Morchella
Q.1. What is sponge mushroom ? Give its economic importance.
Ans. Sponge mushroom is a type of fungi. It is saprophytic. It mostly grows in soil rich in organic matter usually in the dense deciduous forest litter and fruits in the spring. Spong mushroom is also known as morchella Morel and Guchhi.
Economic Importance:-
It is one of the delicious, edible fungi, which are tasteful articles in human diet. The edible part is the fruitification. The fruitifications are cooked with rice and vegetables and eaten all over India particularly in the Punjab. It is more common dish with the vegetarians and considered as good as meat of fish.
Q.2. Write about development and fruiting body of Morchella.
Related Questions -
Q. Write short note on Ascocarp of Morchella. (2012)
Q. Give the life history of Morchella.
Q. Where will you find Morchella ? With the help of suitable diagrams describe the process of sexual reproduction in it. ( 2007)
Q. Describe the systematic position and important character of morchella. ( 2005, 10, 13)
Q. Describe the systematic position and important characters of morchella. (2005, 10)
Q Give the systematic position of Morchella. ( 2007)
Ans. Systematic Position: -
Division - Mycota
Sub-division - Eumycotina
Class - Ascomycetes
Order - Pezizales
Family - Helvellaceae
Genus - Morchella
It is a common saprophytic fungus growing on decaying wood, organic matter etc. The commonest and best known species is M. esculenta. It is a also known as sponge mushroom or guchhi It is used as a vegetable.
Structure:-
The mycelium is inconspicous and formed in the soil bumus. It consist of many celled, much branched hypha which penetrate the soil.
Structure and Development of Fruiting Body ( Ascocarp ) :-
On favourable condition hyphal mass develops into a fruiting body. The development of ascocarp is very rapid the size varies from 1” to 5” in length and has thick fleshy hollow stalk or stipe. It is cream coloured. At the apex of stipe occurs a fertile heart shaped pileus which is rigid looks like a sponge. It is white to brown in colour.
Internal Structure of Ascocarp:-
The stripe consists of interwoven hyphae and looks as pseudoparenchymatous structure. In the depressions of ascocarp the hymenial layers are present which consist of innumerable elongated, cylindrical asci containing ascospores and paraphysis on meturation of the asci. They become elongated and break at the tip and release of ascospores.
Ascospores are dispersed by wind in favourable conditions. They germinate by producing germ tubes which develop into new mycelia.
Sexual Reproduction:-
The sex organs are completely suppressed in Morchella. Sexual process involves two distinct processes, namely, plasmogamy and Karyogamy. The latter followed by meiosis.
1. Plasmogamy:-
In this process the union of cytoplasmic contents of the two cells without nuclear fusion occur. Thus, by plasmogamy the dikaryophase is formed. In this process fungus dikaryophase can be established by two methods.
( i ) Somatogamous Copulation :-
In this process two vegetative hyphae of the subhymenium region of the pileus come in contact. At the point of contact the intervening walls between the copulating cells dissolve. The two multinucleate protoplaste intermingle in the fusion cell. Two functional nuclei, one from each copulating cell, form dikaryon. All other nuclei in the fusion cell disappear. After sometimes ascogenous hyphae arise from the fusion cell. Each young ascogenous hypha receives a pair of nuclei. The terminal cells of these hyphae function as ascus mother cells.
(ii) Authogamous Pairing:-
In this case any vegetative cell of the sub - hymenium may establish a dikaryon. The remaining nuclei in the cell degenerate. The cells with dikaryons develop ascogenous hyphae as in somatogamous copulation.
(2) Karyogamy:-
The two nuclei in the ascus mother cell fuse. The fusion cell with a diploid nucleus is called the young ascus. It represents the transitory diplophase.
3. Meiosis:-
The young ascus cell elongates. The synkaryon in the ascus undergoes two sucessive divisions. These constitue meiosis. The four haploid nuclei are formed. Further these nuclei undergo mitotic mitotic divison. In this way 8 daughter nuclei are formed in each ascus cell. Each of these is fashioned into an ascospore.
Fig. Sexual reproduction in Morchella.
Q.3. Draw neat and labelled diagram of V. S. of Ascocarp of Morchella.
(2005, 13)
Related Question -
Q. Make a labelled diagram of Ascocarp of Morchella. (2010)
Fig. - V. S. of Ascocarp of Morechella