MORPHO-ANATOMIC FEATURES AND CHEMICAL COMPOUNDS IN

SOME AQUATIC PLANT SPECIES – PRELIMINARY DATA

Emilia Brîndu a S NDULESCU, Mala-Maria STAVRESCU-BEDIVAN, Gina VASILE SC E EANU, Tudor CHIOPU

University of Agronomic Sciences and Veterinary Medicine of Bucharest, Faculty of Agriculture

59 Marasti Blvd, District 1, 011464, Bucharest, Romania

Corresponding author email: emasand@yahoo.com Abstract Plants live everywhere, populating all major habitats (air, land, water). Their life cycle takes place under the influence of environmental factors and is therefore subject to large variations in abiotic factors. In this context, plants have changed over time their structures, organ shape and appearance, resulting from their adaptation to living environment. Some changes in the structure and function of the vegetative organs, arising as a result of their adaptation to the plant were followed by one of the greatest figures in literature and the founder of morphology as a science – J.W. von Goethe, who in 1790 formulated a theory of plant metamorphosis (adaptive change). This paper highlights such adaptive changes but seeks and identifies chemical elements in plant composition under study (Hydrocharis morsus-ranae, Anubias barteri, Hygrophila odora, Bacopa caroliniana) – the first step in trying as thorough knowledge of aquatic plants to establish their possible uses. Key words: aquatic plants, metamorphosis, chemical elements. INTRODUCTION The aquatic plants can live underwater (submerged) or can float on water surface (natant). Some of them have adapted their morphology to aquatic environment: large intercellular spaces in lamina are connected with aeriferous canals from petiole that extend as aerenchyma in the rhizome and roots, ensuring their oxygenation. Other plant species compensate the underdeveloped aerenchyma by highlighting the mechanical and conducting tissues. The aim of thus study was to investigate the morpho-anatomic features and chemical compounds in the following aquatic plant species: Hydrocharis morsus-ranae, Anubias barteri, Hygrophila odora, Bacopa caroliniana. Hydrocharis morsus-ranae (Alismatales, Hydrocharitaceae) or frogbit, native to Europe and parts of Asia, is a free-floating annual herbaceous aquatic plant, but its leaves can become emergent when the vegetation is dense enough (O’Neil, 2007). Anubias barteri (Alismatales, Araceae), a West African species, survives either totally or

partially submersed (http://www.liveaquaria.com/). The Hygrophila species usually are growing emersed along natural bodies of water (http://naturalaquariums.com/). Hygrophila odora (Lamiales, Acanthaceae) is a plant species distributed in Western Africa; its emersed form has a strong, ascending to upright stems that lignify at the basis, and lanceolate leaves (http://www.flowgrow.de/db/aquaticplants/). Bacopa caroliniana (Lamiales, Scrophulariaceae) comes from South America, where it is found growing in swampy areas, emerged and submerged. One of the basic characteristics of this plant is lemon smell of the leaves when they are broken (www.aquascaping.ro). MATERIALS AND METHODS For identification and description purposes, we used preserved material belonging to four aquatic plant species: Hydrocharis morsus-ranae, Anubias barteri, Hygrophila odora, Bacopa caroliniana. Macroscopic observations were performed on plants with the help of identification handbooks. Microscopic

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Scientific Papers. Series A. Agronomy, Vol. LVII, 2014ISSN 2285-5785; ISSN CD-ROM 2285-5793; ISSN Online 2285-5807; ISSN-L 2285-5785

observationwere madestudied plaObservatioIOR microBiology, Utaken withDMC - LSSodium anby flame (extractant RESULTS Results regof aquatic(frogbit) Hydrocharnatant hydstolons andleaves. It flowing wa

Figure Hydrocharepidermis covered wi

Figure 2. H

Fundamenthaving manThe mechais limited vessel. Tissue dimranae leaf’

ns and mie on numerants (Andreions were caoscope belonUASVM Buh the digital

60 (6MPX,nd potassium

photometryt ratio 1:20)

S AND DIS

garding moc plant Hy

ris morsus-drophyte pld long-petiois commo

aters.

1. Hydrochari

ris morsus-rformed fro

ith a thin cu

Hydrocharis msection

tal parenchny aerifer canical elemand the wo

mensions fr’s petiole ar

icrometric rous cross-si, 2003). arried out wnging to th

ucharest. Thcamera Pan

, 3X opticalm levels wey, using 2.

SCUSSION

orpho-anatoydrocharis

-ranae (Filant. It hasolate, ovate on in stagn

is morsus-ran

ranae leaf’som a singleuticle (Figur

morsus-ranaen (original)

hyma is highchannels of vents are red

ood is reduc

rom Hydrocre shown in

measuremesections of

with a ML-e laboratoryhe photos wnasonic Lum zoom). ere determi% acetic a

NS

omic structmorsus-ra

igure 1) is long, slenkidney-sha

nant or slo

nae (original)

s petiole hase row of cere 2).

e: petiole cross

hly developvarying sizeduced. Phloced to a sin

charis morsTable 1.

ents the

-4M y of

were mix

ined acid

ture anae

s a nder aped wly

s an ells,

s-

ped, es. oem ngle

sus-

Tab

NR123

Hywitpreand

F

Thelonidiointr(FiTheBetcollamTismo

NR123

Resof a AnufouIn exoaer

ble 1. Tisues mto H

R. Cortex Con

drocharis mth a dorsesenting a md lower epid

Figure 3. Hydr

e mesophylng cells, roblasts. Tracelular gure 3). e ribs presetween ribs lenchyma mina’s resistssue’s leaforsus-ranae

Table 2. Tisumo

R. Up Lo

sults regardaquatic plan

ubias barteund in aquarcross sectio

odermis, corenchyma ti

measurement fHydrocharis m

TISSUE Epidermis

x, Central cylinducting fasci

morsus-ranaiventral he

mesophyll tisdermis (Figu

rocharis mors(origin

ll presents arich in ch

The lacunaspaces (a

ent a very wand lower is differe

tance. f dimensioplant are in

ues measuremorsus-ranae le

TISSUE pper epidermiMesophyll

ower epidermi

ding morphnt Anubias b

ri (Figure 4riums. on, the adveortex and vssues are di

from leaf petimorsus-ranae

M

inder icle

ae has a beterofacial, ssue lie betwure 3).

sus-ranae : leanal)

a palisadic hloroplasts ar tissue aeriferi pa

weak develoepidermis,

entiated, t

ons in Hndicated in T

ments from Hydeaf structures

Mis

is

ho-anatomibarteri

4) is a plant

entitious rovascular cyifferentiated

ole belonging

MEAN (μ) 72

2448 216

bifacial leafstructure,

ween upper

af structure

tissue withincludinghas big,

arenchyma)

oped xylem.an angular

that gives

HydrocharisTable 2.

drocharis

MEAN (μ) 28.8 360 57.6

ic structure

t commonly

oot presentsylinder. Nod.

g

f , r

h g , )

. r s

s

e

y

s o

442

Fi

In the vasphloem velignificatedpith contai

Figure 5. C

Dimensiontissues are

Table 3. T

NR. 1 2 3 4 5

Table 4. Tisu

NR. 1 2 3 4

igure 4. Anubi

scular cylinessels alterd cells betwns lignifica

Cross section (o

ns recorded shown in T

Tisues measure

TISSUExoderm

CorteEndoder

Vascular cyPith

ues measuremto Anu

TISSUECuticle

EpidermConducting fa

Sclerenchy

ias barteri (or

nder (Figurernates with

ween those tated cells.

through Anubriginal)

for Anubias

Table 3.

ements from Aroots

UE mis

ex rmis ylinder

h

ment from leaf ubias barteri E e

mis fascicle yma

riginal)

e 5) numerh xylem, wtwo layers. T

bias barteri ro

s barteri ro

Anubias barte

MEAN (28.857614.4

662.4360

petiole belong

MEAN (μ14.4 28.8 57.6 72

rous with The

oot

ot’s

eri

(μ)

ging

μ)

In unicutdevsclpetmicare

Fig

Thewita vlowsiz

Thesevsparichbun7). meTab

cross-sectioistratified eticle. The coveloped; pherencyma ctiole being crometric m

e indicated i

gure 6. Cross-

e leaves arth pinnate v

very thin cutwer epiderme) (Figure 7

Figure 7. Cr

e mesophylveral rows aces. Rows h in chlorondles surro

Dimensioeasured inble 5.

on (Figure 6epidermis, ortical parenhloem and caps) are di

polistelic. measuremenn Table 4.

-section througbarte

re large, grvenation. In ticle, upper

mis (formed7).

oss section thr

ll is homogof cells below the

oplasts. Thunded by ns recordeAnubias b

6), leaf’s pecovered wnchyma is v

xylem veisorderly ar

The tissunts in Anub

ugh petiole beleri

reen, ovatecross sectioepidermis,

d by cells o

hrough a A. ba

geneous, cowithout i

e upper epihe ribs havsclerenchym

ed for leabarteri are

etiole has awith a thinvery poorlyssels (with

rranged, theue’s petiolebias barteri

longing to A.

-lanceolate,on, presentsmesophyll,

of different

arteri leaf

onsisting ofntercellularidermis areve vascularma (Figureaf’s tissues

shown in

a n y h e e i

, s , t

f r e r e s n

443

Table 5. Tissue dimensions in Anubias barteri leaves

NR. TISSUE MEAN (μ) 1 Cuticle 14.4 2 Upper epidermis 72 3 Mesophyll 316 5 Lower epidermis 28.8 6 Midrib 144

Results regarding morpho-anatomy of Hygrophila odora aquatic plant Hygrophila odora (Figure 8) is an aquatic plant species.

Figure 8. Hygrophila odora (original)

The cylindrical stem has nodes and internodes, with dorso-ventral flattened, pinnate leaves in nodes. It forms adventive roots. In cross-section, the root appears to be formed by rhizodermis lacking absorbing hairs (one layer of cells); cortex is very well developed, with large intercellular spaces found in aerenchyma (Figure 9).

Figure 9. Hygrophila odora: root cross section (original) The mechanical elements and central cylinder are very reduced (Figure 9). The dimensions for measured tissues in Hygrophila odora root are indicated in Table 6. The stem has a unistratified epidermis, covered by a thin cuticle (Figure 10).

Table 6. Tissue dimensions from Hygrophila odora roots

NR. TISSUE MEAN (μ) 1 Rizhodermis 28.8 2 Cortex 244.8 3 Central cylinder 115.2

Figure 10. Hygrophila odora: cross section of a cortex

(original) In the highly developed cortex, there are three or four layers of colechyma but the major part is occupied by aerenchyma with intercellular spaces by different sizes (Figure 10), forming air chambers. The last layer of the cortex, endodermis, is formed by one single row of different size cells.

Figure 11. Hygrophila odora: cross section of a central

cylinder (original) The conducting tissue is formed by poor developed collateral fascicles, orderly arranged (Figure 11). The dimensions for measured tissues in Hygrophila odora stem are shown in Table 7. In cross section, the leaf of Hygrophila odora presents the upper epidermis with smaller cells on one single row, covered by a thin cuticle and the lower epidermis formed by bigger cells (Figure 12).

444

Table 7. M

NR . 1 2 3 4 5 6 7 8

Figure 12

Below thepresenting (Figure 12)air chambeThe ribs arfor measuleaves are p

Table 8. T

NR. 1 2 3 4

Results regof aquatichyssop) Bacopa c(Figure 13)years. In stem’s leaves (oblIn cross-serhizodemisand centrhizodermicortex hasintercellulalayer of differentiat

easurements fo

TISSCutic

EpiderCort

EndodeCollenc

PithCentral c

Conducting

2. Hygrophila (o

e upper epcells

), and it is ers. re poorly deured tissuepresented in

Tissue dimensl

TISSUpper epLower ep

MesopRib

garding moc plant Ba

caroliniana), ubiquitou

nodes therelong, succulection, the s, exodermtral cylindis is lackins cells withar spaces the cortex

ted, present

for stem tissueodora

UE cule rmis tex ermis chyma h

cylinder g fascicle

odora: cross riginal)

pidermis, thrich in crossed by

eveloped. Tes in Hygrn Table 8.

ions from Hygleaves SUE pidermis pidermis phyll b

orpho-anato

acopa carol

is an us in aquari

e are advenlents, oppos

adventive mis, corticader (Figurng in absorh thin cell

(aerenchymx, endoderting Caspari

es in Hygroph

MEAN (μ)14.4 43.2 1584 28,8 144 1008 1224 259.2

section of lea

he mesophchloropl

y different s

The dimensirophila od

grophila odor

MEAN(28.857.6

115.2100.8

omic structliniana (wa

aquatic piums for m

ntive roots site arrange

root preseal parenchyre 14). Trbent hair; walls and

ma). The rmis, is wian strips.

hila

af

hyll, lasts size

ions dora

ra

(μ)

ture ater

lant many

and d). ents yma The the

few last

well

In fassepwitThelignTheBac9.In epi(FiThecutcan

Figure 13

Figure 14. Ba

central cycicles, resp

parated by th cellulosice pith is nificated wae dimensiocopa coroli

cross-sectidermis, cgure 15). e unistratiticle. The cnals by diffe

3. Bacopa car

acopa carolini(origin

ylinder, thepectively fomedullary

c, thin wallsformed by

alls. ons for miniana roots

tion, the cortex an

fied epiderortex is occerent size (a

roliniana (orig

iana: root cronal)

ere are foour woodenrays forme

s. y cells wi

measured s, are show

stem prend central

ermis is ccupied withaerenchyma

ginal)

oss section

ur liberiann fascicles,ed by cells

ith slightly

tissues, inwn in Table

esents thel cylinder

covered byh aeriferousa) separated

n , s

y

n e

e r

y s d

445

through a cellulosic, developed.by many xon two con

Tabl

NR. 1 2 3

Figur

The pith isThe dimeBacopa ca

Table 10

NR. 1 2 3 4

In cross-seof B. carocuticle; thethin wallepidermis

single layethin walls.

. The centrxylem and ncentric circ

le 9. Tissue diBacopa ca

TISSRizhod

CortCentral c

re 15. Bacopa section

s formed by nsions for roliniana st

. Tissue dimecaroli

TISSUE Cuticle

EpidermisCortex

Central cylin

ection, the moliniana leae upper epled cells;

containin

er of cells. T. The endoral cylinder

phloem vecles.

imensions mearoliniana roo

UE ermis tex cylinder

caroliniana: n (original)

parenchimameasured

tem are sho

nsions measuiniana stalk

s

nder

morpho-anataves presentidermis for

mesophylng differen

The cells hdermis is wis represen

essels arran

easured in ots

MEAN72

288144

stem cross

atous cells. tissues fr

wn Table 1

red in Bacopa

MEAN (μ)14.4 57.6 1728 864

tomic structts: a very t

rmed by larl; the lownt size c

have well nted nged

(μ)

from 0.

a

)

ture thin rger wer

cells

(sm(Fi

Fi

TheundcelspaepichlThefasThecor

NR

1234

ResandmoodoReschecom

T

B

maller than gure 16).

igure 16. Baco

e mesodifferentiatels lacking

aces are idermis theloroplasts. e ribs hacicles (wooe measuremroliniana ar

Table 11. Tis

R.

UppLow

M

sults regardd sodium

orsus-ranae,ora, Bacopasults regaemical idemposition ar

Table 12. Potas

SamplesHydrocharmorsus-ran

Anubias barHygrophila oBacopa caroli

those of

opa carolinian(origin

ophyll ed, formed

intercellureduced.

ere are lay

ave poor ody-adaxial ments for lere indicated

ssue dimensioncaroliniana

TISSUE

per epidermis wer epidermis Mesophyll

Midrib

ding determin aquatic Anubias

a carolinianrding sodntifying inre shown in

ssium and sod

studied aqua

s K+

ris nae

11

rteri 8odora 9iniana

4

the upper

na: cross sectnal)

is homby severa

ular spacesBeneath

yer of cel

developed and liberian

eaf’s tissuesin Table 11

ns measured ia leaves

M

mination ofc plant: H

barteri, Hna dium and n the stun Table 12.

dium determinatic plants

+, ppm N112.97

839.08 919.17

461.18

epidermis)

ion of a leaf

mogeneous,al layers ofs or thesethe upperlls rich in

collateraln-abaxial).s in Bacopa1.

in Bacopa

MEAN (μ)

28.8 28.8 288

187.2

f potassiumHydrocharisHygrophila

potassiumdied plant

nation in the

Na+, ppm 639.40

747.17 779.52

638.82

)

, f e r n

l

a

m s a

m t

446

CONCLUSIONS Although the specialist literature presents aquatic plants having a well developed aerenchyma and reduced mechanical and conducting elements, the submerged plant species Anubias barteri, Hygrophila odora and Bacopa caroliniana show important differences regarding these morpho-anatomic structures. Aerenchyma’s absence both in root, petiole and leaves (Anubias barteri) is correlated with developed conducting elements and sclerenchyma’s presence. The aeriferous tissues recorded in Bacopa caroliniana are reduced, correlated with numerous conducting elements. Hygrophila odora presents a well developed aerenchyma in organ’s structures; the mechanical and conducting elements are reduced, although the xylem vessels are numerous in stem’s structure.

Potassium and sodium identification in the studied plant species (Hydrocharis morsus-ranae, Anubias barteri, Hygrophila odora, Bacopa caroliniana) represent a first step in trying as thorough knowledge of aquatic plants to establish their possible uses. REFERENCES Andrei M., 2003. Microtehnic botanic . Editura

Niculescu SRL, Bucure ti. O’Neil C.R., 2007. European Frog-Bit (Hydrocharis

morsus-ranae) – Floating Invader of Great Lakes Basin Waters. Available online: http://www.seagrant.sunysb.edu/ais/pdfs/Frog-bitFactsheet.pdf

NYSG Invasive Species Factsheet Series: 07-1 ***http://www.liveaquaria.com ***http://naturalaquariums.com/ ***http://www.aquascaping.ro/ ***http://www.flowgrow.de/db/aquaticplants

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