全 文 ：假瘤蕨属植物配子体与幼孢子体发育的比较形态学研究*
邵摇 文1,2, 陆树刚2
(1 上海辰山植物园, 中国科学院上海辰山植物科学研究中心, 上海摇 201602;
2 云南大学生态学与地植物学研究所, 云南 昆明摇 650091)
摘要: 配子体及幼孢子体发育过程对蕨类植物的系统学研究具有重要意义, 但在假瘤蕨属植物中较少报
道。 本研究比较了 3 种假瘤蕨属植物的配子体及幼孢子体发育过程: 孢子均为单裂缝, 萌发类型为书带蕨
型。 原叶体发育为槲蕨型。 丝状体 2 ~ 6 细胞, 成熟配子体心形, 中肋明显加厚。 配子体两性, 在播种后
48 ~ 55 d产生精子器, 之后 15 ~ 18 d产生颈卵器。 播种后 80 ~ 100 d, 形成胚胎, 后者分化出第一叶、 第
一根和茎端, 发育为幼孢子体。 配子体边缘分布有单细胞毛状体, 配子体腹面分布有单列多细胞的毛状
体, 以中肋处最多, 围绕并保护胚胎和幼孢子体。 本属 3 个种的配子体和幼孢子体, 在孢子体积、 萌发时
间、 丝状体和成熟配子体特征以及性器产生时间等方面存在差异。 土培条件下的配子体发育不同步, 即配
子体分批发育, 原因为配子体的营养繁殖或孢子萌发不整齐。
关键词: 配子体; 幼孢子体; 假瘤蕨属
中图分类号: Q 944摇 摇 摇 摇 摇 摇 摇 文献标识码: A摇 摇 摇 摇 摇 摇 摇 文章编号: 2095-0845(2013)04-522-07
Comparative Morphology of Development of the Gametophyte
and Juvenile Sporophyte of Phymatopteris*
SHAO Wen1,2, LU Shu鄄Gang2
(1 Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, Shanghai Chenshan Botanical Garden,
Shanghai 201602, China; 2 Institute of Ecology and Geobotany, Yunnan University, Kunming 650091, China)
Abstract: The development of the gametophyte and juvenile sporophyte are important in the systematics of fern
groups, yet have been seldom studied in the genus Phymatopteris. Three species of Phymatopteris are described and
compared in the present paper. It was established that spores were monolete, germination was Vittaria鄄type, and
prothallial development was Drynaria鄄type. Germ filaments developed 2-6 cells, and mature prothalli were cordate
with prominent cushions in the middle of two wings. Prothalli were usually bisexual. Antheridia were produced 48-
55 days after sowing, and archegonia formed 15-18 days after the production of antheridia. Embryos began to devel鄄
op in the cushion of the gametophyte 80-100 days after sowing. Spherical embryos differentiated into the first leaf,
the first root, and shoot apex, and then into the juvenile sporophyte. Unicellular hairs appeared on the margin of
prothalli and multicellular uniseriate trichomes developed on the dorsal surface of prothalli, especially in the cush鄄
ion, to surround and protect the embryo and juvenile sporophyte. Differences in size of spores, germination time,
characteristics of the filaments and adult prothallus, and time of gametangia formation were documented among the
three species. Gametophytes in soil medium usually grew asynchronously, which may have been caused by vegetative
generation or asynchronous germination of spores.
Key words: Gametophyte; Juvenile sporophyte; Phymatopteris
植 物 分 类 与 资 源 学 报摇 2013, 35 (4): 522 ~ 528
Plant Diversity and Resources摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 摇 DOI: 10. 7677 / ynzwyj201312132
* Foundation item: The National Natural Science Foundation of China (31200162)
Received date: 2012-10-28, Accepted date: 2013-03-01
作者简介: 邵摇 文 (1979-) 女, 博士, 主要从事蕨类植物系统分类学研究。 E鄄mail: shaowen19792005@ 163. com
摇 Phymatopteris Pichi鄄Serm. is a derived Polypo鄄
diaceous fern distributed mainly in the mainland of
Asia. It is characterized by simple, trifid, palmati鄄
fid, pinnatifid fronds of usually chartaceous texture,
glaucous underneath, by the single鄄rowed but usual鄄
ly superficial or slightly immersed large sori and by
also the drynarioid type of venation (Ching, 1964).
The reports on taxonomy ( Shao and Lu, 2009 ),
spore ornamentations (Shao et al., 2010a), leaf ap鄄
pendages ( Shao et al., 2010b), leaf epidermises
(Shao et al., 2011a), and characters of scales (Shao
et al., 2011b) of Phymatopteris have been done.
As the raw materials of Chinese medicinal herbs,
some species of Phymatopteris were severely lacking in
the field, such as P. engleri, P. hastata, P. conjuncta,
and P. griffithiana (Wu, 1988). It忆s necessary to ex鄄
plore and study the spores breeding of Phymatopteris,
especially the gametophyte and juvenile sporophyte.
Moreover, gametophyte characters, such as the early
development, mature form, hairs, and gametangia
were considered to be systematic significance (Atkin鄄
son and Stokey, 1964; Nayar and Kaur, 1971). Com鄄
parative morphology of the fern gametophyte will give
more information to understand the phyletic groups
(Bower, 1923-1928). Few researches on the gameto鄄
phyte of Phymatopteris were reported, included Nayar
and Kaur (1971) and Atkinson (1973). This paper
presented a more detailed study on the development
of gametophyte and juvenile sporophyte and to assay
its systematic evoultionary patter in Phymatopteris.
1摇 Materials and methods
Spores of Phymatopteris were collected in Au鄄
gust 2008 and the voucher information was listed in
the appendix. Specimens were deposited in the Her鄄
barium of Yunnan University (PYU).
Spores were sown in three different media: im鄄
proved Knop爷s agar medium (Liu et al., 1991), a
soil medium (Shao et al., 2007) and distilled wa鄄
ter. Before sowing, the spores were sterilized with
4% sodium hypochlorite for five minutes, then
rinsed with sterilized water four times; between rin鄄
ses spores were centrifuged at 3 000 rpm five times.
All cultures were kept at 20 依 3 益 under a 12 h
photoperiod, a photon flux density of 50 mmol·m-2·
s-1, which was provided by cool white florescent
tubes and a 90% relative humidity.
2摇 Results
The characteristics of the development of game鄄
tophyte and juvenile sporophyte were listed in Table
1. The data of spores germination and the filamen鄄
tous phase were from the spores sowing in distilled
water and Knop爷s agar medium for easily manipu鄄
late. The data of other phases were from the spores
sowing in soil medium.
Spore
Spores of three species were monolete. Germi鄄
nation was Vittaria鄄type in the three species. Spores
in distilled water and improved Knop爷s agar medium
began to germinate between 2-5 days after sowing,
while in soil medium, the spores were found to ger鄄
minate 2 days later than those in distilled water and
improved Knop爷 s agar medium. The first rhizoid
was ruptured from the linear scar firstly in three spe鄄
cies (Fig. 1: 1-4). The first prothallial cell was o鄄
val, which divided to a uniseriate filament.
Filamentous phase
The first prothallial cells of three species sowing
in improved Knop爷s agar medium underwent longitu鄄
dinal divisions to 2 - 4 cells long, uniseriate fila鄄
ments ( Fig. 1: 5 -10), while emerged in distilled
water, the filaments were 3-8 cells long (Fig. 1: 11
-12). After several divisions, filaments produced
the spatulate plate with the Drynaria鄄type of prothal鄄
lial development.
Spatulate phase
The spatulate plates were formed between 24-
30 days after sowing in soil medium (Fig. 1: 13 -
15 ). After several divisions of the meristematic
cell, the meristematic zone was formed ( Fig. 1:
16), which often presented as an apical notch. The
wings of the prothallus were asymmetric sometimes,
which would become symmetric gradually.
3254 期摇 摇 SHAO and LU: Comparative Morphology of Development of Gametophyte and Juvenile Sporophyte of Phymatopteris 摇 摇
Table 1摇 Comparison of different stages of the prothallial development and juvenile sporophyte in Phymatopteris
P. griffithiana P. rhynchophylla P. oxyloba
Spores
Size 45(48)50伊26(28)33 滋m2 40(43)45伊22(25)30 滋m2 45(48)52伊28(30)33 滋m2
Germination 2days after sowing (Fig. 1: 1, 4) 3days after sowing (Fig. 1: 2) 5days after sowing (Fig. 1: 3)
Filamentous phase Long filaments (2-6 cells)(Fig. 1: 7, 8, 11, 12)
Short filaments (2-4 cells)
(Fig. 1: 5, 9)
Short filaments (2-4 cells)
(Fig. 1: 6, 10)
Spatulate phase Long spatulate Short spatulate (Fig. 1: 14-15) Long spatulate (Fig. 1: 13)
Mature prothallus
Meristematic zone Active division Active division Active division, few hairs (Fig. 1: 16)
Gametangia (diameter)
Antheridium 42. 2-48滋m (Fig. 1: 18) 40. 8-45滋m (Fig. 1: 19) 40. 2-44滋m (Fig. 1: 17)
Archegonium 45. 2-48. 4滋m 44. 2-48. 6滋m (Fig. 1: 20) 41. 2-50. 4滋m
Hairs Unicellular Unicellular (Fig. 2: 23) Unicellular (Fig. 2: 21-22)
Trichomes Multicellular (Fig. 2: 32-33, 36) Multicellular (Fig. 1: 20) Multicellular
Rhizoid Normal, bended or forked sometimes(Fig. 2: 27-28) Normal (Fig. 2: 29)
Normal, bended or forked sometimes
(Fig. 2: 24-26)
Marginal cell Rectangle, few hairs on apex Rectangle, few hairs Rectangle, few hairs (Fig. 2: 30)
Shape Cordate, border than long(Fig. 2: 37-38) Cordate, border than long
Cordate, border than long
(Fig. 2: 39)
Embryo Formed in 88days after sowing(Fig. 2: 32-33) Formed in 98days after sowing
Formed in 85days after sowing
(Fig. 2: 31)
Juvenile sporophyte Sole every prothallus (Fig. 2: 35-36) Sole every prothallus Sole every prothallus (Fig. 2: 34)
Mature prothallus
With the active division of meristematic cell,
spatulate phase prothallus developed to a adult proth鄄
allus, which began to produce antheridia and arche鄄
gonia, and then differentiated to mature prothallus.
Gametangia—The prothalli were bisexual al鄄
though the antheridia and archegonia occurred on
each prothallus asynchronously.
Prothalli began to produce antheridia 48 - 55
days after sowing in soil medium. Antheridia were
distributed over the dorsal surface or along the margin
(Fig. 1: 17-18). The mature globose antheridia were
about 40. 2-48 滋m in diameter. Once the mature an鄄
theridium was watered, the opercula cells were shed
to release spermatozoids (Fig. 1: 19).
The archegonia were accompanied with cushion
appearance, and formed in a group near the notch of
the prothalli, 15-18 days later than the appearance
of antheridia. The diameter of archegonium was 45. 2-
50. 4 滋m from the top view (Fig. 1: 20).
Hair—Gametophyte hairs appeared on the mar鄄
gin of prothallus. Hairs were unicellular, which
measured approximately 20-30 滋m long or much lon鄄
ger by 15 滋m wide at the base (Fig. 2: 21-23).
Trichome—Multicellular uniseriate trichomes
appeared on the cushions as archegonia had formed.
Therefore, they surrounded and protected the embryo
and juvenile sporophyte (Fig. 1: 20, Fig. 2: 32-33).
Rhizoid—Rhizoids grew from the rhizoid ini鄄
tials or the basal cells of the filaments while the pri鄄
mary rhizoids elongated (Fig. 2: 29). The number
of the rhizoids increased with the development of the
prothallus. Forked (Fig. 2: 24, 26, 28) or bended
(Fig. 2: 25, 27) rhizoids occurred constantly.
Marginal cell—The marginal cell of prothallus
was irregular rectangle or trapezoid, which contained
lots of chloroplasts (Fig. 2: 30).
Embryo
Embryo began to develop in the cushion of ga鄄
metophyte 80-100 days after sowing in soil medium
(Fig. 2: 31-32). Spherical embryo 50-150 滋m in
diameter, and differentiated the first leaf, the first
root, and shoot apex, and then formed the juvenile
sporophyte (Fig. 2: 33).
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Fig. 1摇 1-20. The Development of Gametophyte and Juvenile Sporophyte of Phymatopteris. 1-4. Spore germination; 5-12. Filaments; 13
-14. Spathulate phase prothallus (28 days); 15. Spathulate phase prothallus (30 days); 16. Asymmetric cordate prothallus, show meris鄄
tematic zone (38 days); 17-19. Antheridia (50-58 days); 20. Top view of adult archegonium and multicellular trichomes (70 days)
P. griffithiana (1, 4, 7-8, 11-12, 18); P. rhynchophylla (2, 5, 9, 14-15, 19-20); P. oxyloba (3, 6, 10, 13, 16-17).
An. Antheridium; Ar. Archegonium; T. Trichomes
5254 期摇 摇 SHAO and LU: Comparative Morphology of Development of Gametophyte and Juvenile Sporophyte of Phymatopteris 摇 摇
Fig. 2摇 21-39. The Development of Gametophyte and Juvenile Sporophyte of Phymatopteris. 21-23. Prothallial juvenile hairs (34 days) .
24-29. Rhizoids (40-42 days) . 24. Forked. 25. Bended. 26. Tip鄄forked. 27. Bended. 28. Forked. 29. Normal. 30. Marginal cell of
adult prothallus (40 days). 31. Mature prothallus, show MZ and E (88 days). 32. Spherical embryo in the mature prothallus (90 days). 33
-36. Juvenile sporophyte, show SA, FL, SL, and TL (98-108 days). 36. Enlarged figure 35. 37. Mature prothallus (80 days). 38. Top
view of mature prothallus, show FL and the VS (104 days). 39. Adult prothallus, show the asynchronous development (80 days)
P. griffithiana (27-28, 32-33, 35-38); P. rhynchophylla (23, 29); P. oxyloba (21-22, 24-26, 30-31, 34, 39)
Ch. Chloroplast; E. Embryo; FL. The first leaf; H. Hair; Mz. Meristematic zone; Rh. Rhizoid; SA. Shoot apex;
SL. The second leaf; T. Trichomes; TL. The third leaf; VS. Vascular strand
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Juvenile sporophyte
Mature prothalli raise sporophytes 2 -3 months
after sowing. Embryo differentiated the first leaf ear鄄
lier than the first root. After the development of the
second leaf, the vascular strand reached to the first
leaf (Fig. 2: 34 -35, 36 -38). We observed more
multicellular hairs surrounded the embryo ( Fig. 2:
32-33), and then protected juvenile sporophyte.
We found that the gametophyte developed asyn鄄
chronously in Phymatopteris oxyloba: after the game鄄
tophytes mature, another batch of small gameto鄄
phytes began to grow (Fig. 2: 39). This phenome鄄
non has been found in Lygodium japonicum (Shao et
al., 2007) and Sphaeropteris brunoniana (Chen et
al., 2008a, b).
3摇 Discussion
Nayar and Kaur (1971) reported that the spore
germination of Phymatopteris is of the Vittaria鄄type
(Fig. 3: a鄄e) and prothallial development is of the
Drynaria鄄type (Fig. 3: f鄄l) . The filaments are often
more slender than that in other Polypodiaceae. The
antheridium is small, sub鄄globose, with a saucer鄄 or
cup鄄shaped basal cell (Fig. 3: n). Sex organs are
of the common Leptosporangiate鄄type. Atkinson
(1973) reported the marginal鄄rhizoids (Fig. 3: m)
in the prothallus of Phymatopteris taeniata. The re鄄
sults of Nayar and Kaur in 1971 were supported by
the characteristics of germination and prothallial de鄄
velopment type in this work.
Phymatopteris is a higher leptosporangiate fern
genus in Polypodiaceae, with the typical develop鄄
mental process and evolved characteristics of game鄄
tophyte in this paper. The characteristics of hairs in
this study was similar to the ones in Phymatosorus
hainanensis in Polypodiaceae ( Xu et al., 2005).
While the multicellular trichomes surrounded and
protected the embryo and juvenile sporophyte were
rarely reported for gametophyte of Polypodiaceae,
which we believed as a evolved characteristics of ga鄄
metophyte. We supported the result that embryo dif鄄
ferentiated the first leaf earlier than the first root in
Phymatopteris, which was similar to the result of Ly鄄
godium japonicum in Shao et al. (2007).
Different media and the sowing density would
affect the development of gametophyte. Atkinson and
Stokey (1964) found that more male prothalli grow in
crowded solid medium, and bisexual prothalli appear
Fig. 3摇 Diagram of Vittaria鄄type spore germination (a鄄e), Drynaria鄄type prothallial development ( f鄄l), marginal rhizoids (m),
and antheridium with basal cell (n) in Phymatopteris. Based on Nayar and Kaur (1971), and Atkinson (1973)
7254 期摇 摇 SHAO and LU: Comparative Morphology of Development of Gametophyte and Juvenile Sporophyte of Phymatopteris 摇 摇
in the medium with adequate nutrition and light, as
well as the moderate density. We confirmed the
point of Atkinson and Stokey (1964), by finding
most lingulate male prothalli in improved Knop爷 s
agar medium and distilled water, also in crowded
soil medium, whose meristematic zone and archego鄄
nia were delayed. And archegonial prothalli were
mostly grew on the sparse soil medium, earlier and
much more than in improved Knop爷s agar medium;
never grew on distilled water.
The asynchronous development in Sphaeropteris
brunoniana was because of vegetative generation
(Chen et al., 2008a, b), which do not supported
by our results. We have another explanation that the
spores of Phymatopteris oxyloba maybe germinated a鄄
synchronous, for the second batch of gametophytes
do not attach to the older prothallus in most case.
Therefore, the asynchronous development in fern ga鄄
metophytes need further investigated.
Appendix
P. griffithiana (Hook. ) Pichi鄄Serm. China: Yunnan,
Pianma, Shao W. 001
P. oxyloba (Wall. ex Kunze) Pichi鄄Serm. China: Yun鄄
nan, Xinping Mt. Ailaoshan, Shao W. 013
P. rhynchophylla ( Hook. ) Pichi鄄Serm. China: Yun鄄
nan, Pingbian, Mt. Daweishan, Shao W. 029
Acknowledgements: We would like to thank Prof. R. X.
Wang for assistance on the experience. The first author would
also thank Prof. Damian Shea of North Carolina State Univer鄄
sity and Prof. Jerry Li for helpful suggestions and critical
reading of the manuscript.
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