Biotrophic fungi usually penetrate the rigid cell wall via the formation of a specialized infection structure on the plant

surface called an appressorium. Then, the emerging penetration

peg breaches the rigid plant cell wall and provides entry into the plant cell. Finally, a haustorium forms upon entry into the plant cell.

TLS Online TPP Program

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#Unit 10. Ecological Principles

Primary succession

TLS Online TPP Program

#Id: 2190

#Unit 10. Ecological Principles

Facilitation model =  Species are facilitated by previous colonists

Inhibition model =  They are inhibited by the action of previous colonists

Tolerance model  =  They are unaffected by  previous colonists/ New pioneer neither inhibit nor facilitate 

TLS Online TPP Program

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#Unit 10. Ecological Principles

Secondary succession

TLS Online TPP Program

#Id: 2192

#Unit 10. Ecological Principles

Sequential changes in community structure over physical distance, primarily influenced by time, constitute a chronosequence

TLS Online TPP Program

#Id: 2193

#Unit 10. Ecological Principles

TLS Online TPP Program

#Id: 2194

#Unit 10. Ecological Principles

Facilitation may be important in early seral stages and inhibition important in later ones or vice versa.