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University of Sulaimani

School of Science

Department of biology

A Comparative study of Leaf Surface Appendages and stomatal

distribution of Alcea kurdica --------------------------------------------------------------------------------------------------------------------------------

A project submitted to the Department of Biology, School of Science, University of Sulaimani in

partial fulfillment of the requirements for the degree of B. Sc. in Biology

Abu Bakr Sidiq Sergeti & Yousuf Abdul Qadir

Supervised by Heyder Usman Fetah, M.Sc in Botany

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Abstract: stomata numbers on upper and lower leaf surface were studied in Alcea kurdica of three

different localities (Sulaimani, Dukan and khurmall).also epidermal appendages (trichomes) were studied

in the same sample on leaf, petiole and stem.it was observed that both stomata and trichomes were more

abundant on the lower leaf surface than the upper ones. Dissecting and compound light microscopes and

also used ordinary camera.

Introduction Order Malvales (mallows) includes only a large

family (Malvaceae) of herbs or shrubs with stellate

hairs, more than (90) genera and (1600) species

found mostly in the tropics and temperate places of

all continents. Some of them are native to Iraq.

Malva (the common mallow, used as food in rural

dishes), Gossypium (cotton), Abolmoschus (okra),

and some ornamentals are members.( Erkan 2012)

The genus named Alcea (mallow, hollyhock) by

the ancient Greek botanist Dioscorides, has more

than (50) species, mainly in South West & Central

Asia, only (five) of them are found in Iraq and

Kurdistan as wild plants and also may be useful for

gardening.

Alcea kurdica is a perennial herb about 30-80 cm

tall, with few or several simple or branched stems.

Branches are rather long ascending in the lower half,

and densely tomentose (hairy), or more rarely

glabrous (naked, no hairs). Trichomes (hairs) are

stellate (star-shaped), sometimes with long rigid

branches (Townsend 1980).

Leaves are very variable in form; cordate (heart-

shaped), orbicular, (circular) with a wide basal

sinus. They have 5-7 broad, shallow, obtuse

(without tip) lobes, or are digitately (finger-like)

divided 3/4 of the way to the petiole with 5-7

oblong or obovate-oblong lobes up to about 3-3.5

times as long as broad. Margins are crenate-serrate.

Upper leaves are frequently more deeply devided.

Leaf indumentum (hairs) densly softly stellate-

tomontose, more rarely rather sparsely stellate

hairy. Petioles of lower leaves are 7-18 cm long, but

upper leaves have gradually shorter stalks. Stipules

are caducous (quickly falling), 5-7 mm long, deeply

bifid (branched) with one or both lobes occasionally

toothed.

Flowers are deep violet-pink to rose-pink, white

or white with a yellow center. Inflorescence is an

elongating raceme, on short (0.5-3cm), ± densly

tomentose peduncles (stalks). Bracteoles maybe 6-

8, from 1/3 to 2/3 as long as the calyx. Calyx is 1.6-

2 cm. long, the sepals are lanceolate-oblong, usually

very distinctly striate (ribbed), stellate-tomentose.

Petals are 4.25-4.75 cm long, broadly cuneate

(triangular) – obcordate (inversed heart-shaped),

with apexes emarginate (lowered tips).

Fruits are about 2 cm in diameter; carpels

yellowish-brown, 5-9 mm in diameter, deeply

sulcate (grooved) dorsaly. Each dorsal margin is

broadly winged. Seed is reniform (kidney-like), 3-5

mm long, with the persistent bases of mostly

deciduous hairs. (Essau 1974).

This plant mostly grows in mountain slopes, in

denuded oak forests, on limestone, igneous and

metamorphic rocks, sometimes in fields and

vineyards in the mountain and on the upper plains.

It prefers altitudes of (150 – 1500) m, and may be

found at (35 -1900) m. Its flowering and fruiting are

in May – July or Aug.

The plant is common in the lower forest zone, and

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occasional in the upper forest zone of Iraq,

(mountains of Kurdistan). Some common places to

be found in are:- Ahmad awa (Atarat 2009), Sinjar,

Zakho, Gare Dagh (Duhok), Amadiya, Sersink,

Zawita, Atrush, Shaqlawa, Bradost, Halgurd, Rayat,

Haji Umran, Qandil, Dokan, Qarahanjir, Derbendi

Bazian, Sulaimani, Kani Spi, Kirkuk, Qara Tepe,

Kifri, Jabal Hamrin, Baghdad, Mosul, etc.

It is also present in some other countries like Crete

(Greece), Cyprus, Syria, Lebanon, Palastine,

Turkey, Iran (Muhammad Karami 2001), and

Afghanistan. (Townsend 1980).

The stomata (sing. Stoma, in Greek means mouth)

are apertures in the epidermis, each bounded by two

guard cells which by changing their shapes control

the size of the stomatal opening, regulate the flow

of gases between the leaf and its environment and

control the amount of water passing through a leaf.

Plants typically close their stomata at daytime to

avoid too much water loss. The aperture leads to a

space (the substomatal chamber), which is

continuous with other intercellular spaces in the

mesophyll. (6)

The stomata are most common on green aerial

parts of plants, particularly the leaves, not found in

chlorophyll-less parasitic plants, nor in roots of any

plants. They occur on some submerged aquatic

plants, and on variously colored petals of the

folwers, sometimes nonfunctional, and also on

stamens and gynoecia. (5)

In green leaves stomata may be on both surfaces

(amphistomatic leaves) or on one only, but

commonly the lower surface has more. This plant,

Alcea kurdica shows this condition.

Guard cells may occur at same level as the

adjacent epidermal cells, or they may protrude

above or be sunken below the surface of the

epidermis. In some plants stomata are restricted to

the epidermis that lines depressions in the leaf, the

stomatal crypts.

The guard cells are generally crescent-shaped with

blunt ends (kidney-shaped) and often have ledges

(shelves) of wall material on the upper and lower

sides. In sectional views such ledges appear like

horns. sometimes a ledge occurs only on the upper

side, or non is present. (Essau 1974).

Microbial entry into host tissue is a critical first

step in causing infection in animals and plants. It

has been assumed formerly that microscopic surface

openings, such as stomata, serve as passive ports of

bacterial entry during infection. Surprisingly, it is

found recently that stomatal closure is a part of

plant innate immune response to restrict bacterial

invasion.(Melotto 2006)

Trichomes (Greek for hairs) are epidermal

appendages of diverse forms, structures, and

functions. They may occur on all parts of the plant,

either they persist throughout the life of an organ, or

they are ephemeral (shortly falling). Some

persisting hairs remain alive; others become devoid

of protoplasts and are retained in dry state. The

epidermal trichomes usually develop early in

relation to the growth of the organ.

Trichomes are morphologically different, one type

is the common hair. In structure they are unicellular

or multicellular, branched or unbranched, uniseriate

or multiseriate, and glandular or nonglandular.

Some trichomes are branched in dendroid (tree-like)

manner; others have branches oriented largely in

one plane (stellate hair). Commonly a multicellular

hair can be divided into a foot, which is embedded

in the epidermis, and a body projecting above the

surface. Cells surrounding the foot are sometimes

morphologically distinct from other epidermal cells.

Another common type of trichome is the scale, also

called peltate hair. It consists of a discoid plate of

cells, often born on a stalk or attached directly to

the foot. The trichome cell walls are commonly of

cellulose and are covered with cuticle, they may be

lignified, or impregnated with silica or calcium

carbonate. The trichomes of Alcea kurdica leaves

belong to the branched hairs (stellate)

(Essau 1974). Trichomes play major roles such helping increase

the rate of water absorption, reducing the rate of

water loss due to evaporation in order to keep the

leaf surface cool, and providing a defence against

insects, since the "hairiness" of the leaf impedes

insect infestation. This is mostly what happens but

maybe some insects prefer it? Glandular or

secretory hairs provide a chemical defense against

potential herbivores.

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Materials & Method:

Ten plant samples of A. kurdica from each three

localities; Sulaimani University campus (the old

campus), Dukan district, and Khurmal district,

were taken randomly. Leaves of different sizes,

ages and positions on the plants, from different

plants (in size, age, and location in the habitat)

were studied for stomata and trichomes on both

sides. Specimens were brought to laboratory fresh

or kept cool in the fridge. Preparations were done

by hand striping-off the epidermal tissue with

simple scalpels. Only water was used in mounting

on glass slides, and both dissecting and compound

microscopes were utilised to observation.

Photographs were taken by ordinary cameras of

suitable resolution.

Results and Discussion

Table (1): Average number of stomata in lower and upper surfaces of Alcea kurdica

leaves in three different locations.

Locality Lower leaf surface stomatal

average (of 10 samples)

Upper leaf surface stomatal

average (of 10 samples)

Sulaimani 20 9

Dukan 16 11

Khurmal 19 10

Figure (1): Average number of stomata in the lower and upper leaf-surfaces of Alcea

kurdica in three different localities.

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Figure(2) :Lower leaf-surface trichome.

Figure (3): Upper leaf-surface Trichome.

.

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Figure (4): Trichomes, lateral views. 10 X.

Figure (5): Trichomes on petiole 10X.

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Figure (6): Trichomes, light Microscope 10 X

Figure (7): Stomata on upper leaf surface of sample in Zanko campus. 40x

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Figure (8): Stomata on lower leaf surface of sample in Zanko campus. 40x

Figure (9): Stomata on lower leaf surface of sample in Zanko campus. 40x

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Figure (11) :Stomata on upper leaf surface of sample in Khurmal 40X .

Figure (10): Stomata on lower leaf surface of sample in Zanko camp, 100x

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Figure (12) :Stomata on lower leaf surface of sample in Khurmal 40X .

Figure (13) :Stomata on upper leaf surface of sample in Dukan 40X .

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Figure (14): Inflorescence of sample plants.

Figure (15): Flower of sample plant.

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Figure (16): Leaf of sample plant.

Figure (17): Sample plant habit.

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Table (1) gives average number of ten samples for each three localities, we can observe that

in all the samples lower leaf surface have more stomata than the upper ones (Shaheen

2010). The difference is near to be 2:1 there are no significant difference between samples

of the three localities. The same difference has been observed between trichomes, numbers

of both leaf surfaces but according to figure (4) the trichomes are stellate branched and

multicellular with articulate septa, same trichomes are crowded in the petiole surfaces and

also on the stem in figure (5).Stomata and trichomes are shown in the figures by

Dissecting microscope and both high and low power of compound microscope. And

according to this observation we have not seen any subsidiary cells, because all the cells

surrounding the guard cells are alike figure (10)

Conclusion:

After much observation, comparison and according to references this plant is one of the

components of the dry habitat flora having characteristic xerophytic features such as

abundant trichomes, robust habit, stomatal concentration mostly in the lower leaf

epidermis.

References:

1. Essau, K. (1974). Plant anatomy. Wiley Eastern, NewDelhi, 2nd

ed. pp. 158- 170.

2. Townsend, C.C. & E. Guest. (1980). Flora of Iraq. V.4. Iraqi ministry of agriculture &Kew

Royal Botanical Gardens. pp. 252-254.

3. Melotto M., William Underwood, Jessica Koczan, Kinya Nomura,and Sheng Yang He.

(2006). Plant Stomata Function in Innate Immunity against Bacterial Invasion. Cell 126.

p.269.

4. Ararat, K., N. Abdul Hassan and S. Abdul Rahman. (2009), Key Biodiversity Survey of

Kurdistan, Northern Iraq, Edited by A. Bachmann, p. 55.

5. Erkan M. Uzunhisarcikli and Mecit Vural.(2012). The taxonomic revision of Alcea and

Althaea (Malvaceae) in Turkey.p.614.

6. Shaheen, N., M.A. Khan, G. Yasmin, M.Q. Hayat, S. Munsif and K. Ahmad, 2010. Foliar

epidermal anatomy and pollen morphology of the genera Alcea and Althaea (malvaceae)

from Pakistan. Int. J. Agric. Biol., vol.12.p.329–334.

7. M. Karami, M. E. Kasmani and A. A. Alamesh. Plants of Hashilan Wetland, Kermanshan,

Iran.(2001). J. Sci. I. R. Iran. Vol. 12, No.3. p.206.

8. http://www.gwannon.com/species/Alcea-kurdica

9. http://www.eoearth.org/article/Stomata?topic=49510.

10. http://www.marietta.edu/~spilatrs/biol103/photolab/stomata.html

11. http://evolution.berkeley.edu/evolibrary/article/mcelwain_03