MORPHOLOGY, FUNCTION OF SORI AND VARIATIONS OF THE LIFE CYCLE OF RUSTS

ABSTRACT

The organisms that are generically called rusts form an ample and complicated group. More than 100 genera that include about 6000 species are known today. In Brazil only about 1000 species belonging to 55 genera are known. The rusts belong to the group of fungus organisms, and are very old. Under the biological point of view, there is no doubt that the rusts have been successful, having been able to parasite for such a long period, and with such a varied geographic distribution. This must be due to the fact that they are capable of producing diverse spore forms that are involved in many complex types of life cycles. Thus, these variations provide the rusts with surprising abilities of adaptation in different environmental conditions.

KEY WORDS
Uredinales; Puccinia ; Hemileia ; Phakopsora