Rust (fungus) of the rust fungi "Cronartium ribicola", preventing the formation of basidiospores which infect the primary host. Although spores from white pines cannot infect other white pines, survival spores may overwinter on infected pines and reinfect "Ribes" spp. the following season. Infected tissue is removed from white pines and strict quarantines of "Ribes" spp. are maintained in high risk areas. "Puccinia graminis" is a macrocyclic heteroecious fungus that causes wheat stem rust disease. The repeating stage in this fungus occurs on wheat and not the alternate host, barberry. The repeating stage allows the disease to persist in wheat even though the
Human uses of plants or dried flowers. Ornamental plants have sometimes changed the course of history, as in tulipomania. Basic biological research has often been done with plants. In genetics, the breeding of pea plants allowed Gregor Mendel to derive the basic laws governing inheritance, and examination of chromosomes in maize allowed Barbara McClintock to demonstrate their connection to inherited traits. The plant "Arabidopsis thaliana" is used in laboratories as a model organism to understand how genes control the growth and development of plant structures. NASA predicts that space stations or space colonies will one day rely on plants for life support. Scientific advances