A Biosystematical Investigation on Muscari species in Iran
Ali Asghar Maassoumi
The present study tends to investigate
the anatomy and palynology of Muscari species in Iran. To conduct
the comparative study of anatomy characters, sections from root, stem
and leaf were prepared using microtom and differential staining. Among
the organs, mesophyll structure of the leaf displayed a variety among
the subgenera. For the palynology study, too, a comparative investigation
on the species showed some differences in size of sexine areas and grooves
between them were among the subgenera.
Muscari Mill. (Miller, 1754), from Liliaceae,
Lilioideae subfamily and Scilleae tribe (Engler, 1887) has a pan-Mediterranean
origin having numerous variety of species, it is expanded from Mediterranean
to Europe, North Africa and to West Asia (Boissier, 1854; Post, 1935;
Parsa, 1950; Davis and Stuart, 1966; Garbari and Greuter, 1970; Davis
and Stuart, 1980; Pignatti, 1982; Speta, 1982; Davis, 1984; Townsend and
Guest, 1985; Assadi, 1986; Rechinger, 1990). Muscari has 50 species
around the world, about ten of which are found in Iran. Iranian species
belong to three subgenera: Leopoldia, Botryanthus, Pseudomuscari.
The purpose of present biosystematical study is to investigate
the relationship between the inner and outer structural changes. This
respect we collected fresh plants from their localities and reviewed some
dry samples from TARI and IRAN herbariums. In terms of comparative anatomic
studies on Muscari, there hasn`t been anything reported, except
for the presence of contractile root in M. parviflorum (Fahn, 1990).
Then we prepared some cross sections of different organs like root, stem
and leaf. We also did stem maceration. There were found some differences
in the form of leaf mesophyll tissue among the subgenera. In the palynological
study, the comparison were made among the pollen grains of Muscari.
In this part of study, pollen grains were extracted and acetolised, to
study the size, form (shape) and ornamentation of the pollen through SEM
and LM. Significant differences among the subgenera were observed concerning
depth, width of muri and shape of luminas.
MATERIALS AND METHODS
As for the anatomic study, fresh samples were collected
from the north, east, west and center of Iran to be studied along with
dry samples from TARI and IRAN herbariums February until June 2003, 2004
(Table 1). Having been fixed in FAA, then they were
dehydrated with ethanol and later, some slices were prepared with microtom.
The section-12 micron thick- were then stained with Safranin and Fast-green
(Johnson, 1940; Chamberlain, 1990). For the stem maceration, this organ
was placed in Jeffery solution for 6 h to soften. In the palynological
study, the pollen were extracted from the anther and dehydrated by Glacial
acetic acid, then, acetolised and finally studied by SEM and LM (Erdtman,
1952; Moore et al., 1991). Pollen terminology was adapted from
Punt (Punt et al., 1994).
Anatomic results: The results from the anatomic
studies demonstrated the root with the following tissues:
||Some parenchymatous layers with small cells under the
||Some parenchymatous layers with large cells and idioblasts containing
raphid and helical thickening vessel (Fig. 1)
In the stem, we found the following tissues:
||Some (several) parenchymatous layers with small cells under the
|| Species, their locality and voucher specimen
||Longitudinal section of root, (a) parenchyma with small
cell, (b) helical thickening vessel and (c) parenchyma with large
cell (x 940)
||Longitudinal section of stem, (a) parenchyma with small
cell, (b) sclerenchyma, (c) helical thickening tracheid and (d) parenchyma
with large cell (x940)
||Some sclerenchymatous layers with small cells
||Some parenchymatous layers with large cells, idioblast and helical
thickening tracheids (Fig. 2)
The results from stem maceration confirmed the presence
of bipolar sclereids which had created some branches in the intercellular
The results from the anatomic study of the leaf showed
two kind of mesophyll: the upper, the medial and the lower, which the
upper and the lower ones are
||Cross section of leaf of M. comosum from subgen
Leopoldia with palisade mesophyll (x416)
||Cross section of leaf of M. tenuiflorum with
large intercellular in medial mesophyll (x416)
identical in that both are made of two cell layers. However,
the form of leaf mesophyll cells are different among the subgenera. The
form of both upper and lower mesophylls tissue in M. comosum (L.)
Mill (Fig. 3), M. caucasicum (Griseb.) Baker,
M. longipes Boiss from subgen. Leopoldia are palisade, with
little intercellular space.
In M. tenuiflorum from subgen. Leopoldia,
both mesophylls tissue are palisade, but there is no intercellular space.
Medial mesophyll tissue is wider and has some small cells with huge intercellular
spaces (Fig. 4).
In M. neglectum Guss., M. armeniacum Baker
var. szovitzianum Stuart. from subgen. Botryanthus, the
shapes of upper and lower mesophyll tissues range from elliptical to spherical
and are totally narrower than the medial mesophyll. Also in M. neglectum,
medial mesophyll has huge intercellular spaces (Fig. 5).
Both the upper and lower mesophyll tissue in M. commutatum Guss., M. microstomum Davis and Stuart (Fig.6) from subgen. Bothyanthus, are spherical to elliptical. Medial
mesophyll in M. microstomum, haven`t intercellular spaces. In M.
pseudomuscari from subgen. Pseudomuscari, both upper and lower
mesophyll tissues show elliptical to spherical and the thickness of the
medial mesophyll is the same as the two others (Fig. 7).
||Cross section of leaf of M. neglectum from subgen.
Botryanthus with elliptical-spherical mesophyll. Arrow shows intercellular
||Cross section of leaf of M. microstomum with
elliptical mesophyll (x416)
||Cross section of leaf of M. pseudomuscari from
subgen. Pseudomuscari with spherical-elliptical mesophyll (x416)
Palynology results: The pollen grains are elliptical,
monosulcate, bilateral symmetric, distal-polar, semi- tectate, without
annulus, negative reticulate. The colpus is very long, curving around
the ends of the grain so that it is almost divided into two lobes like
the halves of a bivalve mollusc shell (Woudenhouse, 1935; Zavada, 1983;
Fumess and Rudall, 1999; Harley and Zavada, 2000). Negative sexine means
a pattern of ornamentation in which sexine areas are separated by narrow,
||Scanning electromicrograph of pollen. of M. comosum
with small sexine areas, narrow and shallow grooves (SEM x250)
||Scanning electromicrograph of pollen of M. tenuiflorum
with large sexine areas, deep and wide grooves (SEM x250)
||Scanning electromicrograph of pollen of M. commutatum
with large sexine areas, deep and wide grooves (SEM x250)
arranged grooves. The pollen of M. comosum (Fig.
8) and M. caucasicum from subgen. Leopoldia has small
sexine area, smooth surface with narrow and shallow grooves.
|| The ratio of P/E (polar axis length/equatorial axis
||Scanning of electromicrograph of pollen of M. neglectum
with soft surface, small sexine areas, narrow and shallow grooves
||Scanning electromicrograph of pollen. M. pseudomuscari
with large sexine areas, deep and wide grooves (SEM x250)
The pollen of M. tenuiflorum (Fig.
9) and M. longipes from the same subgenus (Leopoldia)
have large sexine area with deep and wide grooves. In M. commutatum
(Fig. 10), M. microstomum and M. inconstrictum
from subgen. Botryanthus, the pollen have large sexine area with
wide and deep grooves, too. In contrast to M. neglectum (Fig.
11), M. armeniacum var. szovitziamum which go to the
same subgenus, have a pollen with smooth surface, small sexine areas with
very narrow and shallow grooves. In M. pseudomuscari from subgen.
Pseudomuscari, the pollen has relatively large sexine are with
wide and deep grooves (Fig. 12). Furthermore, P/E ratio
(polaraxis length/equatorial axis length) were calculated. The maximum
ratio was related to M. pseudomuscari with 1.58 while the minimum
was 1.23 for M. longipes (Table 2).
As the results from the anatomic studies about Muscari
suggest, we can state the anatomic structure of the roots and stems
in all subgenera under the investigation, were similar while significant
differences in the shape of the leaf mesophyll tissues were observed.
For example, the upper and lower mesophyll tissues in subgen. Leopoldia
were palisade, while in subgen. Botryanthus, they were elliptical
to spherical and in subgen. Pseudomuscari, spherical to elliptical.
The thickness of medial mesophyll was either the same as the other or
wider than them in all subgenera. Sometimes some intercellular spaces
could be observed in medial mesophyll tissues. As for the taxonomic position,
the subgenera fall in the following order: Leopoldia, Botryanthus,
Pseudomuscari (Stuart, 1965). Regarding the shape of the leaf
mesophyll tissues, some changes were also observed: e.g., in subgen. Leopoldia
there was palisade which changed to elliptical in subgen. Botryanthus
and to spherical in subgen. Pseudomuscari. Thus, there must
be a relationship between the taxonomic position of subgenera and the
changes of leaf mesophyll tissues form.
Studying of the pollen of subgen. Leopoldia, two
types of pollen ornamentations were observed:
||Pollen with small sexine areas, smooth surface, narrow and shallow
||Pollen which had large sexine areas, wide and deep grooves
In subgen. Botryanthus-as the above subgenus-we
also had both types, but in subgen. Pseudomuscari, the pollen had
large sexine areas with wide and deep grooves.
In subgen. Leopoldia, two types of pollen ornamentation
were observed. Besides, in the species which are morphologically identical
in pairs, the ornamentation were also the same. In subgen. Botryanthus,
too, we had two types of ornamentation. One of them was specific to
M. neglectum and the other one which is similar to that of subgen.
Pseudomuscari. Other three species e.g., M. microstomum,
M. inconstrictum and M. commutatum had the same pollen ornamentation.
This could lie in the fact that the three species are morphologically
similar to M. pseudomuscari. In that they have almost no clear
contraction at the corolla throat.
In conclusion, we can say that the similarity of their
ornamentation, to some extant, related to their morphological similarity.
However, one can not attribute such similarity to recognize taxonomic
situation of species.
Assadi, M., 1988.
Plants of Arasbaran protected area, Nw. Iran. Part II. Research institute of forests and rangelands. Iranian J. Bot., 4: 54-54.
Boissier, E., 1854.
Fl. Or. Nov. Ser. 1, 13: 36
Chamberlain, C.J., 1990.
Methods in Plant Histology. 5th Edn., Arihant Publishers, Jaipu, India, pp: 112-132, 144-145
Davis, P.H. and D.C. Stuart, 1966.
Three new species of Muscari
. RHS Lily Year Book, pp: 123-125.
Davis, P.H. and D.C. Stuart, 1980. Muscari
mill. Tutin, T.G. et al. (Eds.). Fl. Europea. Cambridge, 5: 46-49.
Davis, P.H., 1984.
Flora of Turkey. 1st Edn., Edinburgh University Press, pp:264-274
Engler, A., 1887.
Liliaceae engler and prantle. Die naturlichen pflanzenfamilien. Leipzig, 2: 10-91.
Erdtman, G., 1952.
Pollen Morphology and Plant Taxonomy Angiosperms. Chronica Botanica Co., Waltham, Stockholm, Sweden
Fahn, A., 1990.
Plant Anatomy. 4th Edn., Pergamon Press, New York, ISBN: 0-08-037491-3
Fumess, C.A. and P.J. Rudall, 1999.
In aperture pollen in monocotyledons. Int. J. Plant Sci., 160: 395-414.
Garbari, F. and W. Greuter, 1970.
On the taxonomy and typification of Muscari
miller (Liliaceae) and allied genera and on the typification of generic names. Taxon, 19: 329-335.Direct Link |
Harley, N.M. and M.S. Zavada, 2000.
Pollen of Monocotyledons: Selecting Characters of Cladistic Analysis. In: Monocots: System and Evolation, CSIRO, Melbourne, pp: 194-211
Johansen, D.A., 1940.
Plant Microtechnique: Jeffrey's Method. MacGraw Hill Book Co., New York, USA., pp: 104
Miller, P., 1754.
The gardeners dictionary. 4th Edn. London, pp: 927.
Moore, P.D., J.A. Webb and M.E. Collinson, 1991.
Pollen Analysis. 2nd Edn., Black Well Scientific Publication Oxford, London, ISBN: 086542-8956, pp: 39-82
Parsa, A., 1950.
Flore de Iran. 5: 332- 352.
Pignatti, S., 1982.
Flora d Italia vo: terzo. pp: 374-379.
Post, G., 1935.
Flora of Syria. Palaestina Sinai, 4: 647-652.
Punt, W., S. Blackmore, S. Nilsson and A. Le Thomas, 1994.
Glossary of pollen and spore Terminology. Utrecht. LPP Foundation (LPP contributions Series. No. 1).
Rechinger, K.H., 1990. Muscari
. In: Flora Iranica (Liliaceae 2), Rechinger, K.H., K. Browicz, K. Persson and P.Wendelbo (Eds.). Academic druck. Verlagsanstatt, Graz. Austria, pp: 140-143
Speta, F., 1982.
[On the delimitation and subdivision of the genus Muscari and on its relationship with other representatives of the Hyacinthaceae]. Bot. Jahrb., 103: 247-291.Direct Link |
Stuart, D., 1965. Muscari
and allied genera. A Lily Group Discussion. The Lily Year Book, pp: 125-138.
Townsend, C. and G. Guest, 1985.
Flora of Iraq. 8: 128.
Woudenhouse, R.P., 1935.
Pollen grain, their structure and signification in science and medicine. 1st Edn. McGraw Hill Book Company Inc., pp: 153-183.
Zavada, M.S., 1983.
Comparative morphology of monocot pollen and evolutionary trends of apertures and wall structures. Bot. Rev., 49: 331-379.CrossRef | Direct Link |