Select the option that can be used as a one-word substitute for the given group of words.

Dwarfed varieties of trees and shrubs in pots

The correct option is Bonsai.

Let's break down the meaning of the given phrase and analyze each of the options to understand why "Bonsai" is the correct one-word substitute:
1. Bonsai: This is the Japanese art of growing ornamentally dwarfed varieties of trees and shrubs in pots or small containers through careful pruning and training. This matches the definition in the question perfectly.
2. Bonafide: This term means genuine, real, or made in good faith (for example, "a bonafide signature"). It has no relation to trees or plants.
3. Orchard: This refers to an intentional planting of domesticated fruit or nut trees for commercial or personal food production, typically grown in the ground rather than as dwarfed trees in pots.
4. Botanical: This is an adjective that relates to plants or the study of plant biology (botany), which is a general term rather than a specific name for potted dwarf trees.

Therefore, Bonsai is the correct one-word substitute.