STUDIES ON MORPHOLOGICAL, ANATOMICAL AND EPIDERMAL LAYERS IN WILD SPECIES OF CYMBOPOGON MARTINII (ROXB.) FROM SOUTH INDIA

* K. J. Thara Saraswathi 1 , Hemalatha J 2 , Vijayalakshmi K 2 , Gourab Ray 2 and Shivakameshwari. M. N 3 . 1. Professor, Department of Microbiology and Biotechnology, Jnana Bharathi Campus, Bangalore University, Bengaluru – 560056. 2. Research scholar, Department of Microbiology and Biotechnology, Jnana Bharathi Campus, Bangalore University, Bengaluru – 560056. 3. Assistant Professor, Dept. of Botany, Bangalore University, Bengaluru-560056. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History


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percentage of geraniol content (Bor 1953). The "motia" variety yield Palmarosa oil and "sofia" variety yield Ginger grass oil, commercially utilized for perfumery and medicinal purposes (Maffei 2002). India was the major producer of oil along with Guatemala, China, Mexico and Bangladesh. The oil finds extensive application in perfumery, cosmetic, flavor and aroma therapy. It is also an effective insect repellent used to store grains, antihelminthic to nematodes, antifungal and exhibit mosquito repellent properties (Olorunnisola et al., 2014). The Palmarosa oil possesses characteristic aroma resembling rose scent and thus added to soaps and cosmetics (Rao et al., 2005). The plant is source of high grade geraniol (75-95%) used as starting material for number of synthetic aromatic chemicals like geranyl esters (Soenarko 1977;Jagadishchandra 1975).
During the present investigation an attempt has been made to collect the wild "ecotypes" of C.martinii from different locations of South India and details on plant morphology, leaf anatomy and epidermal layers were investigated.

Morphological Characters:
The morphological characters like length and thickness of Culm, length and breadth of leaf, texture and color of the leaf, angle of the leaf with Culm, length of ligule, length of leaf sheath, length of inflorescence, nature of branching, length of spatheole, shape of the bisexual spikelet were studied from the flowering culms.
Leaf Anatomy: Leaf anatomy was studied by taking transverse section of lamina. The fresh leaf material was treated with FAA (90 ml of 70% ethanol + 5 ml of glacial acetic acid + 5 ml of formaldehyde solution) for 48 hours and washed in water. The mid portion of leaf blade was selected and transferred to 10% hydrofluoric acid for 24 hours, washed in running water for 2 hours and transferred to 70% ethanol. The sections of leaf blade were taken, treated with hypochlorite solution for 25 min, washed and preserved in 70% ethanol.
The sections were stained using a mixture of 94 parts of 1% Saffranin in 70% ethanol and 6 parts of Delafield"s Hematoxylin for 30-120 min. The material was washed in 50% ethanol, dehydrated in alcohol series cleared in xylol and mounted in Canada balsam (Metcalfe 1960). For the description of lamina, standard methods were followed (Ellies, 1976).

Epidermal layer:
The technique described by Metcalfe (Metcalfe 1960) was followed to study the details of epidermis. The mid portion of leaf blade was cut (half way between the blade apex and the ligule of leaf) and placed on the slide. The material was first washed in laboratory detergent solution and the tissue above the epidermis to be examined was 336 scraped off using razor blade. The epidermis was washed in water and the adhering cells were carefully removed using soft brush.
(iii) Leaf epidermal characteristics: Short cells in intercostal region solitary, in coastal bands they alternate with silica bodies in long uninterrupted rows; silica bodies dumb-bell shaped, long cells with thin sinuous walls; only micro hairs present, hooks absent, microhairs 40-44 µm long, basal cell 20-22 µm long, inflated, distal cell 20-22 µm long, tapering in to sharp apex; stomata in long rows with high-dome-shaped subsidiary cells; leaf margin almost smooth with very few blunt prickles at tip of leaf (Fig 6c). Flowering: November -December. Specimens collected: Kemmanagundi (Karnataka) Habitat: Rocky hill slopes.

Discussion:
During the study based on distinct morpho-anatomical characters of the plant, eleven types (Type 1 to 11) were recognized in the wild collections of C.martinii from South India. The Type-1 of C. martinii differs anatomically from rest of the Types by possessing a distinct midrib instead of keel, by possessing marked microhairs on the abaxial surface and by conspicuously absence of hooks. The Type-2 showed unique characteristics and differed from other Types in their morphology having gigantic size and besides, anatomically showed the presence of considerably large keel. Type-3 has a characteristic leaf blade which is coarsely scabrid along the margin and possesses hooks and microhairs and narrow keel. Type-4 to Type-9 differs from the rest in possessing lamina that forms a characteristic acute angle with the culms. The said morphological features seem to be characteristics of the C. martinii variety sofia in the species recognized (Gulati et al. 1970).
Many other characters of the variety Sofia such as the ploidy, the size and shape of the sessile spikelet, including the habit and habitat were, however, characteristically found only in Type-5. Hence Type-5 is recognized as similar and synonymous to C. martinii variety sofia (Gulati et al. 1970).
Type-8 and Type-9 resemble each other in habit, in the short stature of plants, and in possessing a lamina of narrow keels, but differ in their leaf angles and trichomes. The leaves of Type-8 form obtuse angle with the culm whereas those of Type-9 form acute angle with culm. Further in Type-8 the hooks were absent from abaxial epidermis whereas hooks in Type-9, Type-6 resembles Type-5 in many respects but differs from it in leaf character forming an obtuse angle with the culm and absence of hooks. Type-7 differs from rest of the Types in having the aerial parts of the plant body suffused with purple color; the leaf margin being smooth and the median bundle not projecting abaxially. These grasses are medium statured and very common in South India, possessing cordate leaves with a narrow keel and median bundle being projecting abaxially, both microhairs and hooks are present. Type-11 differs from others possessing culms with all nodes exposed, narrow short keel and absence of hooks on the abaxial epidermis, the leaf margin being coarse with prickles.
The present studies on the C. martinii of Rusae and the types recognized in each species reveal that there is no drastic variation with regard to the structure and morphology of the spikelets, both within and between the species, indicating the floral homogeneity of the members and the series as whole. However, leaf morphology and its anatomy, in addition to the general morphology of the plants; have yielded valuable information of taxonomic importance.
Controversies have existed for many years among different workers as to the number of varieties to be recognized under C. martinii, the famous "Rosha" grass of commerce. However, the two varieties recognized from earlier are sofia and motia (Stapf 1906) and has been validated recently (Gulati et al. 1970;Mathela et al. 1990).
Collections under the Type-5 are synonymous and equivalent to variety martinii and variety Sofia respectively. The rest of the Types described under C. martinii are very distinct in their morpho-anatomical characters deserve varietal 347 status and will have to be formally described under the respective species in further morphological studies of the wild species.
The leaf anatomy in the wild C. martinii revealed the taxonomical differences existing between the Types (Type 1-11). The leaf blades of approximately same age group were used for the present study. The mesophyll showing radiating chlorenchyma, bundle sheath single with large chloroplasts; starch grains in bundle sheath cells (as confirmed by iodine test) indicated Kranz Syndrome leaf anatomy in all the Types. The present investigations were noted to be characteristic and found to be consistent in each of the recognized Types.