type mismatch on texture 2D inside scriptable object

Hi I have a scriptable object with a texture2D inside it that is marked as serialized field, now, on creation of this scriptable object, i call a method in it to initialize it and inside that method, i assign the icon (the texture 2D) by reading a static readonly texture 2D on my resources class. when i look at the scriptable object in inspector, the icon shows type mismatch and when i close unity and re run it, the icon is not being serialized. here is code snippets for this :

first the scriptable object itself :

 [Serializable] public partial class NodeSchema : ScriptableObject, ISerializationCallbackReceiver
 {
         [SerializeField] protected Texture2D Icon;
 }

then the initialize method :

 public class TestNodeSchema : Common.Editor.Graph.NodeSchema
     {
         public override void Initialize()
         {
             base.Initialize();
             Icon = Resource.TestNode;
         }
     }

and finally the resources class. keep in mind there is an extension method that accepts a string and loads a texture 2D from the resources i added to the dll library. when i add the scriptable object, the resource loads correctly first but i get the type mismatch, then on re running unity, the field becomes empty indicating that the texture is not being serialized properly.

 public static class Resource
     {
         public static Texture2D TestNode = "Test".LoadTexture();
     }

What am i missing here?