NPC and Palynology along with its importance .

This presentation wants to offer a bird's eye view of the NPC system of classification of pollen grains along with its importance in the field of academic attainments and biological research.

1. WELCOMETO
NPC SYSTEMINPALYNOLOGY
BYDR. N.SANNIGRAHI,
ASSOCIATEPROFESSOR,
DEPARTMENT OFBOTANY, NISTARINI
COLLEGE, PURULIA, 723101(W.B) INDIA.
Reproductive biology

2. WHAT IS NPC?
G.Erdtman(19069)proposedthesystemoftheclassificationof
pollengrainsonthebasisofthenumber,positionandcharactersof
thepollengrainaperture.
ThisiswellknownasNPC–system.
Underthissystem,theterm‘treme’(aperture)hasbeenusedfor
preparingthekeysfortheclassificationofthepollengrains/spores.
Apertureistheopeningorthinningoftheexinewheretheintineis
usuallythick.
Physiologically,thisthinningzoneisagerminationzoneora
harmegathus(Amechanismaccommodatingchangesinvolumeof
thesemirigidpollenexine).
Withregardtotheirposition,theaperturesarepolar,globalor
equatorial.
Thepolaraperturesareeithermonopolar(eitherproximalordistal)
orbipolar

3. POLLENCHARACTERS& NPC
Pollengrain,the1
st
cellofthemalegametophytecanbeCharacterizedbya
numberofmorphologicalcharacterstomakeitsidentificationwithadegree
ofaccuracyfordifferenttaxonomicattributes.
Pollenunits,Polarity,Symmetry,shape,size,Apertureandsporodermare
someofthefeaturestakenintoaccountforthesame.
NPC-systemofpollenclassificationbasedontheapertures,their
Number(N=single/two/many),Position(P=Position;Polar,Distal,Proximal,
globaletc)&Characters(C=characters;circularorelongated)withregardto
themicrosporetetrad.Treme’–isusedforpreparingkeysofpolleninthis
regard.

4. POLLENGRAIN

5. NPC ATAGLANCE

6. WHATNPC STANDSFOR?
InNPC,somedigitsareassignedtodesignateitasfollows:
Thefirstdigitconveystheinformationaboutpresenceorabsenceof
aperturealongwithnumber
Theseconddigitstatesthepositionofaperture(S),i.edistal,proximal,
meridonial,equatorialetc.
Themicrosporesrevealthepositionofaperturewithdesiredclarity.
Thethirddigitstatesthenatureofthecharacterofaperturei.ecircular,oval,
elongatedetc.SoN=Number,P=position&C=Charactersofaperture.e.g.

7. NUMBEROFAPERTURE
N=NumberofaperturepresentinPollengrainsanditisdividedunder7
groups.
ThegroupsareN1-N7
Grainwithoutapertureiscalled‘Atreme’
N1=OneaperturesoastoN7ormore.
N1-N7arereferredasmonotreme,ditreme,tritreme,tetratreme,pentatreme,
hexatremeandPolytreme(Trema=HoleinGreek)
TremewithoutpollengrainsaredenotedasN0.
AnotherspecialgroupN8-anomotremearesuchheterogeneousgroupwhere
thepollengrainshaveoneorseveralirregularapertures.

8. NPC IMAGES

9. P=POSITION
In NPC, P’ indicates the position of aperture in a pollen grain.
Thepositionmaybeproximal,distalandequatorial.
Therearealtogethersevengroupsofaperturebasedonposition-P0-P6.
PollengrainshavingP0grouphaveuncertainpositionofaperture.
P1pollenaperturearecatatreme,inproximalfaceandtheproximalpartis
thefaceofthepollengrainsthatfacesinward/nearesttothecentreoftetrad.
P2-Anacatatremewheretheaperturesarebothproximalanddistalfaces.
P3-Anatremeindistalface
P4-Zonotremewhentheaperturesarelocatedontheequatorialzone.

10. IMAGESOFPOLLENGRAINSWITHRESPECTTOPOSITIONOF
APERTURE

11. CHARACTERS
P5-Diazonotreme are like zonotreme but two rows of apertures
on the equatorial zones.
P6-Pantotreme where pollen grains are globally distributed all
over the pollen surface.
CHARACTERS GROUP
C=denotes the character of an aperture in a pollen grain.
Pollens have C0-C6 but C0 groups characters in still in a state
of flash.
C1-known as Leptoma and 1 one leptoma is called Monolept.
The leptoma may occur either proximal or distal face of pollen
.It is Catalept if present in the proximal face or Analept if in the
distal face

12. CONTINUATION------
C2groupsarecalledTrichotomocolpate(Tricha=3partstome,cut;kolpos,
depression)
Threebranchedapertureandthebranchesaremorethantwotimeslonger
thanbreadth.
Theremainingcharactersclasses–C3,C4,C5andC6includeColpate,
Porate,ColporateandPororateasfarasthenumberofapertures.
Onthebasisoftheabovecharacters,thepollengrainshavebeen
categoricallyclassifiedforidentifyingthepollengrainsinthebranchesof
palynologyforeasyidentificationandthesegregationofthedifferentclose
relatedtaxaasfarasthetaxonomicviewpoint.

13. EXAMPLES
Onthebasisofclassification,eachpollengrainhavespecificidentityas
follows.
Thefirstdigitindicatesnumberofaperture.e.g100formonotreme,200for
ditreme,300fortritreme,400fortetratreme,500forpentatreme,600for
hexatreme,700forpolytreme,800foranomotremeand900foratremeso
no.
Theseconddigitsindicatesthepositionofaperture,e.g.010toproximal
aperture,030fordistalaperture,040forequatorialaperture,060forglobal
aperture.
The3
rd
digitincludescharactersofapertures,e.g.002fortrilete,003for
colpate,004forporate,005forcolporate.
Thereforeifanypollengrainsisdenotedas112thatmeansitisatrillete
grain,133formonosulcate,343fortricolpateand345totricolporategrains
etc.

14. SIGNIFICANCEOFNPC SYSTEM
NPCsystemofclassificationofthepollengrainsextendsalotof
informationasfarascharacteristicfeaturesandthesedataarewidelyused
inplantbiologydomainforitsvarsatility.Someofthesignificancesareas
statedbelow:
i.Itismostsimplesystemofclassificationthathelpstodifferentiateamong
largeheterogeneousgroups.
ii.Monocotsareinaperturate,monosulcateandmonoporatepollengrains
whiledicotsaremeridonialfurrowswithpolyaperturate.
iii.NPCmakesthedescriptionofaperturesprecise.
iv.Itishelpfultoidentifythefamilyorgenusorevenspeciesofapollen
grainwiththeaidofNPCincombinationofothermorphological
attributes.

15. SIGNIFICANCE
Palynologists accepted the NPC classification for its simplicity and
consistent approach to classify the pollen grains.
The alpha taxonomy has been highly enriched with the aids of these
taxonomic attributes.
Thus, the NPC system is a good tool for the plant biologists for the sake of
understanding of the plants diversity in classical approach.
In addition to these, the NPC system offers a huge potential for the research
and academic attainments in the plant reproductive biology.

16. THANKS TO VISIT THE PAGE
REFERENCES:
Google for images,
Different WebPages for the study material.
A Textbook of Palynology-Bhattacharya, Majumder and
Bhattacharya
Disclaimer:ThisPPThasbeendesignedforacademicpurposes.The
authordoesnotclaimanykindoffinancialinterestinthisregard.It
isanendeavortoreachtheunreachedacademicfraternity.