Pollen Morphology in Some Members of Liliaceae.

M N Shiva Kameshwari / International Journal of Engineering Science and Technology (IJEST)

Pollen Morphology in Some Members of Liliaceae. M N Shiva Kameshwari Department of Botany Bangalore University Jnana Bharathi Campus Bangalore – 560 056

ABSTRACT Pollen of 11 species from 5 genera of the tribe Scilleae, Asphodeleae and Dracaeneae of Liliaceae were examined by light microscope. Detailed pollen morphological characteristics are given for all genera on the basis of the results presented here together with data from the literature. The genera are homogeneous in possessing of single longitudinal aperture (monosulcate) with reticulate Psilate smooth exine, finer differences do exist in the reticulation of the exine between species and populations as seen in U. indica and S. indica. The aperture seen on one side of the pollen grain in tribe Scilleae and in centre of the grain in Asphodeleae and aperture shows wide opening in tribe Dracaeneae. Keywords:

Liliaceae, Urginea, Chlorophytum, Scilla, Drimiopsis Sansevieria..

Introduction The species of Liliaceae under the present study are restricted to tropical regions of India, Africa and Mediterranean region. It comes under the tribe scilleae (urginea, Scilla, Drimiopsis). Asphodeleae (chlorophytum) Draceaneae (Sansevieria). Data on the pollen morphology of the family Liliaceae under the light microscope, (Lm) are given by Zaklinskaya (1953) Huang (1972) Nakamura (1980) Kuprianova (1983) and Ryabkova (1987). A comparative study of the pollen morphology employing electron microscopy has been made by kosenko (1999). The pollen morphology of Nomocharis, Lillium was investigated under LM, SEM and TEM to elucidate the systematics and phylogeny of the genera by Liang and Zhang (1985). In the present study 3 populations of U. indica, 2 populations Scilla indica, Drimiopsis kirkii, 3 species of Chlorophytum, C. elatum, C.heynei and C. laxum and 2 species of Sansevieria i..e, S. zeylanica and S. roxburghiana have been taken to study the pollen morphology. This contribution aims to elucidate the variation between species and the positions of the tribe scilleae, asphodeleae and dracaeneae, with the family liliaceae. The palynological data is an addition parameter taken to delimit the taxa along with other parameters. Materials and Methods Extensive collections were made from various localities, collection of plant materials posed several problems because, most of the taxa appear or flower only during rainy season and remain over ground for a comparatively short duration. All the taxa were brought alive and grown in the departmental garden under uniform environmental conditions.

ISSN : 0975-5462

Vol. 3 No. 5 May 2011

3825


For the study of sporoderm structure of pollen “Acetolysis method of ‘Erdtmann (1943 and 1952) was followed. The pollen terminology follows mainly that of Agashe (2006). Acetoylsed pollen were mounted in glycerine jelly and sealed in paraffin wax. The exine ornamentation and aperture types were examined and photomicrographs of acetolysed pollen were taken using panchromatic 36 mm film, with a leitz microscope using oil immersion optics. Observations The characteristic features of pollen morphology are given in table – 1. Urginea indica – Population (1): Pollen grains monosulcate, boat shaped, ellipitical in distal view. Sulcus long, reaching both the ends of the grains. Exine surface having characteristic micro reticulation 28 µm long and 18 µm wide (Fig 1.a). Urginea indica – Population (2): Pollen grains monosulcate, elongate or almost boat shaped, sulcus lies along the whole length of the grain 34 µm long and 22 µm wide. Exine surface shows macro reticulation while the middle portion of the grain shows micro reticulation (Fig 1. b). Urginea indica – Population (3): Grains are monosulcate, oblate colpus runs along the whole length of the grain. 24 µm long and 17 µm wide. Exine smooth (Fig 1. c). Scilla indica – Population (1): Pollen grains monosulcate and oblate 10 µm long and 7 µm wide. Sulcus runs along whole length of the grain. Exine is psilate (Fig 1. d). Scilla indica – Population (2): Pollen grains monosulcate, elongate 9 µm long and 8µm wide with tapering ends. Sulcus runs along the whole length of the grain. Exine is smooth (Fig 1. e). Drimiospis kirkii: Pollen grains monosulcate and boat shaped 2 µm long and 15 µm wide. Exine shows micro reticulation, sulcus runs along the entire length of the grains (Fig. 1. f) Chlorophytum elatum: Pollen grains monosulcate, ellipsoidal or oblong, elongate 25 µm long and 17 µ m wide. Sulcus runs in the centre of the grains and along the length of the grain. The furrow closing at the ends and wide in the middle often slightly flattened proximally. Exine surface is granular (Fig 2. a). Chlorophytum heynei: Pollen grains are monosulcate 12 µm Takahashi, M. long and 7 µm wide, oblong or ellipsoidal with blunt ends, the sulcus closed and runs along whole length of the grain. Exine surface is granular (Fig 2. b and c). Chlorophytum laxum: Pollen grains monosulcate, 14 µm long and 10 µm wide. Ellipsoidal and deeply channeled sulcus long and runs along the entire length of the grain showing markedly broader ends (Fig 2. d). Sansevieria zeylanica: Pollen grains monosulcate, 37 µm long and 10 µm wide. The grains are oblong elongate, the sulcus runs along the whole length of the grain broader in the middle of tapers towards the ends of the grain. Exine shows faintly reticulate ornamentation (Fig 2. c). Sansevieria roxburghiana: Pollen grains monosulcate, 35 µm long and 15 µm wide, oblong, elongate with sulcus running along the whole length of the grain (slightly visible) Exine shows smooth surface (Fig 2. f). Discussion In the present study on pollen has revealed that in all the species examined, pollen grains are monosulcate oblong with a single colpae extending from one end to the other. But a careful analysis has revealed as is noted in Urginea and Scilla of scilleae even at the population level there are finer differences

ISSN : 0975-5462

Vol. 3 No. 5 May 2011

3826


especially with regard to the size of the grains and the quality of reticulation in exine. Large, boat shaped ellipsoidal monosulcate pollen grains with reticulate exine morphology are the most common type of pollen found in liliaceae Takahashi (1982), Robertson (1966). In all the taxa included in the study there appears to be the size difference of the grains from genus to genus and from species to species. The quality of the reticulation in the exine is also distinct from species to species. Exine varies from reticulate smooth, granular to psilate. Therefore, even at the microscopic level we can find difference among the taxa examined. Studies on other Liliaceae members such as Gloriosa by Ravi Kumar and Nair (1986) and Erythronium by Takahashi (1987) have revealed similar differences at the specific level. Hence, pollen studies undoubtedly are very helpful in correlating relationships. In all the taxa the reticulation of the exine is a general feature but within this general pattern of ornamentation, there are finer differences in the size of reticulation. It is this character that binds them together and separates them apart at the specific and population levels. Several types of exine ornamentation and all main types of Muri are encountered in most heterogenous genus Fritillaria of Liliaceae reported by Kosenko (1999). The presence of a single colpae in the grain is a primitive feature and it is seen in gymnosperms. From this basic aperture the polycolpate and porate grains could be easily derived. Therefore, it is logical to presume the derivation of a large number of monocotyledons family from the liliaceae. Pollen morphological data support the division of the family into 3 tribes, namely scilleae, asphodeleae and dracaeneae. Finally to conclude the 3 tribes i.e., Scilleae, Asphodeleae and Dracaeneae differ in both external morphology and sporoderm structure. The basic palynomorphological characters for the tribe scilleae are the occurrence, of colpae to one side of the pollen grain. In Asphodeleae the colpae runs long the middle of the grain. In Dracacneae colpae runs one either side of the grain showing wide aperture. The palynological, data presented here, obtained from both our own investigations and from the literature confirms that, on the basis of pollen structure. References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13]

Agashe, S.N. (2006) Palynology and its application. Oxford and IBH Publishing Co. Pvt. Ltd., New Delhi. Erdtman, G. (1943) An introduction to pollen analysis, Chronica Bot., Waltham M.A. Erdtman, G. (1952) Pollen morphology and plant taxonomy. Vol.1 Angiosperms Almquist and Wiskell Stockholm. Huang, T.C. (1972) Pollen Flora of Taiwan – Natal. Taiwan University. Taipei. Kosenko, V.N. (1999) Contributions to the pollen morphology and taxonomy of the Liliaceae. Grana. 38: 20 – 30. Kuprianova, L.A. (1983). Erythronium, Tulipa, Lillium, In : Spores of Pteridophytes and pollen of gymnosperms and monocotyledons of the flora of the European Russia 134: 139 – 141, 147 – 149, Nauka, Leningrad (In Russian). Liang, S.Y., Zhang, W.X. (1985) Pollen morphology of the genus Nomocharis and its delimitation with Lillium. Acta phytotax, sin 23: 405 – 417. Nakamura, J. (1980) Diagnostic characters of pollen grains of Japan – Spec. Publ. Osaka, Mus. Nat. Hist 121, 13: 1 – 90 (In Japanese). Ravi Kumar, C., Nair, P.K.K. (1986). Inhertiance of exine ornamentation and pollen shape in the inter specific tetraploid hybrids of Gloriosa. Can. J. Bot. 64: 3134 – 3140. Robertson, K.R. (1966). The genus Erythronium (Liliaceae) in Kansas. Ann. Missouri Bot. Gar. 53: 197 – 204. Ryabkova, L.S. (1987) Palynographs of the flora Tadz SSR. Cupressaceae Portulacaceae Nauka, Leningrad. Takahashi, M. (1982) Pollen morphology in North American Species of Trillium Amer. J. Bot. 69: 1185 – 1195. Takahashi, M. (1987) Pollen morphology in the Genus Erythronium (Liliaceae) and its systematic implications. Amer. J. Bot. 1254 – 1262. Zaklinskaya, E.D. (1950). Liliaceae. In pollen analysis (ed. I.M. Pokrovskaya) 301 – 302. Gosgeolitizdat, Moscow (In Russian).

Acknowledgement I would like to thank Dr. L. Rajanna, Department of Botany, Bangalore University, Bangalore, for his constructive suggestions and to Bangalore University for providing facilities.

ISSN : 0975-5462

Vol. 3 No. 5 May 2011

3827


Table – 1: Characteristics features of the pollen of the Liliaceae species investigated

Species

Pollen size in µm

Aperture type

Exine surface

Urginea indica Population (1)

28 x 18 µm

Monosulcate

Micro reticulate


34 x 22 µm

Monosulcate

Macro reticulate


24 x 17 µm

Monosulcate

Smooth

Scilla indica Population (1)

20 x 12 µm

Monosulcate

Psilate

Scilla indica Population (2)

9 x 8 µm

Monosulcate

Smooth

Drimiopsis kirkii

25 x 15 µm

Monosulcate

Micro reticulate

Chlorophytum elatum

25 x 17 µm

Monosulcate

Granular

Chlorophytum heynei

12 x 7 µm

Monosulcate

Granular

Chlorophytum laxum

14 x 10 µm

Monosulcate

Smooth

Sansevieria zeylanica

37 x 10 µm

Monosulcate

Faintly reticulate

Sansevieria roxburghiana

35 x 15 µm

Monosulcate

Smooth

ISSN : 0975-5462

Vol. 3 No. 5 May 2011

3828


Fig 1. a - f:

Fig 1. a – f: a. b. c. d. e. f.

ISSN : 0975-5462

Pollen Morphology Urginea indica Population (1) Pollen grains in Distal view Urginea indica Population (2) Pollen grains in Equatorial view Urginea indica Population (3) Pollen grains in Proximal view Scilla indica Population (1) Pollen grains in Distal view Scilla indica Population (2) Pollen grains in Proximal view Drimiopsis kirkii Pollen grains in Distal view

Vol. 3 No. 5 May 2011

3829


Fig 2: a – f.

Fig 2. a – f: a. b& c. d. e. f.

ISSN : 0975-5462

Pollen Morphology Chlorphytum elatum Pollen grains in Equatorial view Chlorphytum heynei Pollen grains in Equatorial view Chlorphytum laxum Pollen grains in Equatorial view Sansevieria zeylanica Pollen grains in Equatorial view Sansevieria roxburghiana Pollen grains in Equatorial view

Vol. 3 No. 5 May 2011

3830