Alternaria

Alternaria diagram

General characteristics

1. Alternaria is a genus of saprophytic fungi, which causes spot diseases in plants (as facultative saprophyte) and also survives as endophytes.
2. Mycelium is well-branched, spetate and multinucleate.
3. From the hyphae, erect, branched and tubular conidiophores grow into the air.
4. Short conidiophores arise from the hyphae growing in or on substrate and grow aerially.
5. Malanized (dark colored) conidia are borne singly or in chain exogenously at the tip of conidiophore.
6. The young conidium first divides by transverse septa and some of its cells divide by longitudinal septa.
7. Conidia with transverse and longitudinal septa are called ‘muriform' (for 'brick-like' appearance) or dictyospores.
8. Conidia are obclavate or elliptical being broadest near the base and gradually taper to an elongated beak.
9. In the presence of moisture and suitable temperature conidium germinates by producing 5-10 germ tubes.

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Content first created on 14-12-2022
last updated on 14-12-2022