Chrysanthemum white rust Chrysanthemum white rust Chrysanthemum white rust is a disease of plants caused by the fungus Puccinia horiana that infects species of the genus "Chrysanthemum". Chrysanthemum white rust was first identified in Japan, although it is now established throughout Asia, Europe, South America. It has been found in the United States, Australia, and New Zealand on several occasions, but early detection and eradication efforts have prevented the disease from becoming established in these countries. Plants infected by chrysanthemum white rust exhibit spots on the upper surfaces of leaves. These spots are initially pale-green to yellow in color and up to 5mm
Multicellular organism somatic embryogenesis (e.g. land plants, most algae, many invertebrates). One hypothesis for the origin of multicellularity is that a group of function-specific cells aggregated into a slug-like mass called a grex, which moved as a multicellular unit. This is essentially what slime molds do. Another hypothesis is that a primitive cell underwent nucleus division, thereby becoming a coenocyte. A membrane would then form around each nucleus (and the cellular space and organelles occupied in the space), thereby resulting in a group of connected cells in one organism (this mechanism is observable in Drosophila). A third hypothesis is that as a