In this article we will discuss about the similarities and dissimilarities between rusts and smuts.
Similarities between Rusts and Smuts:
(i) The mycelium in both passes through two stages, the monokaryotic (primary) stage and the dikaryotic (secondary) stage.
(ii) The dikaryotic mycelium is of greater importance. It is usually perennial in both. It is intercellular and obtains nourishment by means of haustoria. It produces teleutospores.
(iii) Motile cells in the life cycle of both smuts and rusts are lacking.
(iv) The teleutospores in both are resting spores and on germination produce basidiospores. Ustilago tritici is the only exception.
(v) The tertiary mycelium and basidiocarps are lacking in both.
(vi) The dolipore parenthesome septal complex, which is a hallmark of the Basidiomycetes, is absent in both the rusts and smuts.
(vii) In nature both appear to be obligate in their parasitism but recently the scientists have been able to grow both on culture media as facultative saprophytes.
Dissimilarities between Rusts and Smuts:
1. Wheal rusts are heteroecious and others are autoecious.
2. The rusts are intercellular and obtain their nutrition by means of haustoria. Clamp connections on the secondary mycelium are rare.
3. The dikaryotic mycelium produces three kinds of binucleated spores; uredospores and teleutospores on the primary host and aeciospores on the alternate host.
4. The teleutospores arc developed from the terminal cells of the mycelium.
5. The teleutospores are stalked. 2-celled and each cell is binucleate.
6. Each cell of the 2-celled teleutospores produces an epibasidium which bears four basidiospores. They are borne on sterigmata and arc discharged violently by the water drop method.
1. All smuts are autoecious.
2. The smuts may be intercellular or intracellular (U. maydis). Haustoria are present. Clamp connections are common.
3. It produces only one kind of binucleate spores called the smut pores which are comparable to the teleutospores of rusts.
4. Smut spores are formed from the intercalary cells.
5. The brand spores (teleutospores) are unicellular and binucleate.
6. The single-celled, brand spore which is equivalent to teleutospores, germinates to produce a single epibasidium which bears a variable number of basidiospores. They are not borne on the sterigmata nor are they discharged violently.