GetType();
PropertyInfo[] properties = objType.GetProperties();

PropertyDescriptorCollection propAttributes = TypeDescriptor.GetProperties(typeof(MainModel));
int i = 0;

foreach (PropertyInfo property in properties)
{
    //Description about properties
    PropertyDescriptor prop = propAttributes[i];
    string propName = prop.Name;
    Type type = prop.PropertyType;
    
    //Data of properties
     object propValue = property.GetValue(mainModel);
     IEnumerable Data = propValue as IEnumerable;
}

Point 5 If you look at the above code, I have a variable named propValue of object type, In that variable, on the basis of iteration values propValue variable gets populated with data of List < Employees> and List< Department>

Note: I have to get value of propValue variable and store it in some kind of generic list, so that I can pass it to some method which accept any type of list.

Please suggest