Puccinia
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Puccinia is a genus of fungi that causes rust diseases. It is an obligate parasite with a complex life cycle involving two different hosts. Puccinia graminis causes black rust of wheat. It has both a primary host of wheat and an alternate host of barberry. Its life cycle includes uredinial, telial, basidial, pycnidial/spermagonial, and aecidial stages that allow infection of both hosts through the production of spores.
Puccinia
- 1. PUCCINIA Kingdom : Fungi Division : Eumycota Sub-Division : Basidiomycotina Order : Uredinales Family : Pucciniaceae Dr Renjana PK Assistant Professor Dept of Botany Govt College, Kodanchery
- 5.  Rusts  Obligate parasite  Autoecoius or heteroecius  P. graminis – Black rust/stem of wheat Two hosts- heteroecious – Primary host & alternate host Wheat (Dikaryophase) Barberry (Haplophase)
- 6. Uredineal stage Telial stage Basidial stage Pycnidial/ spermagonial Aecidial stage WHEAT BARBERRY
- 7. UREDINEAL STAGE  Formed by the germination of aeceidiospore on wheat  A uredosorus is formed  Binucleate, oval to round  Reddish brown pustles- Red stage  Means of secondary infection
- 9. TELIALSTAGE  Formed by the gradual replacemnt of uredosori  Black stage, teleutospore  2-celled, binucleate, clavate  Thick & smooth walls  Undergo a period of rest  The 2 nuclei fuse to form a diploid nucleus
- 13. BASIDIAL STAGE  Germination of teleutospore  Promycelium becomes the basidium  4 basidiospores by meiosis  Germinates on Barberry  Forms the haplomycelium  Produces pycnidium on stage on upper side & aecidium on lower side
- 14. PYCNIDIAL/SPERMA GONIAL STAGE  Flask shaped pycnidium/spermagoniu m on the upperside  Ostiole & periphyses  Palisade like spermatial hyphae  Non moile single celled spermatia  Long receptive hyphae  Transfer of spermatium of one strain to receptive hyphae of another strain  A binucleate cell is formed
- 17. AECIDIAL STAGE  Dikaryotic mycelium organises cup shaped structures  Lower side, peridium (wall)  Aecidiospores in basipetal succession  Intercalary cells  Binucleate, thick walled  Sub globose to polyhedral  Liberated aecidiospores germinate on wheat plants