Minimum Distance Spanning Tree Dijkstra
Like other have pointed out, it seems you are confused by the difference between a minimum spanning tree, and a shortest path tree.

A minimum spanning tree, is a tree such that it spans all vertices, and the sum of all edges is as minimum as possible.

A shortest path tree, is a rooted tree such that the distance between the root, and any other vertex is as minimum as possible. (That doesn't necessary mean that the sum of its edges has to be minimum as possible).