2. Name: sajjad ali M.sc final morning
Session
University of peshawar

3. ARBASCULES

4. Arbuscules
Arbuscules are infolding branched haustoria that formed within a root cortex cell. They were named by Gallaud (1905),
Arbuscules are originated from Intraradical Hyphae (IH) and are formed within the root cortex cell. They can occur sporadically along the roots, but in some cases arbuscules may occur growing nearly from an entry point (Schüßler and Walker )
‘In botany and mycology, a haustorium is a rootlike structure or a structure that grows into or around another structure to absorb water or nutrients,

5. Arbuscule of Gigaspora margarita with an elongated trunk hypha (T) and tufts of fine branch hyphae (arrows)

6. Developing arbuscule of Glomus mosseae in a root cell with fine branch hyphae (arrows). The trunk (T) of this arbuscule branched from an intercellular hyphae

7. Arbuscules can assume one of two types of colonization patterns: (Two distinct morphological types)
1) Arum type (Linear AMF)
2) Paris type (Coiling AMF)

8. 1)Arum type (Linear AMF)
In the Arum-type , the fungi form longitudinal intercellular hyphae in the air spaces between the cortical cells.
The intercellular hyphae then form short side branches which penetrate cortical cells to form arbascule.
In some Arum type AM , hyphal coils are formed within the passage cells of the hypodermis.
However these coils do not usually make up a large component of the intracellular fungal biomass (Smith & Read, 1997).

9. 2) Paris type (Coiling AMF)
In the paris type the intercellular phase of colonization is absent , or virtually
so instead the paris type is characterized by the formation of extensive intracellular hyphal coils and arbasculate coils in the root cortex , spreading directly from cell to cell (Gallud 1905).
The arbasculate coils are similar to hyphal coils , except that they have small highly branched arbascule like structures (Gallud ,1905 : Yawney and Schultz ,1990 ).
As with the Arum type entry coils can also be formed in the hypodermis of roots of Paris type AM (Gallud,1905).

10. a) Arum-type AM b) Paris-type AM

11. Arbuscules formation process

12. Arbascule formation process
Their formation occurs 2 days after root colonization, i.e. , during the symbiotic phase and hyphal growth (Brundrett et al ) ,
but in host-plant bioassays, they require a longer period of time compared to other structures (Walker ).
Another distinctive characteristic of the arbuscule is their limited life time, they begin to collapse after a few days, but hyphae and vesicles can remain in roots for months or even years (Brundrett et al.1985 )

13. Under greenhouse conditions, host plants colonized by species of Gigasporaceae begin to show arbuscules after the third month of inoculation (Walker ).
In species of the Order Glomerales their formation occurs between the second and third month after inoculation (Oehl et al ) .

14. Arbuscules morphology also differs among AMF species
Arbuscules morphology also differs among AMF species. We can observe arbuscules like an intracellular winding (e.g., Scutellospora ) ,
“clouds” format (e.g., Glomus) , or staining weakly in the presence of acid reagents (e.g., Acaulospora and Paraglomus ) (Schüßler and Walker )

15. Life Quote
You can't go back and change the beginning, but you can start where you are and change the ending.”