全 文 ：第29卷第5期 中 国 科 学 技 术 大 学 学 报 Vol.29 ,No.5
19 9 9年10月 JOURNAL OF CHINA UNIVERSITY OF SCIENCE AND TECHNOLOGY Oct.1 9 9 9
Parallel Evolution of Aperture Numbers and
Arrangement of Polygonaceae in China
ZHOU Zhongze LU Runlong ZHENG Yanyan
(School of Life Science , USTC)
Abstract Pollen material from dried specimens was obtained from the followng herbaria:
ANU , ANUB , N , NAS.Pollen of 111 species representing 12 genera was examined in the
light microscope(LM)and with the scanning electron microscope (SEM).Pollen descriptions
are given for 28 types based on pollen shape , aperture numbers and arrangement , and the orna-
mentation of exine.The 28 pollen types of Polygonaceae in China have been arranged in their
evolutionary sequence.Evolutionary trends of pollen types of Polygonaceae in China have six
parallel directions.
Key words parallel evolution , aperture , Polygonaceae , China
1 Introduction
The family Polygonaceae consists of some 50 genera with ca.1150 species.The family Polygo-
naceae in China consists of some 13 genera with ca.235 species 37 varieties.According to Nowicke
and Skvarla[ 1] the Polygonaceae is one of the most eurypalynous families among the dicotyledons.An
extensive study of the pollen morphology in the Polygonaceae was published by Wodehouse , Hed-
berg[ 2] , Leeuwen et al , Wang and Feng[ 3] .The present study is a continuation of the studies on
pollen morphology and phylogeny of the Polygonaceae in China(Hong and Hedberg[ 4] , Bao and Li).
The aim of this study is to probe into the phylogeny of 28 pollen types in the Polygonaceae of China.
2 Methods
Pollen of 111 species representing the genera i.e.Aconogonon , Polygonum , Antenoron ,
Pteroxygonum , Fagopyrum , Atraphaxis , Calligonum , Koenigia , Rheum , Rumex , Oxyria ,
Homalocladium was examined in the light microscope and the scanning electron microscope.Pollen for
light microscope was prepared by the standard acetolysis method.Material was subsequently mounted
in glycerine jelly.Pollen was ion-coated with gold-palladium and examined and photographed with a
收稿日期:1999-04-01
周忠泽:男 , 1967年 4月生 ,博士后.邮编:230026 ,合肥
JSM-6300 scanning electron microscope.The LM studies were made using a Leitz Diaplan microscope.
3 Results
Aconogonon-type Pollen grains 3-zonocolpate , (P/E=1.06 ～ 1.40).22.4μm ～ 44.0μm×
17.0 μm～ 34.0μm.Equatorial view elliptical;polar view mostly circular.Ectoaperture———colpus ,
their length c.1/2 ～ 2/3 of the polar axis.Endoaperture———congruent with ectoaperture or absent.
Exine 2.0 μm～ 3.4μm thick , generally one-third of which consisting of the nexine.Sometimes the
exine is a little thicker at the poles than at the equator.Ornamentation:microspinulose-foveolate.
Columellae regularly distributed , more or less densely spaced.Pollen grains of the Aconogonon-type
(fig.1a)occur in 9 species of genus Aconogonon.
(a)Polygonum tortuosum ;(b)P.polystachyum ;
(c)P.senticosum;(d)P.plebeium
Fig.1 Pollen grains of Polygonaceae species
Comments The Aconogonon-type is charac-
terized by being 3-zonocolpate and having an im-
perforate tectum with microspinules.The ornamen-
tation closely resembles that of the Campanulatum-
type and Pangianum-type.The Campanulatum-type
is , however , 6-pantocolpate and the Pangianum-
type 12-pantoporate.The aperture resembles that of
the Cephalophilon-type.The Cephalophilon-type
has , however , a semitectate tectum with a coarse
reticulate ornamentation.
Pollen grains of the Campanulatum-type occur
in the following species Aconogonon
campanulatum (Hook.f.)Hara.and the Pan-
gianum-type occurs in the species Aconogonon pangianum Pal and Maiti.
Cephalophilon-type Pollen grains 3-colpate , mostly subspheroidal , c.25.5 μm ～ 67.5μm.
Equatorial view and polar view circular.Ectoaperture———colpus , long , not sunken;margins distinct ,
irregular.Endoaperture———colpus , congruent with ectoaperture or absent.Exine 3.0 μm ～ 6.5 μm
thick , sexine/nexine 2 ～ 4.Ornamentation:coarsely reticulate.Sexine semitectate , columellate ,
reticulate with well developed lumina and muri;lumina containing smaller , free columellae or no
columellae.Pollen grains of the Cephalophilon-type occur in 9 species of Sect.Cephalophilon excl.
P .criopolitanum , P.palmatum .
Comments The Cephalophilon-type is characterized by being 3-zonocolpate and having a coarse
reticulate ornamentation with duplicolumellate muti.The ornamentation is similar to that of the
Polystachyum-type(fig.1b), Amphibium-type.and persicaria-type(fig.1c), but these differ in their
aperture system.The Polystachyum-type is 6(～ 8)-zonocolpate , the Amphibium-type pantocolpate and
the Persicaria-type pantoporate.The aperture resembles that of the Aconogonon-type.The Aconogonon-
type has , however , an imperforate tectum with microspinules.
Pollen grains of the Polystachyum-type occur in the following species:P.pinetorum Hemsl., P.
570 中国科学技术大学学报 第 29 卷
polystachyum Wall ex Meisn , pollen grains of the Amphibium-type occur in the species P.
amphibium L.and pollen grains of the Persicaria-type occur in 36 species of Sect.Echinocaulon and
Sect.Persicaria.
Antenoron-type Pollen grains 12-pantocolpate or 30-pantocolpate spheroidal , 35.0 μm～ 62.5
μm in diameter.Equatorial view and polar view circular.Ectoaperture———colpus , 30-colpi sometimes
arranged as the edges of a pentagonal dodecahedron;12-colpi arranged as the edges of a cube.En-
doaperture———colpus , congruent with ectoaperture or absent.Exine 2.5 μm thick , sexine slightly
thicker than or equal to nexine.Ornamentation:finely reticulate.Sexine semitectate , columellate.
Pollen grains of the Antenoron-type occur in the following species:Antenoron filiform (Thunb.)
Roberty et Vautier , An.neofiliforme(Nakai)Hara.
Comments the Antenorpn-type is characterized by the arrangement of its colpi in regular pen-
tagous and by the fine reticulate ornamentation.The aperture resembles that of the Amphibium-type.
The Amphibium-type has , however , a coarse reticulate ornamentation.Pollen grains of the Amphibi-
um-type occur in the species Polygonum amphibium L.
Macranthum-type Pollen grains pantoporate , spheroidal , 42.5 μm ～ 75.0 μm in diameter.
Equatorial view and polar view circular.Ectoaperture———porus , usually 20 ～ 30 , circular.Endoaper-
ture———porus , more or less circular.Exine 4.0μm～ 5.5μm thick , sexine/nexine 2 ～ 4.Ornamen-
tation:granulates densely covered.Sexine intectate , the tectum is lost entirely and free , exposed
columellae exist as the sexine.Pollen grains of the Macranthum-type occur in the species P.
macranthum Meisn.
Comments The Macranthum-type is characterized by pantoporate and an intectate tectum with
free , exposed columellae existing as the sexine.This character is unique in the Polygonaceae of China.
Bistorta-type Pollen grains 3-zonocolporate , 30.6μm ～ 60.0μm×24.0μm～ 51.0μm , sub-
prolate-prolate (P/E=1.06 ～ 1.70).Equatorial view elliptic to slightly rectangular;polar view trian-
gular.Ectoaperture———colpus , narrow , their length c.1/3 ～ 3/4 of the polar axis.Endoaper-
ture———porus , circular.Exine variable in thickness.Columellae distinct , dense , longest at poes ,
branched in upper part of mesocolpium and at apocolpium.Ornamentation:granulate-perforate.Small
perforations in tectum largest at apocolpium.Pollen grains of the Bistorta-type occur in 10 species of
Sect.Bistorta.
Comments The Bistorta-type is characterized by its very variable columellae.The columellae in
the equatorial plane are usually simple , relatively short and crowded , but the increase considerably in
length towards the apocolpium where they are branched , coarse and more or less spread out widely.
The Bistorta-type resembles the Fagopyrum-type.They both have branched columellae , but in the
Fagopyrum-type all the columellae are branched and the ornamentation is finely reticulate.Pollen
grains of the Fagopyrum-type occur in 6 species of the genus Fagopyrum .
Avicularia-type Pollen grains 3-zonocolporate , 22.5 μm ～ 32.5 μm×15.3 μm ～ 25.0μm ,
subprolate-prolate(P/E=1.28 ～ 1.41).Equatorial view slightly rectangular;polar view circular or
triangular.Ectoaperture———colpus , long or rather long.Endoaperture———copus , lalongate or a nar-
571第 5期 Parallel Evolution of Aperture Numbers and Arrangement of Polygonaceae in China
row endocingulus;a circular mesoaperture usually present;costae endocingulus most distinct around
the mesoaperture.Exine 2.0 μm ～ 3.0μm thick , sexine slightly thicker than or equal to nexine.
Columellae indistinct.Ornamentation:granulate-foveolate.Pollen grains of the Avicularia-type occur
in 4 species of Sect.Avicularia.
Comments The Avicularia-type is characterized by its imperforate tectum , rectangular outline
in equatorial view and lalongate , tapering endocolpi , which are sometimes elongated into an endocin-
gulus.The Avicularia-type resembles the Convolvulus-type in some characters , but differs in having a
sexine which is usually thicker at the shoulders than in the mesocolpium and apocolpium.Another
difference is found in the endoaperture which in Avicularia-type is usually an endocolpus and only
sometimes a narrow endocingulus , whereas the endoaperture in Convolvulus-type is always a distinct
endocingulus.Moreover , in the SEM the surface around the ectocolpi lacks the characteristc margo of
granules.The Bistorta-type is also slightly rectangular in equatorial view , and has a closed tectum , but
it differs in the presence of branched columellae in the apocolpium and their larger size.
The Avicularia-type resembles the Plebium-type (fig.1d)in some characters , but the Plebium-
type is characterized by its imperforate tectum and distinctly thickened sexine at the shoulders of meso-
colpium and apocolpium.More importantly in the SEM in the Plebium-type , the microechinate is
around ectocolpi , and the smooth is inmesocolpium and apocolpium.Pollen grains of the Convolvulus-
type occur in the following species Polygonum convolvulus L., P.dentato-alatum F.Schm.ex Max-
im., P .dumetorum Linn.Pollen grains of the Plebium-type occur in the species:Polygonum
plebium R.Br.(fig.1d).
Auberti -type Pollengrains3-zonocolporate , 17.0μm ～ 20 .5μm ×15.3μm ～ 18.7μm ,
(a)P.auberti;(b)Pteroxygonum giraldii;
(c)Koenigia delicatula;(d)Rheum palmatum
Fig.2 Pollen grains of Polygonaceae species
subspheroidal-subprolate (P/E =1.08 ～ 1.22).
Equatorial view elliptical;polar view triangular.
Ectoaperture———colpus , rather long , slit-like.
Endoaperture———porus , lalongate.Exine c 2.0
μm thick , sexine equal to nexine.Columellae dis-
tinct , unbranched.Ornamentation:microechinate-
perforate.Pollen grains of the Auberti-type occur
in the species Polygonum auberti Linn.(fig.2a).
Comments the auberti-type is easily recog-
nized by its 3-zonocolporate and characteristic mi-
croechinate au over the pollen.Pollen grains of this
type resemble those of the convolvulus-type , but
differ mainly in their endoaperture and the distinct
ornamentation in their mesocolpium.
Pteroxygonum-type Pollen grains 3-zonocolporate , 62.9 μm ～ 69.7 μm ×49.3 μm ～ 62.9
μm , subprolate-prolate (P/E=1.22 ～ 1.41).Equatorial view oblong;polar view circular.Ectoaper-
ture———Colpus , rather long.Endoaperture———porus , outline circular , 8.5μm in diameter , margin
572 中国科学技术大学学报 第 29 卷
indistinct.Exine 5.1 μm thick , sexine/nexine 4.Ornamentation:finely reticulate.Lumina diameter
wider than muri width.Pollen grains of the Pteroxygonum-type occur in the species Pteroxygonum
giraldii Dammer et Diels.(fig.2b).
Comments The Pteroxygonum-type is easily recognized by its outline of subprolate-prolate and
distinctly wider lumina than muri.Pollen grains of this type resemble those of the Tiniaria-type in their
ectocolpi and ornamentation , but differ mainly in their bigger endopori.
Pollen grains of the Tiniaria-type occur in the following species Polygonum ciliinerve (Nakai)
Ohwi , P.multif lorum Thunb., P .nitens(Fisch.et Mey.)V.Petr.ex Kom., P.hypoleucum
Ohwi.
Cuspidatum-type Pollen grains 3-zonocolporate or 3-synzonocolporate , 25.0 μm～ 31.3μm×
22.5 μm～ 27.5μm , subspheroidal-subprolate (P/E=1.04 ～ 1.15).Equatorial view subcircular;
polar view circular.Ectoaperture———colpus , rather long.Endoaperture———porus , lalongate , wider
than colpus.Exine 2.5 μm thick , sexine slightly thicker than nexine.Columellae unbranched.Orna-
mentation:finly reticulate.Pollen grains of the Cuspidatum-type occur in the species P.cuspidatum
Sieb.et Zucc.
Comments The Cuspidatum-type are characterized by 3-zonocolporate or 3-synzonocolporate
pollen which has a finely reticulate ornamentation.The Cuspidatum-type resembles the Tiniaria-type in
their ectocolpi , size and , more or less , in their endoaperture.They both have finely reticulate orna-
mentation , but in the Cuspidatum-type , the ornamentation is prominently punctate-striate , and the
puncta is bigger under SEM.In the Tiniaria-type , the ornamentation is only finely reticulate , and the
puncta is smaller.
Sibiricum-type Pollen grains 3-zonocolporate , 22.5 μm ～ 31.3 μm ×21.3 μm ～ 27.5 μm ,
subprolate(P/E=1.06 ～ 1.25).Equatorial view subcircular;polar view circular.Ectoaperture———
colpus , rather long.Endoaperture———porus , lalongate.Exine 2.5 μm thick , uniform in thickness ,
sexine slightly thicker than or equal to nexine.Ornamentation:finely reticulate under LM;rugulate
under SEM.Pollen grains of the Sibiricum-type occur in the species Polygonum sibiricum Laxim.
Comments The Sibiricum-type is characterized by its 3-zonocolporate and having a rugulate or-
namentation.
Atraphaxis-type Pollen grains 3-zonocolporate , 22.1 μm ～ 28.9 μm×15.3μm ～ 27.2μm ,
prolate (P/E =1.18 ～ 1.56).Equatorial view elliptical;polar view circular.Ectoaperture———
colpus , rather long.Endoaperture———porus , lalongate.Exine 2.5 μm thick , sexine slightly thicker
than nexine , columellae well developed.Ornamention:striate-reticulate unde LM;prominently striate-
perforate under SEM.Pollen grains of the Atraphaxis-type occur in the following species Atraphaxis
manshurica , At.laetvirens.
Comments The Atraphaxis-type is characterized by its 3-zonocolporate and having a striate-
reticulate ornamentation.
Calligonum-type Pollen grains 3-zonocolporate , 29.0μm ～ 39.0 μm×25.0 μm ～ 30.5μm ,
subprolate-prolate(P/E=1.17 ～ 1.37).Equatorial view elliptical;polar view circular.Ectoaper-
573第 5期 Parallel Evolution of Aperture Numbers and Arrangement of Polygonaceae in China
ture———colpus , rather long.Endoaperture———porus , lolongate , wider than colpus.Exine 2.0 μm
thick , sexine equal to nexine , columellae well developed.Ornamentation:finely reticulate.Pollen
grains of the Calligonum-type occur in the species Calligonum mongolicum Turcz.
Comments The Calligonum-type is characterized by its 3-zonocolporate with bigger lolongate
endopori under the centre of the ectocolpus.The ornamentation is similar to that of the Tiniaria-type ,
but they differ in their outline of the endoporus.The Tiniaria-type is lalongate and smaller.
Delicatulum-type Pollen grains 7(or8)-zonocolpate , 22.1 μm ～ 25.5 μm (excl.spinules),
spheroidal.Equatorial view circular;polar view circular.Ectoaperture———colpus , arranged meridion-
ally;colpus membrane sometimes visible.Endoaperture absent.Exine 2.0 μm thick (except spin-
ules), sexine slightly thicker than nexine.Columellae indistinct.Ornamentation:prominently spinu-
lose.Pollen grains of the Delicatulum-type occur in the species Koenigia delicatula(Meisn.)Hara
(fig.2c).
Comments The Delicatulum-type is characterized by being 7(or8)-zonocolpate and having a
prominently spinulose ornamentation.This ornamentation is similar to that of the Forrestii-type and
Koenigia-type , but these differ in their apertural system.The Forrestii-type is pantocolpate and the
Koenigia-type pantoporate.
Pollen grains of the Forrestii-type occur in the following species Koenigia forrestii (Diels)
Mësiëek et Soják.Pollen grains of the Koenigia-type occur in the following species:K .islandica
Linn., K.cyanandra(Diels)Mësiëek et Soják , K.nepalensis D.Don.
Rheum-type Pollen grains 3-zonocolporate , 25.5 μm～ 30.6μm×23.8μm ～ 28.9 μm , sub-
spheroidal.Equatorial view elliptical;Polar view circular.Ectoaperture———colpus , rather long;col-
pus membrane not visible.Endoaperture———colpus , narrow , lalongate.Exine 2.0μm thick , sexine
slightly thicker than nexine.Ornamentation:finely granulate under LM;microechinate-perforate under
SEM , the punta connected by small striae.Pollen grains of the Rheum-type occur in the species
Rheum palmatum L.(fig.2d).
Comments The Rheum-type is characterized by being 3-zonocolporate and having a small , la-
longate endcolpus.Rheum-type is similar to those of Acetosa-type and Aquaticus-type in their size ,
shape and ornamentation , but they differ in their apertural system.The Rheum-type has a narrow la-
longate endocolpus , the Acetosa-type endoporus and the Aquaticus-type 9-pantocolporate.Pollen of
Oxyria digyna Hemsl.resembles that of Acetosa-type.Pollen grains of the Acetosa-type occur in the
following species:Rumex acetosa L., R .dentatus L.Pollen grains of the Aquaticus-type occur in
the species R .japonicus Houtt.
Homalocladium-type Pollen grains pantoporate , 30 μm , spheroidal.Pores usually 20 ～ 30 ,
circular , usually arranged disorderly.Porate membrane usually present , often besets with coarse
granules.Exine 2.0 μm thick , sexine equal to nexine.Ornamentation:granulate-perforate under
SEM.Pollen grains of the Homalocladium-type occur in the species:Homalocladium platycladium
(F.Muell.)Bailey.
Comments The Homalocladium-type is easily recognized by having large numbers of pores
574 中国科学技术大学学报 第 29 卷
(pantoporate)with distinct membrana pori and having a granulate ornamentation.
4 Evolutionary trend
According to the pollen evolutional model called `successiformy (Van Camp(5)), evolutionary
Fig.3 Parrel evolution of pollen of Polygonaceae in China
1 - Aconogonon hookeri;2 - A.campanulatum;3 - A.
pangianum;4 - Polygonum chinense var.dielsii;5 - P.
pinetorm;6-Antenoron fi liforme;7-Polygonum amphibium;8
- P. hastato-sagi ttatum;9 - P.macranthum;10 - P.
macrophyl lum ;11-P.patulum ;12-P.plebeium;13-P.
dumetorum;14-P.auberti;15-Pteroxygonum gira ldi i;16-
Polygonum mult iflorum;17-P.cuspidatum ;18-Fagopyrum
tataricum; 19 - Polygonum sibiricum; 20 - Atraphaxis
manshurica;21 - Calligonum mongolicum ;22 - Koenigia
delicatum;23 -K .forrest ii;24 -K..cyanandrum ;25 -
Rheum palmatum;26-Rumex dentatus;27-R.japonicus;28
-Homalocladium platycladium
trend is from 3-zonocolpate over 6(7 or 8)-zono-
colpate to dodecacolpate (30-pantocolpate)and
polyporate (pantoporate).In 28 pollen types ,
primitive 3-zonocolpate pollen types are Acono-
gonon-type and Cephalophilon-type.The evolu-
tionary trend in the structure of exine(Walker(6)
is atectate※tectate-imperforate※tectate-perforate
※semitectate※intectate , i.e.the evolutionary
trend in the ornamentation of exine microspinuu-
lose-foveolate ※microechinate-perforate ※striate-
punctate※finely reticulate※coarsely reticulate※
granulate (intectate).Aconogonon-type is evi-
dently the most primitive.According to the
pollen evolutionary trend in aperture and struc-
ture of exine , the 28 pollen types of Polygonaceae
in China have been arranged in the evolutionary
sequence , of which the 3-zonocolpate , tectate-
imperforate Aconogonon-type with the ornamenta-
tion of microspinules and foveolae has been con-
sidered the basic type from which types with
polycolcate and pantocolpate aperture ,with colpo-
rate and pantocolporate aperture , and with panto-
porate aperture have evolved along linear or par-
allel directions(fig.3).
Evolutionary trends of pollen types of Polyg-
onaceae in China have six parallel directions:
1)Aconogonon-type (3-zonocolpate , mi-
crospinulose-foveolate ) ※ Cephalophilon-type
(3-zonocolporate , coarsely reticulate ) ※
Polystachyum-type(6(-8)-zonocolpate , coarsely
reticulate)※Antenorpn-type(12 or 30-pantocolpate , finely reticulate)※Amphibium-type(30-pantocol-
pate , coarsely reticulate)※Persicaria-type (pantoporate , coarsely reticulate)※Macranthum-type (pan-
toporate , intectate).
2)Aconogonon-type (3-zonocolpate ,microspinulose-foveolate)※Bistorta-type (3-zonocolporate ,
575第 5期 Parallel Evolution of Aperture Numbers and Arrangement of Polygonaceae in China
granulate-perforate)※Avicularia-type(3-zonocolporate , granulate-foveolate)※Plebeium-type (3-zono-
colporate , granulate-foveolate-smooth)※Convolvulus-type (3-zonocolporate , microechinate or granu-
late-perforate-smooth)※Auberti-type (3-zonocolporate , microechinate-perforate)※Pteroxygonum-type
(3-zonocolporate , finely reticulate)or Tiniaria-type (3-zonocolporate , finelyreticalate)※Cuspidatum-
type (3-zonocolporate or 3-syncolporate , finely reticulate)※Fagopyrum-type(3-zonocolporate , finely
reticulate).
3)Aconogonon-type (3-zonocolpate , microspinulose-foveolate)※Sibiricum-type (3-zonocolpo-
rate , rugulate)※Atraphaxis-type (3-zonocolporate , striate-puntate)※Calligonum-type (3-zonocolpo-
rate , finely reticulate).
4)Aconogonon-type (3-zonocolpate , microspinulose-foveolate)※Campanulatum-type (6-panto-
colpate , microspinulose-foveolate)※Pangianum-type (12-pantoporate , microspinulose-foveolate).
5)Aconogonon-type(3-zonocolpate , microspinulose-foveolate)※Delicatulum-type(7(or8)-zono-
colpate , prominently spinulose)※Forrestii-type (12-pantocolpate , prominently spinulose)※Koenigia-
type (pantoporate , prominently spinulose).
6)Aconogonon-type (3-zonocolpate , microspinulose-foveolate)※Rheum-type (3-zonocolporate ,
microechinate-perforate)※Acetosa-type(3(or 4)-colporate , microechinate-perforate)※Aquaticus-type
(9(or 12)-pantocolporate , microechinate-perforate)※Homalocladium-type (pantoporate , granulate-
perforate).
In line 1 of evolution , according to the pollen evolutional model called `successiformy , polycol-
pate is derived from 3-zonocolpate , i.e.Polystachyum-type from Cephalophilon-type.It appears that
the finely reticulate is more primitive than the coarsely reticulate , i.e.Antenorpn-type※Amphibium-
type※Persicaria-type , and semitectate more primitive than intectate , i.e.Persicaria※Macranthum-
type.All the types except the Antenorpn-type include Polygonum spp.The affinity among the
Cephalophilon-type , Polystachyum-type , Amphibium-type and Persicaria-type is that all the types have
the same semitectate reticulate exine surface sculpturing pattern.The affinity between Antenorpn-type
and Amphibium-type is that both show the same pentagonal arrangement of colpi.Antenoron
neofi liforme usually has 30-pantocolpate pollen grains , but sometimes 12-pantocolpate pollen grains are
found on the same specimen.It provides an intermediate between 6(7 or 8)-zonocolpate and 30-pan-
tocolpate pollen grains.
In line 2 of evolution , finely reticulate exine appears more advanced than perforate exine , i.e.
Pteroxygonum-type is derived from Auberti-type.All the types except the Pteroxygonum-type and
Fagopyrum-type include Polygonum spp.The Pteroxygonum-type includes only the Pteroxygonum
giraldii , and the Fagopyrum-type the genus Fagopyrum ssp.
In line 3 of evolution , the Sibiricum-type is not directly related to Atraphaxis-type and
Calligonum-type.The Sibiricum-type includes Polygonum , whereas the Atraphaxis-type and
Calligonum-type belong to the tribe Atraphaxideae.The affinity between sibiricum-type and Atraphaxis-
type is that their ornamentation closely resembles.Strate-punctate is more primitive than finely reticu-
late , i.e.Sibiricum-type※Atraphaxis-type※Calligonum-type.
576 中国科学技术大学学报 第 29 卷
In lines 4 , 5 , 6 of evolution , each evolutionary line shows evidently affinity.The affinity among
the Aconogon-type , Campanulatum-type and Pangianum-type is that they have the same microspinu-
lose-foveolate ornamentation;the affinity among the Delicatulum-type , Forrestii-type and Koenigia-type
is that they share the same prominently spinulose ornamentation , and the affinity among the Rheum-
type , Acetosa-type , Aquaticus-type and Homalocladium-type is microechinate-perforate or granulate-
perforate.The Aconogon-type , Campanulatum-type and Pangianum-type belong to the genus
Aconogonon , the Delicatulum-type , Forrestii-type and Koenigia-type the genus Koenigia , and the
Rheum-type , Acetosa-type , Aquaticus-type the tribe Rumiceae.All the three evolutionary lines follow
the pollen evolutionary model called`successiformy .
References
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the relationship of the Plumbaginaceae , Polygo-
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[ 2] Hedberg O.Pollen morphology in the genus
Polygonum L.S.Lat.and its taxonomical signifi-
cance.Sven.Bot.Tidskr., 1946 , 40:371—404
[ 3] Wang Jianxin , Feng Zhijian.A study on the
pollen morphology of the genus Polygonum in Chi-
na.Acta Phytotaxonomica Sinica , 1994 , 32(3):
219—231
[ 4] Hong S P , Hedberg O.Parallel evolution of aper-
ture numbers and arrangement in the genera
Koenigia , Persicaria and Aconogonon Polygo-
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[ 5] Van Campo M.Patterns of pollen morphological
variation within taxa.In:The evolutionary signifi-
cance of the exine (ed.I.K.Ferguson and J.
Muller), 1976 , 125—137
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1974 , 61:891—902
中国蓼科花粉萌发孔的平行进化
周忠泽 鲁润龙 郑艳燕
(中国科学技术大学生命科学学院)
摘要 利用光学显微镜和扫描电镜对蓼科 12属 111种的花粉进行了观察和研究 ,划
分出 28个花粉类型 ,对每个类型做了精确的描述和评价;提供了每个花粉类型的重
要鉴别特征.根据花粉的萌发孔 、外壁结构 、外壁纹饰 、形状及大小的演化趋势 ,讨论
了各类型花粉的亲缘关系 ,构建了它们的系统演化路线图谱.该项研究不仅为化石花
粉的研究提供了鉴定依据 ,而且为中国蓼科孢粉地理学的研究提供了理论基础.
关键词 平行演化 ,花粉 ,蓼科 ,中国
中图法分类号 Q949.744
577第 5期 Parallel Evolution of Aperture Numbers and Arrangement of Polygonaceae in China