Lately, I transported some plants from friend...now strawberry and blackberry leaves are turning brown and I wanna know the reason.
Leaves of Strawberry and Blackberry Turning Brown
Certified GKH Gardening Expert
This looks to be either Strawberry Leaf Spot or Strawberry Leaf Blight.
Cultural practices are the recommendations to control these diseases.
In the image your soil looks quite wet, along with the leaves on your plants.
Well draining soil and keeping watering from splashing onto the leaves.
Crop rotation will also help in controlling these fungus diseases.
Here are some articles with more information.