biology

1. 1
Division Mycota
Subdivision Eumycotina
Class Ascomycetes
Sub-class Euascomycetidae
Series Hymenoascomycetes
Sub-series Discomycetes
Order Pezizales
Family Morchellaceae
Genus Morchella
Species esculenta
Superkingdom Eukaryonta
Kingdom Mycetae
Division Amastigomycota
Subdivision Ascomicotina
Class Ascomycetes
Sub-class Hymenoascomycetida
Series Discomycetes
Order Pezizales
Family Morchellacea
Genus Morchella
Species esculenta

2. 2
The genusincludesa numbersof species. The importantones are Morchellaconica,M. elata,M. esculenta,M. hybrid,
and M. crassipes.All the species grow as saprophytes. There isa suggestionthat some speciesof Morchellaare
mycorrhizasbut there is no proofto substantiatethis. In Indiait isknown as Guchhi.
- It mostly growsin soil rich organicmatter usuallyinthe dense deciduousforestlitter and fruitsin spring.
- It is one of the delicious,ediblefungi whichare tasteful articlesin humandiet. The edible partis
the fructification.The fructificationsarecooked with rice and vegetables andeaten all over India.
- It is inconspicuousbutextensiveandsubterranean. It grows a few inchesdeep inthe soil andthus hidden
from view. The myceliumconsistsof a massof looselyinterwovenbranched hyphae.The hyphaeramifythroughthe
interstices ofthe soil nourishing themon the organicmaterial.Each segments or cell containsseveral nuclei.Under
adverse circumstancesthe mycelia producesclerotia.
- It beginsas a dense knot ofhyphae. Underfavourableconditionsoffoodand moisturethe
myceliumhyphaegrow rapidlyand branchrepeatedly. They get interwovento formdense compact masses. These
massesof hyphae are calledthe hyphal knots.They are formedjust beneath the surface of the soil.Each hyphal knotin
the presence ofabundantfoodand moisturedevelopsinto an aerial stalked fructification calledanAscocarp.
- The fructificationor the Ascocarpis a spore producingstructure. The mature ascocarp consistsofa stalk like
portionthe stipe surmountedby a hollowconical cap likeobject the pileus. It is thick,Fleshy andhollowwitha waxy
surface. The colourvaries from a dirty greyishwhite to a dark brown dependingonthe species andthe age. The terminal
conical cap or the pileusconstitutesthe fertile portionofthe ascocarp. The ridgesunite the fertile areas whichform an
irregularlydistributedhymeniumor thecium. A thinsection (figureMorchellaSp. Section throughdepressionof the
pileusshowingparaphysesandasci) throughthe depressionreveals that it islined by a fertilelayer called the hymenium
or thecium. Intermingledwiththe asci are elongated sterile slenderhyphae calledthe paraphyses? Beneath the
hymeniumis the sub-hymeniumorhypothecium.
A cross-sectionthroughthe stipe reveals that it is made upof pseudoparenchymatoustissue.Thistissuein the regionof
the depressionof the pileusforms the hypothecium.
- The tipsof mature asci abovethe level of the hymeniumand turn towardslightbeing positively
phototrophic.The residual cytoplasmwithineach ascuschangesinto sugarsof highosmoticvalue. The latter absorb
water. As a result considerableamountof pressure is set up in the asci.The pressure set up withinthe asci aidedby the
turgor pressure set up in the paraphysescauses the release of ascosporesthrougha preformed apical pore whichopens
by a lidhingedat the top ofthe ascus.The internal force projects the ascosporeshighup into the air where they are
caughtup by the aircurrents. The explosionsofthe asci are successiveand not simultaneous.The pileusgraduallyshrinks
as it dries up.Eventuallyit withers. The ascosporesare large colourlessoval andmultinucleate when mature.
- It is reported that the catabolicactivitiesin the ripe fruitingbodyare highduringthe periodof
dehiscence. Thisis indicatedby the marked rise in the temperature ofthe tissue.Conventional currentsare set upin the
surroundingair.These are inducedby the warm tissue of the ripe fructification.Theseconventional currents ofair are
suggestedto playan importantrole inthe dispersal ofthe liberate ascospores.They are carried by windto distant
places.

3. 3
- Onfallingona suitablesoil each ascosporegerminates to produce a new myceliumsoonafter
release. The ascosporesthat happento fall on unsuitablesoil perish.Ascosporesdo notremain viableafter one year near
the soil surface. Accordingto the latter the ascosporesgerminate anddevelop extensivemyceliumat 15◦c under highly
nutritiousnon-competitiveconditions.
- The sex organs whichconstitutethe accessoryparts of sexual process are completely suppressedin
Morchella.Consequentlythe sexual process isextremely simplified.Itinvolvestwodistinctprocesses:
- Itconsistsinthe unionofcytoplasmic contentsof two cells withoutnuclear fusionwhichisdelayed.
This resultsin a sequence of binucleatecell generationsconstitutingthedikaryophase.
- The two nuclei in the ascus mother cell fuse.The fusioncell with a diploidnucleusiscalledthe young
ascus.It represents the transitory diplophasesinthelife cycle.
the youngascuscell elongates.The synkaryon in the ascusundergoes two successivedivisions.These
constitutemeiosis.
(Graphicrepresentationof the lifecycleof morchella)
SalientFeature- 1Morchellaisa saprobicdiscomycete.
2 The so calledmorels(guchhi)are the aerial fructificationsorascocarpsof the fungus.
3 The pileushasa pittedsurface.
4 Asexual reproductionsbysporesare lacking.
5 Nohookformationtakesplace.