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
Genetically modified organism if it still has the same effect on phenotype. Other strategies include attaching the gene to a strong promoter and see what happens when it is over expressed, forcing a gene to be expressed in a different location or at different developmental stages. Some genetically modified plants are purely ornamental. They are modified for lower color, fragrance, flower shape and plant architecture. The first genetically modified ornamentals commercialised altered colour. Carnations were released in 1997, with the most popular genetically modified organism, a blue rose (actually lavender or mauve) created in 2004. The roses are sold in Japan, the United