how to bind array to nested field with Jquery in ASp.NET mvc

I have a ViewModel Like this :

public class SaveWorkOrderViewModel
{
    public Guid WorkOrderId { get; set; }
    public List<SaveWorkOrderDelayReasonViewModel> DelayReasons { get; set; }
}
public class SaveWorkOrderDelayReasonViewModel
{
    public Guid DelayReasonId { get; set; }
    public string Title { get; set; }
}

and I have controller that get SaveWorkOrderViewModel as param Like this :

[HttpPost]
public virtual JsonResult Save(SaveWorkOrderViewModel saveWorkOrderViewModel)
{
    ....
}

to bind data to this I tried like this :

var workOrderId = $(this).data('workOrderId'); // return guid
var DelayReasons = $("#drpdelay").select2("val"); // return array of guid
var saveWorkOrderViewModel = {
    workOrderId: workorderId,
    DelayReasons: {
        DelayReasonId:DelayReasons 
    }
};

but when Post Page , I getting null for DelayReasons.

I couldn't find any similar post to solve this .

updated :

My script for send ajax call is :

$.ajax({
    url: '@Url.Action(MVC.Admin.WorkOrder.Save())',
    data: { saveWorkOrderViewModel },
    type: "POST",
    success: function (data) {
        showMessage(data.message, data.notificationType);
        if (data.result) {
            RefreshKendoGrid('woGrid');
        }
    },
    error: function (response) { }
});

Finally I changed scrips like this and its work fine :

var fields = [];
$(delays).each(function (index, value) {
    var obj = {};
    obj["DelayReasonId"] = value;
    obj["Title"] = null;
    fields.push(obj);
});

var saveWorkOrderViewModel = {
    workOrderId: workorderId,
    DelayReasons: fields
};