What four kinds of plants did Tiangong-1 carry? Tell me the reasons for recommending these plants.

Tiangong-1 is equipped with four plants: Putuo Carpinus, Davidia involucrata, Wangtianshu and Rhododendron grandiflora.

These plants are recommended because their genes are defective and cannot adapt to the environment better. They want to use cosmic rays in space to act on plant chromosomes, induce gene mutation, improve the genes of rare plants, increase the genetic diversity of plants, make up for the defects in plant genes, make rare plants better adapt to adverse environment, survive and protect these rare plants.