Nodal anatomical study of certain members of the Rutaceae

Keywords: Rutaceae, Node, Nodal evolution.

ABSTRACT: The vascular organization of the node in 12 genera has been investigated. The leaves are unifoliate in Atalantia, Citrus and Paramignya, 3-5 foliate in Aegle, Luvunga, Toddalia and Glycosmis, decompounds in Ruta and imparipinnately compound in other taxa. These are alternate or opposite and exstipulate. The foliar nodes are trilacunar, three-trace in the majority of the plants. It is unilacunar in Atalantia racemosa, Citrus jambhiri, C. maxima and Glycosmis pentaphylla. The results are discussed with respect to the evolutionary conception of node.

177-181 | JRPS | 2013 | Vol 2 | No 1

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Journal of Research in

Plant Sciences An International Scientific

Research Journal

Authors:

Snehal P. Salunke,

Sarala C. Tadavi and

Vijay V. Bhadane.

Institution:

Centre for Post-Graduate

Studies and Research in

Botany, Pratap College,

Amalner - 425 401 [M.S.],

India.

Corresponding author:

Snehal P. Salunke.

Email:

snehal2106@ymail.com

Fax No.:

+91 (02587) 223103

Web Address: http://www.plantsciences.info documents/PS0053.pdf.

Dates: Received: 04 Feb 2013 Accepted: 09 Feb 2013 Published: 05 Mar 2013

Article Citation: Snehal P. Salunke, Sarala C. Tadavi and Vijay V. Bhadane Nodal anatomical study of certain members of the Rutaceae. Journal of Research in Plant Sciences (2013) 2(1): 177-181

An International Scientific Research Journal

Original Research

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INTRODUCTION

The Rutaceae family includes about 160 genera

and 1,900 species that are widely distributed in tropical

and temperate regions around the world, but they are

especially abundant in Australia and South Africa

(Groppo et al., 2008; Cronquist, 1988). While studying

the nodal organization in the angiosperms, Sinnott

(1914) have reported the trilacunar and unilacunar nodal

structure in Rutaceae. Hayward and Long (1942) have

also made observations on variations in the cotyledonary

nodes in Valencia orange. Since the nodal vasculature in

the family has received little attention, it warrants a

detailed study. Consequently the present study were

undertaken to study the nodal organization of

16 species distributed in 12 genera.

MATERIAL AND METHODS

The plant materials of Atalantia monophylla DC,

Toddalia asiatica Lamk. and Glycosmis mauritiana

(Lam.) Tanaka were collected from Lalbagh Botanical

Garden, Bangalore, Citrus jambhiri Lush and

Citrus maxima Merr. were obtained from Parbhani where

as Luvunga eleutherandra Dalz., Clausena dentata

(Willd) Roem and Fagara budrunga Roxb. were

collected from Ratnagiri. Glycosmis pentaphylla (Retz)

DC. was collected from Kalakadu, Tamilnadu.

Paramignya monophylla Wight was collected from

Kegadi forest Nandore while Atalantia racemosa Wight.

Ex. Hook was collected from Gandhinagar, Matheran.

Ruta graveolens L. and Aegle marmelos (L.) Corr. were

obtained from the Pal forest. The young twigs of

Murraya koenigii (L.) Spreng., Murraya paniculata Jack.

and Limonia acidissima L. were locally collected from

the botanical garden of Pratap College, Amalner. The

plant materials fixed in F.A.A. were preserved in 70%

alcohol. Free hand serial sections of the young nodal

regions as well as microtome sections were prepared

following usual method of dehydration, clearing and

embedding in paraffin wax. These were stained either in

safranin-light green combination or crystal violet and

erythrosine.

Observations

The leaves are alternate or opposite, simple or

palmately or pinnately compound, or sometimes heath

like or reduced to spines; stipules are absent. In all the

species examined, the internodal region shows a

complete vascular cylinder. In the nodal region, variable

numbers of leaf traces diverge from the main vascular

cylinder leaving behind prominent gaps.

Trilacunar three-trace node

In Atalantia monophylla , Clausena ,

Glycosmis mauritiana, Limonia, Luvunga, Paramignya,

Toddalia and Ruta (Figures 1-4), the median trace

emerges out first and the two lateral traces diverge out at

the higher level, whereas all the three traces are given out

simultaneously from the main stele in Aegle, Fagara and

Murraya (Figures 5-8).

The median bundle is broad in Limonia, Luvunga

and Ruta and more prominent arc-like in Aegle, Atalantia

monophylla, Clausena, Fagara, Glycosmis mauritiana,

Murraya, Paramignya and Toddalia wherein it breaks up

into 6, 12 or more traces. The lateral bundles divide, may

not divide during their upward course and extend along

with the daughter strands of median, into the rachis. The

three leaf traces - a median and two laterals enter into the

petiole without a division in Limonia acidissima.

Unilacunar one-trace node

This type of node has been observed in

Atalantia racemosa, Citrus jambhiri, C. maxima and

Glycosmis pentaphylla. A prominent arc shaped solitary

vascular trace diverges out leaving a gap in axial

vascular cylinder. It divides in their upward course with

6-9 daughter strands before entering in to the leaf

(Figures 9-15). The node is unilacunar one-trace.

DISCUSSION

A study of the nodal organisation of 16 species

distributed in 12 genera of this family revealed two nodal

Salunke et al.,2013

178 Journal of Research in Plant Sciences (2013) 2(1): 177-181

types: I. Trilacunar three-traced and II. Unilacunar

one-traced. The most common nodal condition is

trilacunar three-traced, it has been observed in 12 out of

16 species investigated. The unilacunar one-traced

condition is exhibited by Atalantia racemosa,

Citrus jambhiri, C. maxima and Glycosmis pentaphylla.

Generally, the median trace emerges prior to the laterals.

It is interesting to note that the median trace and lateral

Salunke et al.,2013

Journal of Research in Plant Sciences (2013) 2(1): 177-181 179

Explanation of Figures:

Figures 1-15 Transections showing structure of foliar node

Figures 1-4. Clausena dentata; Figures 5-8. Aegle marmelos; Figures 9-12. Atalantia racemosa;

Figures 13-15. Glycosmis pentaphylla.

Abbreviations used: MT- Median trace; LT- Lateral trace

traces emerge simultaneously in Murraya, Fagara and

Aegle. The median bundle is broad or more prominent,

arc-like in the majority of the plants and shows a number

of divisions in its upward course. These variations in the

division of the medians and laterals may be looked upon

from the points of view of mechanical strength and size

of leaf.

However, in Limonia acidissima the three leaf

traces-one median and two laterals-extend into the

petiole without a division (cf. Metcalfe and Chalk, 1950).

While reviewing the nodal structure in

angiosperms, Sinnott (1914) writes that the Rutaceae

possess a trilacunar and unilacunar structure. Unilacunar

condition was recorded by Hayward and Long (1942),

while investigating cotyledonary nodes in Citrus

[Valencia orange]. The present study indicates that the

trilacunar-three trace node occurs in majority of the taxa

studied, while the unilacunar structure is noted only in

three genera.

Sinnott (1914) has emphasized the significance

of the leaf trace and leaf gap in the systematics.

Conflicting views have been expressed by various

workers regarding the evolutionary conception of

vegetative node in angiosperms, suggesting both

reduction and/or amplification of vascular traces during

the course of specialization (see Sinnott, 1914; Ozenda,

1949; Marsden and Bailey, 1955; Meeuse, 1966;

Dickson, 1969; Stebbins, 1974). Later, Takhtajan (1969,

1980) postulated tri-or multilacunar type of nodal

structure with double trace in median gap as the most

primitive one, which has given rise to all the nodal types

known presently.

The present study demonstrates that the

trilacunar three-trace node occur in all the taxa except

Atalantia racemosa, Citrus jambhiri, C. maxima and

Glycosmis pentaphylla. Obviously, trilacunar three-

traced condition is considered to be basic for this group

and it is believed that the unilacunar one traced condition

is derived by approximation and coalescence of laterals

with the median, followed by the obliteration of their

gaps. Such a tendency has been observed in some

members of group and a reduction series has been traced.

Thus the present observations lend support to the view of

Sinnott (1914) and Dickson (1969).

ACKNOWLEDGEMENT

The authors are thankful to the Principal, Pratap

College, Amalner for encouragement and providing the

laboratory facilities during the course of investigation.

REFERENCES

Cronquist A. 1988. The evolution and classification of

flowering plants, 2nd edn. The new York Botanical

Garden. New York.

Dickson WC. 1969. Comparative morphological studies

in Dilleniaceae IV Anatomy of node and vascularization

of leaf. J. Arnold Arbor Havri. Univ., 50: 384 - 410.

Groppo M, Pirani JR, Salatino MLF and Blanco SR.

2008. Phylogeny of Rutaceae based on two noncoding

regions from cpDNA. Am. J. Bot., 95: 985 - 1005.

Hayward HE and Long EM. 1942. The Anatomy of

the Seedling and Roots of the Valencia Orange’

Technical Bulletin 786: 1 - 31.

Marsden MPF and Bailey IW. 1955. A fourth type of

nodal anatomy in dicots Illustrated by Clerodendron

trichotomum Thunb. J. Arnold Arbor. Havr. Univ., 36:

36 - 150.

Meeuse ADJ. 1966. Fundamentals of Phytomorphology.

The Ronald Press Co New York.

Metcalfe CR and Chalk L. 1950. Anatomy of the

Dicotyledons: Vol. I, Clarendon Press, Oxford.

Ozenda P. 1949. Recherches sur les dicotyledones

apocarpiques. Publ Lab l’ Ecole Normal Supesieura Ser

Biol Fase II Paris.

Salunke et al.,2013

180 Journal of Research in Plant Sciences (2013) 2(1): 177-181

Sinnott EW. 1914. Investigations on the phylogeny of

the angiosperms I The anatomy of the node as an aid in

the classification of the angiosperms. Amer. J. Bot., 1:

303 - 322.

Sinnott EW and Bailey IW. 1914. Investigations on the

phylogeny of the angiosperms 3: Nodal anatomy and the

morphology of the stipules. Amer. J. Bot., 1: 144 - 459.

Stebbins GL. 1974. Flowering Plants Evolution above

the species level. Edward Arnold Ltd. London.

Takhtajan AL. 1969. Flowering Plants Origin and

Dispersal. (Translated from Russian by C Jeffrey) Oliver

and Boyd Edinburgh.

Takhtajan AL. 1980. Outline of the classification of

flowering plants (Magnoliophyta). Bot. Rev., 46: 225-

359.

Salunke et al.,2013

Journal of Research in Plant Sciences (2013) 2(1): 177-181 181

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