Lambert Academic Publication(LAP),GERMANY

Contents
S.No. Particulars Page
No.
1 Air Pollution Impact on Flowers 01-24
1.1 Introduction
1.2 Selection and Description of Test Species
1.2.1.1 Caesalpinia pulcherrima Swtz. (Swartz)
1.2.1.2 Cassia fistula Linn.
1.2.1.3 Cassia siamea Lamk. Syn.
1.2.1.4 Delonix regia Hook (Bojer ex Hook)
1.2.1.5 Peltophorum inerme Roxb.
1.2.2 Flowering Time
1.2.2.1 Air Pollutants
1.2.2.2 Sources of Air Pollution
1.2.2.3 Sources of Air Pollutants
1.2.2.4 Effects of Air Pollution
1.2.2.6 Need of Air Quality Monitoring
1.2.3 Soil Pollution
1.2.3.1 Types of Soil Pollution
1.2.3.2 Causes of Soil Pollution
1.2.3.3 Pollution Due to Urbanisation
1.2.3.4 Effects of Soil Pollution
1.2.3.5 Long Term Effects of Soil Pollution
1.2.3.6 Control of soil pollution
1.2.4 Noise Pollution
1.2.4.1 Sources of noise
1.2.4.2 Measures of noise
1.2.4.3 Effects of noise pollution
1.2.4.4 Causes and Effects of Noise Pollution
1.3 Results
1.3.2 Floral Morphology
1.3.3 Flower Colour
1.3.4 Floral Biomass
1.3.5 Pollen Germination
1.3.6 Pollen Size
1.3.7 Pollen Tube Length
1.3.8 Pollen Viability
1.4 Discussion
1.4.1 Time of Flowering
1.4.2 Morphology of Flowers
1.4.3 Flower Colour
1.4.5 Pollen Characters

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2 Air Pollution Impact on Fruits 25-36
2.1 Introduction
2.2 Experimental
2.2.1 Colour of Pods
2.2.2 Size of Pods
2.2.3 Weight of Pods
2.2.4 Seed Count
2.2.5 Seed Viability
2.3 Results
2.3.2 Size of Pods
2.3.4 Seed Count
2.4 Discussion
3 Air Pollution Impact on Seed Quality and Germination 37-47
3.1 Introduction
3.2 Experimental
3.2.1 Seed Colour
3.2.2 Seed Weight
3.2.3 Seed Density
3.2.4 Seed Soundness
3.2.5 Seed Germination
3.3 Results
3.3.1 Seed Colour
3.3.2 Seed Weight
3.3.3 Seed Density
3.3.4 Seed Soundness
3.3.5 Seed Germination
3.4 Discussion
Acknowledgement 48
References 49-57

ii

Air Pollution Impact on Reproductive Behaviour of Few
Tropical Trees

Dr. Kishore Pawar, Dr. O.P.Joshi and Dr. Hema Swami
Department of Environment
Holkar Science College, Indore – 452 017- India

Air Pollution Impact on Flowers

1.1 Introduction
To survive and do well, flowering plants have to reproduce themselves
successfully. It is beneficial to the species if reproduction is carried out by
sexual means, because this introduces greater variability in to the resulting
offspring‟s, which in turns allow more opportunity for the species to evolve
with its environment. The most colourful and spectacular aspects of plant
growth are associated with development of flowers and fruits. Flower formation
signifies a transition from vegetative to the reproductive phase of development.
The shoot meristem is induced to develop sepals, petals, stamens and carpels
instead of leaves. This transition can only occur at a particular time in the life of
plants, which within certain limits, is determined genetically. Infect
reproductive growth is certainly a complex process and physiologists have
recognized a number of partial processes, which have been intensively studied.

Ordinarily in thinking of reproductive growth, flower formation and fruit
development come to mind. These events are obvious to the naked eye.
However, each of these processes is the culmination of a number of other
events, many of which are microscopic or submicroscopic. The reproductive
growth is complex and encompasses a variety of anatomical, morphological,
physiological and bio-chemical processes.

After the plant attains the ripe to flower condition further progress towards
flower initiation depends on the environment, both temperature and light are
involved. Infect reproductive growth is certainly a complex processes, which
have been intensively studied.

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In this process two stages must be distinguished from each other, the induction
of flowering and the differentiation of flowers and inflorescence. Everyone is
familiar with flowers. Botanically flower is a modified shoot consisting of
protective leaves, i.e. sepals and decorative coloured petals. These represent the
parts of the flowers that is most familiar and indeed, generally thought of „the
flower‟. Sepals and petals protect essential parts of the flowers, the male and
female organs. The female part of the flower usually forms the central portion
and it consists of one or more carpels, each of which contains one or more egg
or ovules, mounted by a style and stigma. The stigma is the receptive surface on
which pollen grains can land and grow, while the style is simply its stalk.

The male parts are usually found in a ring around the central female parts, and
they consist of pollen bearing stamens. Flowers may be produced singly or in-
group known as inflorescence. The purpose of these aggregations normally
seems to be an aid in attracting potential pollinators. During postembryonic
development in higher plants, the shoot apex undergoes three discernible phases
- juvenile vegetative, adult and reproductive. The transition from the juvenile to
adult phase is usually gradual and involves subtle changes in shoot morphology
and physiology (Poethig 1990). The intermediate developmental patterns are
common during the transition from vegetative to reproductive stages.
Infect, differentiation of the reproductive organ is preceded by formation of
sepals and petals. That has a combination of vegetative and non-vegetative
characters (Shrivastava and Iqbal 1994).

For flowering the size of the shoot is more important than its age. In several
species, shoot undergoes flowering on reaching a certain stage of development
(Robinson and Warening 1969). The regulatory mechanism ensures that the
plant does not flower until it has attained the requisite size. This holds true even
in plants requiring a specific day length or chilling.

1.2. Selection and Description of Test Species
The five tree species selected for the present study belongs to family- Fabaceae.
These trees are of good ornamental value. They are planted on roadside, in
gardens and even in home gardens. They give a good colour effect; attract birds,
bees and butterflies, which pollinate them. They are important component of

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urban ecosystem and presently facing threat due to harmful and toxic effect of
urban air pollutants. A brief taxonomic description of these plants is presented
below:

1.2.1.1 Caesalpinia pulcherrima Swtz. (Swartz)

A glabrous shrub or a small tree unarmed or with a few weak prickles,
cultivated in gardens, generally throughout India (Plate 1.1). It is commonly
known as Shankhasur, Gultora, Chhoti-gulmohar and Krishna chura.

Leaves- 15-30 cm. Long, alternate, pinnae 6-8, leaflets, 8-12 in pairs, sessile
and oblong.
Flowers- Scarlet yellow or red in elongate auxiliary and terminal racemes.
Total five petals sub-equal, transversely oblong.
Stamens- 10, free, filament long, petaloid.
Pods- Oblong and flat, glabrescent, narrower and thinner than those of any of
the genus.
Seeds- 8-10 obviate – oblong and glabrous.
Flowering- Nearly throughout the year.

Plate 1.1: Caesalpinia pulcherrima in flowering at Low Pollution Area

1.2.1.2 Cassia fistula Linn.
A very handsome tree 20-30 feet high, trunk straight, bark smooth and pale gray
when young, rough and dark-brown, when old, branches spreading, slender
(Plate 1.2). This is a well-recognized avenue tree, occasionally found in
deciduous forest also, commonly known as Amaltas.

3

Leaves- 9-16 inches long main rachis pubescent, stipules minute, linear oblong,
obtuse, pubescent.

Leaflets- 4-8 pairs, ovate or ovate-oblong, acute, bright green, glabrous and
silvery-pubescent beneath when young, the midrib densely pubescent at the
underside, base cuneate.

Plate 1.2: Cassia fistula with developing pods showing flowers in inset.

Flowers- In racemes 12-20 inches long, pedicels 1½ - 2 ¼ inches long, slender,
pubescent and glabrous.

Sepals- 5, pubescent, oblong.

Petals- 5, sub-equal obovate, shortly clawed, veined.

Stamens- 10, the 3 longest stamens are much curved and bear large, oblong
curved anthers, the 4 median stamens are straight and 3 remaining are very short
and erect staminode, dehiscing longitudinally by pores.

Pods- 2-3 feet long, 1-3/4 inches in diameter, pendulous, cylindrical, nearly
straight, smooth, shining, brown-black, not torulose, indehiscent with numerous
(40-100) horizontal seeds immersed in a dark coloured sweetish pulp, and
completely separated by transverse partition.

Flowering- April-June.

Fruiting- Persisting throughout the year.

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1.2.1.3 Cassia siamea Lamk. Syn.

Evergreen tree of moderate size having nearly smooth, gray bark marked with
slight longitudinally fissures (Plate 1.3). The Cassia siamea is a native of South
India and Burma. It is now grown throughout the India planted on roadside and
in gardens for its shade and showy flowers. Its dark green, glossy leaves are
divided into two rows of narrow, pointed leaflet arranged in opposite pairs on
the slender midrib.

Plate 1.3: Cassia siamea with flowers and fruits at Low Pollution Area.

Leaves- Peripinnate about 12 inches long, leaflets 12 to 20, elliptical-oblong,
mucronate, glabrous.

Flowers- Yellow grow in large, open clusters at the ends of the branches about
1 ¼ inches, each of the flower having five almost equal petals and perfect seven
stamens nearly unequal that produce pollen, the remaining three stamens being
wanting, or small and sterile.

Pods- The flat pods are purplish or brown, when ripe and contain a number of
seeds. When young, they are soft, ribbon-like, minutely velvety, 6 to 9 inches
long.

Flowering– Throughout the year, maximum flush is observed in October.

Fruiting- April and throughout the year.

1.2.1.4 Delonix regia Hook (Bojer ex Hook)
Delonix is a quick growing evergreen tree with slightly rough, grayish, brown
bark, and a rather slender trunk, which usually soon divides into a number of

5

spreading, limb, bearing delicate feathery foliage 7-12 meter tall (Plate 1.4). It is
planted in gardens, roadsides and at public places, as an ornamental shade tree.

Plate 1.4: Delonix regia growing in Low Pollution Area with flowers in inset.

Leaves - 15- 40 cm long, alternate, bipinnate compound, pinnae 8-20 pairs,
leaflet 15-20 pairs.

Flowers- 3 to 4 inches across petal, obviate, clawed, in terminal, simple or
branched racemes, flowers red or orange in colour, the upper petal striped with
yellow or white.

Stamens- 10, exerted, red.

Pods- 30-40 x 3 - 4.5 cm broadly linear, flat woody beaked, dark brown in
colour.

Seeds– Numerous, oblong, glabrous, smooth, white or creamy, mottled.

Flowering- April-July.

Fruiting - December.

1.2.1.5 Peltophorum inerme Roxb.
Peltophorum is evergreen tree, 8-20 meter tall, handsome, dark foliaged
younger parts rusty brown or grayish tomentose, panicles of showy yellow
flowers (Plate 1.5). It is usually planted in gardens and along the roadsides as an
ornamental shade tree.

Leaves –12-30 cm long, alternate, pinnae, 6-13 pairs.

6

Leaflets - 6-17 pairs, oblong, glabrous.

Flowers- Bright yellow, in terminal racemose panicles.

Plate 1.5: Blooming Peltophorum inerme growing in Low Pollution Area

Stamens- 10, free, hairy at base golden-yellow.

Pods- Lanceolate, 5-10 x 1.6 –2.2 cm, oblong, flat, hard, narrowed at both ends,
indehiscent, woody, margin winged, rusty red in colour.

Seeds– Usually 3-5, brown, obovate, oblong, compressed, smooth, flat and
glabrous.

Flowering- April-June.
Fruiting– December- January.


The data of intiating flowering for Caesalpinia pulcherrima, Cassia fistula,
Cassia siamea, Delonix regia and Peltophorum inerme was noted for two
consecutive years 2002 and 2003.


To study the floral morphology flowers were collected in between 9 to 11 AM
from the height of 3 to 5 meters from the ground level. Hundred flowers were

7

collected from each plant species (25 flowers each from four different trees)
from sampling sites in polythene bag sealed with adhesive tape and were
brought to the laboratory. Measurement of length and breadth of sepals, petals,
stamens and carpel were taken with a standard scale.

1.2.4 Flower Colour

The anthocyanin content of flowers, growing in different areas was determined
following Drumm and Mohr (1978). For floral estimation 200 mg of petals were
dipped into 5 cm3 of methanolic HCl (1%) v/v and kept overnight at 5 to 10 C
(Stafford 1966).

After centrifugation, the absorbance of supernatant was measured at 525 nm, in
spectrophotometer. The anthocyanin content was expressed as absorbance per
100 mg fresh weight. Each mean value represent an average of three
independent replicates.


Floral biomass was determined by collecting 100 flowers from each site from
the height of 3 to 5 meters. Sampling was done in the morning hours between 9
to 10 am. Flowers were brought to the laboratory in polythene bags sealed with
adhesive tape. After taking their fresh weight flowers placed in an oven at 80 C
for 24 hours and later on the dry weight was recorded.


Freshly opened flowers were collected during 9 to 10 AM in polythene bags
from Industrial Pollution Area (IPA), Vehicular Pollution Area (VPA) and Low
Pollution Area (LPA) for pollen germination studies. Sucrose and boric acid
solutions of different grades were prepared following Brewbakar and Kwack
(1963). Pollen grains were placed in most suitable concentrations, i.e. (8%
sucrose and 200 g of boric acid) on cavity slides, which were kept in petridish
containing moist filter paper inside to maintain the appropriate relative
humidity. The slides were observed under microscope at every one-hour
interval to record the results. Pollen grains were considered germinated only,

8

when pollen tubes attained a size doubled of the grains. Ten random
microscopic fields (10 x 10 X) in each of the slides were examined to determine
the pollen germination. Pollen tube length and pollen diameter was measured
using an Ocular Micrometer.


Pollen viability was determined by using 1 % TTC [2, 3, 5–Triphenyl-
tetrazolium chloride] following Norton (1966). Pollen grains were incubated in
1 % TTC for 60 minutes at room temperature. The pollen grains were placed in
a drop of this solution on a glass slides, with cover slip and these slides were
kept in petriplates lined with moist filter paper and stored in a dark place. The
numbers of pollen grains, which became reddish in colour, were recorded as
viable.

1.3 Results


A delay in flowering time from 7 to 20 days was observed in all plants species
in both IPA and VPA as compared to LPA. Maximum delayed flowering was
noted in Cassia fistula. However, Caesalpina pulcherrima was found to be
relatively unaffected (Table 1.1).
Table 1.1: Delay in flowering period of tree species growing in different polluted
areas of Indore city in comparison to Low Pollution Area
Industrial Pollution Area Vehicular Pollution Area
TPL* 539.15 g/ m3 TPL 506.81 g/ m3
Name of plant
species Delay in Delay in Delay in Delay in
Flowering Flowering Flowering Flowering
2003 2004 2003 2004
C. fistula 12-15 days 14-16 days 11-14 days 15-20 days
C. siamea 15-20 days 16-18 days 10-12 days 8-10 days
C. pulcherrima 7-10 days 5 -7 days 8-11 days 11-14 days
D. regia 10-12 days 15-18 days 12-18 days 10-12 days
P. inerme 8-10 days 9-11 days 15-18 days 18-21 days
*TPL -Total Pollution Load (SO2 + NOx + SPM)

Flowers collected from polluted sites showed reduction in length and breadth of
sepals and petals. Length of stamens and carpel was also noted reduced (Table

9

1.2 to 1.6 and Fig. 1.1, 1.2 and 1.3). Maximum reduction was found in
Peltophorum inerme, i.e. 26.71 and 59.0 %, 27.48 and 53.30 % in IPA and VPA
respectively in length of sepals and petals. Whereas Caesalpinia pulcherrima
showed minimum reduction, i.e. 3.27 % in sepals and 7.84, 13.27 % both in IPA
and VPA.
Table 1.2: Length and breadth (cm) of different floral parts of Cassia fistula
LPA IPA VPA
Parameters TPL* TPL* % Reduction TPL* % Reduction
308.02 g/ m3 539.15 g/ m3 506.81 g/ m3
Length of 1.22 1.14 1.18
sepals** 1.23 1.11 1.14
1.26 1.10 1.16
Average *** 1.23±0.16 1.11±0.16 9.75 % 1.16±0.16 5.69 %
Breadth of 0.48 0.27 0.32
sepals** 0.49 0.30 0.36
0.47 0.32 0.38
Average*** 0.48±0.08 0.29±0.20 39.58 % 0.35±0.21 27.0 %
Length of 2.83 1.18 1.87
petals** 2.86 1.14 1.74
2.84 2.20 1.69
Average*** 2.84±0.14 2.17±1.16 23.59 % 1.76±0.20 28.87 %
Breadth of 1.08 0.52 0.92
petals** 1.49 0.60 0.69
1.08 0.94 0.84
Average*** 1.21±0.60 0.68±0.57 43.25 % 0.81±0.41 32.25 %
**Length 2.15 1.11 1.98
of stamens 1.87 1.12 0.99
2.08 1.12 1.24
Average*** 2.03±0.46 0.90±0.53 44.82 % 1.40±0.74 30.87 %
Length of 1.97 0.96 1.43
Carpel** 1.70 0.92 1.29
1.71 0.87 1.20
Average*** 1.79±0.35 0.91±0.55 49.16 % 1.30±0.02 27.37 %
*TPL – Total Pollution Load, ** - Average of 100 flowers; *** - Average of 300 flowers
LPA - Low Pollution Area, IPA- Industrial Pollution Area; VPA- Vehicular Pollution Area
Table 1.3 : Length and breadth (cm) of different floral parts of Cassia siamea
LPA IPA VPA
Parameters TPL* TPL* % TPL* %
308.02 g/ m3 539.15 g/ m3 Reduction 506.81 g/ m3 Reduction
Length of 1.30 1.10 1.12
sepals** 1.31 0.99 1.11
1.33 0.96 1.18
Average *** 1.31±0.14 1.01±0.20 22.90 % 1.13±0.57 13.74 %
Breadth of 0.68 0.45 0.48
sepals** 0.67 0.46 0.47
0.69 0.47 0.49
Average*** 0.68±0.11 0.46±0.11 32.35 % 0.48±0.11 29.41 %
Length of 2.43 0.97 0.99
petals** 2.40 0.98 1.21
2.41 1.12 1.10
Average*** 2.41±0.14 1.02±2.79 57.67 % 1.10±0.38 54.35 %

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LPA IPA VPA
Parameters TPL* TPL* % TPL* %
308.02 g/ m3 539.15 g/ m3 Reduction 506.81 g/ m3 Reduction
Breadth of 1.20 0.60 0.69
petals** 1.21 0.58 0.61
1.19 0.59 0.59
Average*** 1.20±0.11 0.59±011 50.83 % 0.63±0.08 47.5 %
**Length of 1.48 0.99 0.87
stamens 1.49 0.98 0.90
1.48 0.97 0.90
Average*** 1.48±0.08 0.98±0.11 33.78 % 0.90±0.08 39.18 %
Length of 1.50 1.47 1.48
Carpel** 1.50 1.48 1.49
1.49 1.46 1.48
Average*** 1.50±0.08 1.47±0.11 2.0 % 1.48±0.08 1.33 %

Table 1.4: Length and breadth (cm) of different floral parts of Caesalpinia pulcherrima
LPA IPA VPA
Parameters TPL* TPL* % Reduction TPL* %
308.02 g/ m3 539.15 g/ m3 506.81 g/ m3 Reduction
Length of 1.22 1.18 1.19
sepals** 1.26 1.17 1.18
1.20 1.20 1.17
Average *** 1.22±0.20 1.18±0.16 3.27 % 1.18±0.11 3.27 %
Breadth of 0.58 0.48 0.38
sepals** 0.49 0.40 0.47
0.48 0.46 0.48
Average*** 0.51±0.20 0.47±0.18 7.84 % 0.44±0.29 13.27 %
Length of 2.84 2.81 1.90
petals** 2.85 2.80 1.99
2.82 2.82 2.00
Average*** 2.83±0.16 2.81±0.11 0.70 % 1.96±0.29 30.74 %
Breadth of 0.64 0.59 0.48
petals** 0.59 0.58 0.61
0.62 0.60 0.49
Average*** 0.61±0.21 0.59±0.11 3.27 % 0.52±0.25 14.75 %
**Length 4.6 3.9 4.00
of stamens 4.4 4.1 4.2
4.3 3.8 3.9
Average*** 4.4±0.16 3.9±0.37 11.36 % 4.0±0.37 8.33 %
Length of 4.2 4.0 4.1
Carpel** 4.1 3.7 3.9
3.9 3.5 3.7
Average*** 4.0±0.57 3.7±0.46 7.5 % 3.9±0.51 2.5 %

Table 1.5 : Length and breadth (cm) of different floral parts of Delonix regia
LPA IPA VPA
Length of 2.30 2.00 2.13
sepals** 2.33 1.99 2.00
2.45 1.98 2.18
Average *** 2.36±0.34 1.99±0.11 15.67 % 2.10±0.37 11.01 %
Breadth of 0.88 0.70 0.72
sepals** 0.80 0.71 0.71
0.69 0.69 0.72
Average*** 0.79±0.85 0.70±0.11 11.39 % 0.71±0.11 10.12 %

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LPA IPA VPA
Length of 5.27 4.12 4.25
petals** 5.30 4.11 4.33
5.54 4.28 4.69
Average*** 5.37±0.47 4.17±0.66 22.34 % 4.42±0.59 17.69 %
Breadth of 3.72 3.10 3.41
petals** 3.68 3.18 3.20
3.67 3.04 3.11
Average*** 3.69±0.20 3.10±0.30 15.98 % 3.57±0.21 3.25 %
**Length 3.80 2.52 3.20
of stamens 3.70 3.60 2.99
3.90 2.80 3.40
Average*** 3.80±0.36 2.97±0.77 21.84 % 3.19±0.40 18.42 %
Length of 4.30 4.70 4.40
Carpel** 3.90 2.87 3.80
4.80 3.80 4.40
Average*** 4.30±0.25 3.79±1.00 11.86 % 4.20±0.36 2.32 %

Table 1.6 : Length and breadth (cm) of different floral parts of Peltophorum inerme
LPA IPA VPA
Parameters TPL* TPL* % Reduction TPL* % Reduction
308.02 g/ m3 539.15 g/ m3 506.81 g/ m3
Length of 1.31 0.99 0.98
sepals** 1.32 0.96 0.91
1.30 0.94 0.98
Average *** 1.31±0.11 0.96±0.46 26.71 % 0.95±0.25 27.48 %
Breadth of 0.70 0.37 0.30
sepals** 0.69 0.30 0.36
0.67 0.32 0.25
Average*** 0.68±0.14 0.33±0.20 51.47 % 0.30±0.27 55.88 %
Length of 2.42 1.11 1.12
petals** 2.41 0.99 1.11
2.43 0.96 1.18
Average*** 2.42±0.11 0.99±0.34 59.0 % 1.13±0.23 53.30 %
Breadth of 1.21 0.38 0.42
petals** 1.19 0.45 0.47
1.42 0.46 0.50
Average*** 1.27±0.40 0.43±0.21 66.14 % 0.46±0.24 63.77 %
**Length of 1.40 0.86 0.89
stamens 1.49 0.87 0.87
1.50 0.88 0.96
Average*** 1.46±0.18 0.87±0.11 43.15 % 0.90±0.25 38.35 %
Length of 1.70 0.84 0.85
Carpel** 1.50 0.86 0.79
1.50 0.99 0.95
Average*** 1.56±0.23 0.89±0.34 42.94 % 0.86±0.37 44.87 %

The response of petals to air pollution was also similar to the sepals. The
perusal of tables clearly indicates that there was more reduction in length of
sepals and petals as compared to their width. The size of stamens and carpel
was also affected by pollution stress. Out of five test species maximum
reduction in length of stamens was noted in Cassia fistula, i.e. 44.82 and
30.87% in IPA and VPA respectively followed by Cassia siamea (Table 1.2 and

12

1.3), whereas minimum reduction in stamen size was found in Caesalpinia
pulcherrima, i.e. 11.36 and 8.33 % in IPA and VPA.

Regarding carpel, maximum reduction was found in Cassia fistula, where the
values were 49.16 and 27.37 % in IPA and VPA respectively. However the
minimum reduction in carpel length was observed in Cassia siamea (Table 1.3).
Overall it can be concluded that reduction in size of stamens and carpel was
more significant than sepals and petals. Flowers growing in IPA found to be
more affected than that of roadside plants (Fig. 1.1, 1.2 and 1.3).

Fig 1.1: % reduction in length and breadth of sepals over LPA
60

50

40
% Reduction

30

20 C.fistula
C.siamea
C.pulcherrima
10
D.regia
P.inerme
0
length of sepals breadth of sepals
IPA VPA

Fig 1.2 : % reduction in length and breadth of petals over LPA.
70

60

50
Reduction

40

30
%

C.fistula
20 C.siamea
C.pulcherrima
D.regia
10 P.inerme

0

IPAIPA VPA
VPA
Length of Petals Breadth of Petals Length of Petals Breadth of Petals

Fig 1.3 : % reduction in length of stamens and carpel over LPA
50 C.fistula
C.siamea
45
C.pulcherrima
D.regia
40
P.inerme

35

30
% Reduction

25

20

15

10

5

0
IPALength of stamens
IPA Length of carpel VPA
Length of Stamens Length of Carpels Length of Stamens Length of Carpels

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1.3.3 Flower Colour

The anthocyanins are known to impart colour to the flowers along with
carotenoids. In present study, it is visualized that air pollutants affected the
colour of flowers adversely. In general, an overall reducing trend was observed
in the floral colour in all the five test species in both the polluted sites as
compared to the reference area (Table 1.7 to 1.11). The data clearly indicates
that the flowers developing in vehicular pollution areas were affected more
adversely than the Industrially Polluted Area.

It is inferred that there was an overall increment in pigment content in all five
species with their increasing exposure time. However, when compared with the
pigment content of reference area a reduction was noted. The maximum
reduction in anthocyanin content in third day flower stage was observed in P.
inerme in VPA, which was 27.45% followed by C. fistula (18.46%); while it
was minimum in C. siamea, i.e. only 3.15%.

When compared to differently polluted area the floral pigment to be more
sensitive to vehicular pollution than industrial. This is true for all the five
species. Thus it appears that air around road side is more toxic to flower than
other areas in spite of low pollution load as compared to industrial area.
Table 1.7 : Anthocyanin content (/mg fresh weight) of Cassia fistula
LPA IPA VPA
TPL*308.02 g/ m3 TPL* 539.15 g/ m3 TPL* 506.81 g/ m3
Time Increase Increase over Increase Increase over % Increase Increase over %
exposure (in mg) 0 day (in mg) 0 day Reduction (in mg) 0 day Reduction
0 day 0.93 0.94 0.87
0.94 0.96 0.88
0.96 0.95 0.87
Average 0.95  0.16 0.00 0.95  0.11 0.00 0.00 0.87 0.08 0.00 8.42
1 day 0.96 0.98 0.94
0.95 0.98 0.96
0.97 0.97 0.95
Average 0.96 0.11 0.01 0.98  0.08 0.03 2.08 0.95 0.11 0.08 1.04
2ndday 1.24 1.04 1.06
1.22 1.06 1.06
1.23 1.05 1.09
Average 1.23 0.11 0.27 1.05  0.11 0.10 14.63 1.07 0.08 0.20 13.00
3rd day 1.31 1.20 1.05
1.29 1.21 1.08
1.30 1.20 1.07
Average 1.30  0.11 0.35 1.20 0.08 0.25 7.69 1.06  0.16 0.19 18.46
4th day 1.29 1.09 0.99
1.26 1.11 1.10
1.27 1.10 0.98
Average 1.27  0.14 0.28 1.10  0.11 0.15 13.38 1.05  0.34 0.13 21.25
*TPL -Total Pollution Load, LPA - Low Pollution Area, IPA- Industrial Pollution Area; VPA- Vehicular Pollution Area

14

Table 1.8 : Anthocyanin content (/mg fresh weight) of Cassia siamea
LPA IPA VPA
0 day 0.89 0.74 0.68
0.88 0.75 0.68
0.89 0.74 0.67
Average 0.89  0.08 0.00 0.74 0.08 0.00 16.85 0.67 0.08 0.00 23.59
1 day 0.89 0.94 0.89
0.91 0.93 0.70
0.90 0.95 0.70
Average 0.90 0.11 0.01 0.94  0.11 0.20 4.4 0.70  0.08 0.02 22.22
2ndday 0.89 0.94 0.71
0.90 0.96 0.72
0.90 0.95 0.72
Average 0.90  0.08 0.01 0.95  0.11 0.21 5.55 0.72 0.08 0.04 20.00
3rd day 0.94 0.96 0.98
0.96 0.95 0.98
0.95 0.97 0.97
Average 0.95  0.11 0.06 0.96 0.11 0.22 1.05 0.98 0.08 0.03 3.15
4th day 1.06 1.04 1.07
1.06 1.06 1.09
1.09 1.03 1.08
Average 1.07 0.12 0.12 1.05 0.14 0.3 1.86 1.08 0.11 0.4 0.93

Table 1.9 : Anthocyanin content (/mg fresh weight) of Caesalpinia pulcherrima
LPA IPA VPA
0 day 0.98 0.89 0.88
0.98 0.91 0.89
0.97 0.90 0.89
Average 0.98 0.08 0.00 0.90 0.11 0.00 8.16 0.89 0.08 0.00 9.18
1 day 1.01 0.91 0.98
1.03 0.91 0.97
1.02 0.90 0.98
Average 1.02  0.11 0.04 0.91  0.08 1.00 1.07 0.98 0.08 0.09 3.92
2ndday 1.03 1.03 0.98
1.04 1.02 0.99
1.04 1.01 0.99
Average 1.04 0.08 0.06 1.02 0.11 12.0 1.92 0.99 0.08 0.10 4.80
3rd day 1.06 1.09 0.99
1.06 1.11 0.98
1.07 1.10 0.99
Average 1.07  0.11 0.09 1.10 0.11 20.0 2.80 0.99  0.08 0.10 7.47
4th day 1.28 1.20 1.20
1.27 1.19 1.21
1.22 1.19 1.20
Average 1.25  0.23 0.27 1.19  0.08 29.0 4.8 1.20 0.08 0.31 4.0

Table 1.10 : Anthocyanin content (/mg fresh weight) of Delonix regia
LPA IPA VPA
0 day 1.01 0.89 0.89
0.02 0.90 0.88
0.03 0.90 0.89
Average 0.02 0.11 0.00 0.90 0.08 0.00 10.78 0.89 0.08 0.00 12.74
1 day 1.03 0.89 0.90
1.05 0.91 0.89
1.04 0.91 0.89
Average 1.04 0.08 0.02 0.91 0.08 0.20 12.5 0.90 0.08 0.01 13.46
2ndday 1.20 1.19 0.90
1.22 1.20 1.06
1.21 1.21 1.07
Average 1.21 0.08 0.17 1.20 0.11 0.17 0.82 1.08 0.08 0.18 11.5
3rd day 1.20 1.20 1.01
1.21 1.21 1.02
1.20 1.20 1.02
Average 1.20 0.08 0.16 1.20 0.08 0.16 00 1.02 0.08 0.13 15.0

15

LPA IPA VPA
4th day 1.09 1.00 1.00
1.10 1.01 1.01
1.11 1.00 1.00
Average 1.10 0.08 0.08 1.00 0.08 0.08 9.0 1.00 0.08 0.11 9.0

Table 1.11 : Anthocyanin content (/mg fresh weight) of Peltophorum inerme
LPA IPA VPA
0 day 0.78 0.74 0.67
0.78 0.73 0.68
0.79 0.73 0.68
Average 0.78 0.08 0.00 0.73 0.08 0.00 6.4 0.68 0.08 0.00 12.8
1 day 0.79 0.79 0.69
0.80 0.78 0.70
0.80 0.78 0.70
Average 0.80 0.08 0.02 0.78 0.08 0.05 2.5 0.70 0.08 0.02 12.5
2ndday 0.98 0.98 0.79
0.99 0.97 0.80
0.99 0.98 0.80
Average 0.99 0.21 0.21 0.980.08 0.25 1.0 0.80 0.08 0.10 19.19
3rd day 1.01 0.98 0.73
1.02 0.99 0.74
1.03 0.99 0.75
Average 1.02 0.14 0.24 0.99 0.08 0.26 2.94 0.74 0.11 0.06 27.45
4th day 0.99 0.98 0.74
0.98 0.97 0.76
0.99 0.97 0.75
Average 0.99  0.11 0.21 0.97 0.08 0.24 2.02 0.75 0.11 0.07 24.24

Fresh and dry weights of flowers of different plant species are presented in
Table 1.12 and % reduction is presented in Fig. 1.4. It is evident that maximum
reduction in flower weight has taken place in vehicular area and minimum at
industrial area. Out of five test species, it is observed that flowers of Delonix

Fig 1.4 : % Reduction in fresh and dry weight of flower over LPA.
50

45

40

35

30
C.fistula
% REDUCTION

C.siamea
25 C.pulcherrima
D.regia
P.inerme
20

15

10

5

0
Fresh weight IPA
IPA VPA
Fresh Weight Dry Weight Fresh Weight Dry Weight

16

regia appeared to be more sensitive to air pollution, as regards the biomass, as
there was 35.95 % and 43.77 % reduction in dry weight was noted respectively
in both IPA and VPA. Minimum reduction was noted in Peltophorum inerme
19.40% and 27.53% in both IPA and VPA in dry weight as compared to
unaffected area, i.e. LPA. These results once again proved the toxicity of the air
pollutants (Fig. 1.4).

Table 1.12 : Fresh and Dry weight (g) of 100 flowers
Low Pollution Area Industrial Pollution Area Vehicular Pollution Area
Name of plant TPL*308.02 g/m3 TPL* 539.15 g/m3 TPL* 506.81 g/m3
species Fresh wt. Dry Fresh wt. % Dry wt. % Fresh wt. % Dry wt. %
wt. Red. Red. Red. Red.
C. fistula 60.00 6.75 58.60 5.30 56.98 4.60
65.50 7.36 54.00 12.71 4.88 29.78 54.05 13.93 4.36 38.20
68.00 7.65 56.30 5.09 55.51 4.48
Average 64.50±3.26 7.25 ±0.37 56.30±1.75 5.09±0.52 55.51±1.39 4.48±1.37
C. siamea 32.00 5.30 31.07 4.13 33.34 3.74
35.50 5.87 28.00 15.17 3.72 31.84 28.50 12.53 3.19 40.72
37.50 6.21 30.00 3.98 30.00 3.36
Average 35.00±2.00 5.79±0.81 29.69±1.49 3.94±0.54 30.61±1.90 3.43±0.61
C. pulcherrima 25.00 3.19 24.61 2.62 24.82 2.50
28.50 3.63 28.00 6.59 2.98 22.09 22.00 20.91 2.21 37.56
31.00 3.95 26.30 2.79 20.00 2.01
Average 28.16±2.05 3.59±1.00 26.30±1.50 2.79±.43 22.27±3.79 2.24±0.20
D. regia 200.0 43.72 198.01 29.43 197.82 27.53
215.0 46.99 195.05 5.18 28.99 35.95 175.00 11.68 24.35 43.77
211.0 46.12 196.53 29.21 180.00 25.05
Average 208.66±2.90 45.61±1.35 196.53±1.40 29.21±0.54 184.27±3.51 25.64±1.67
P. inerme 35.00 11.64 33.46 11.11 33.92 10.42
40.50 13.46 30.00 19.32 9.96 19.40 28.00 21.24 8.60 27.20
42.50 14.13 31.73 10.53 31.00 9.52
Average 39.33±2.40 13.07±1.35 31.73±1.51 10.53±0.87 30.97±1.99 9.51±1.10

Air pollution has also been found to affect pollen germination adversely in all
test species (Table 1.13 and Fig. 1.5). The maximum reduction in percent
germination of pollen grains was noted in Cassia siamea i.e. 31.51 in VPA, and
minimum in Cistula fistula 19.15 % in IPA. Whereas maximum reduction was
noted in C. pulcherrima 17.08% and minimum in Cassia siamea 0.97%. Thus
different species respond differently two types of pollution.

Table 1.13 : Pollen germination of studied plants growing in different polluted areas of Indore city
LPA IPA VPA
Name of plant TPL* 308.02 TPL* % Reduction TPL* % Reduction
species g/m3 539.15 g/m3 506.81 g/m3
C. fistula 74.33 2.03 60.09 1.93 19.15 % 63.00  4.66 15.24 %
C. siamea 67.91 2.33 46.51  2.3 31.51 % 67.25 1.99 0.97 %
C. pulcherrima 65.83 1.23 51.58 1.95 21.64 % 54.58 2.1 17.08 %
D. regia 84.04 7.08 63.68 4.33 24.22 % 73.11 7.08 13.00 %
P. inerme 84.98 1.34 62.72 3.46 26.19 % 73.28 5.38 13.76 %

17

1.3.6 Pollen Size

The size of pollen grains was found to be affected by pollution stress. (Table
1.14 and Fig.1.6). Higher percentage reduction was noted in IPA than in
roadside plants. Maximum reduction in pollen size was observed in Delonix
regia, i.e. 48.83 and 42.48 % respectively in IPA and VPA sites. While
minimum reduction was noted in Peltophorum inerme 15.54 and 13.26 %
respectively at IPA and VPA sites. It is evident from data presented in Table
1.6. that in IPA, air was more harmful for the pollens growth and development
than VPA. A size wise reduction was also noted. The greater the size of the
pollen, more was the reduction irrespective of the pollution area. Smaller size
pollens were least affected like P. inerme.

Table 1.14 : Pollen diameter () in plants growing in different polluted areas of Indore city
LPA IPA VPA
Name of plant TPL* 308.02 TPL* % Reduction TPL* % Reduction
species g/m3 539.15 g/m3 506.81 g/m3
C. fistula 53.1± 1.24 43.5 ± 1.25 18.07 % 45.2 ± 1.23 14.87 %
C. siamea 57 ± 1.30 38.1 ± 1.39 33.15 % 38.8 ± 1.28 31.92 %
C. pulcherrima 54 ± 1.20 37.1 ± 1.38 31.29 % 38.7 ± 1.27 28.33 %
D. regia 64.5 ± 1.27 33.0 ± 1.27 48.83 % 37.1 ± 1.38 42.48 %
P. inerme 52.1 ± 1.24 44 ± 1.25 15.54 % 45.0 ± 1.22 13.62 %
Fig. 1.6 : % reduction in Pollen size over control.
60

50

40
% Reduction

C.fistula
C.siamea
30 C.pulcherrima
D.regia
P.inerme
20

10

0
IPA IPA VPA

18

1.3.7 Pollen Tube Length
Pollen tube length was found to be much lower in IPA as compared to VPA. A
general reducing trend in pollen tube length in both polluted sites was recorded.
(Table 1.15 and Fig. 1.7). The maximum reduction in pollen tube length was
noted in Cassia siamea, i.e. 52.98, 46.51 % in IPA and VPA respectively.
Whereas minimum reduction in IPA in Caesalpinia pulcherrima 19.17% and
Delonix regia 16.16% in VPA respectively as compared to unaffected area.
D. regia was least affected by pollution stress.

Table 1.15 : Pollen tube length () of studied plants growing in different polluted areas of Indore city
LPA IPA VPA
Name of Plant TPL* 308.02 TPL* % Reduction TPL* % Reduction
species g/m3 539.15 g/m3 506.81 g/m3
C. fistula 176.1 ± 21.22 137.1 ± 19.08 22.20 % 138.5 ± 19.03 21.35 %
C. siamea 218.0 ± 7.06 102.5 ± 8.23 52.98 % 116.6 ± 19.61 46.51 %
C. pulcherrima 182.5 ± 30.41 147.5 ± 29.18 19.17 % 138.5 ± 15.80 31.67 %
D. regia 177.5 ± 30.76 143.3 ± 12.11 19.26 % 148.0 ± 19.86 16.61 %
P. inerme 182.6 ± 33.58 126.5 ± 22.76 30.72 % 138.5 ± 22.5 24.15 %

Fig 1.7 : % reduction in pollen tube length over LPA.
60

50

40
% Reduction

IPA
30
VPA

20

10

0
C.fistula C.siamea C.pulcherrima D.regia P.inerme


Pollen viability is a very important character to assess reproductive behaviour of
plants. In present study it was noted to be reduced in both the polluted sites
(Table 1.16 and Fig. 1.8). There was more reduction in pollen viability in VPA
as compared to IPA. The maximum reduction in pollen viability was found in
Peltophorum inerme 38.27 % and Caesalpinia pulcherrima, i.e. 38.29% in IPA
and VPA and minimum reduction was recorded in Cassia siamea, i.e. 20.73 %

19

and 17.07 % in both IPA and VPA. Thus it appears that to urban air pollutants
the least affected pollens grains were of Cassia siamea.

Table 1.16 : Percent viable pollens of studied plants growing in different polluted areas of Indore city
Name of Total no. Viable Non- Total no. Viable Non-viable % Red. in Total no. Viable Non-viable % Red. in
plant species of pollens pollens viable of pollens pollens pollens viable of pollens pollens pollens viable
pollens pollens pollens
C. fistula 96 83 13 79 63 16 24.09 69 61 08 26.50
C. siamea 90 82 08 74 65 09 20.73 79 68 11 17.07
C. pulcherrima 98 94 04 76 67 09 28.72 64 58 06 38.29
D. regia 84 73 11 70 55 15 31.50 70 57 13 21.91
P. inerme 88 81 07 60 50 10 38.27 71 61 10 24.69
Fig 1.8 : % reduction in pollen viabilty over LPA.
60

50

C.fistula
C.siamea
C.pulcherrima
40 D.regia
P.inerme
% Reduction

30

20

10

IPA VPA
0
IPA

1.4 Discussion

1.4.1 Time of Flowering

Air pollutants are influencing the plants in various ways. Apart from vegetative
parts, reproductive parts are also showing significant variations under pollution
stress. One of the most prominent features is delayed flowering in plants
growing in polluted habitats. Pawar (1983) and Dubey (1985) have reported this
in Mangferia indica, Delonix regia and Acacia arabica trees growing in
industrially polluted area with predominance of SO2. Recently Chauhan et al.
(2004) has also reported delayed flowering and reduced floral density in Cassia
siamea growing along road side of Agra one of the highly polluted cities of our
country. Thus the present findings are in confirmation with these earlier reports.
Pawar and Dubey (1985) correlate this delay with air pollution stress because
due to many physiological and bio-chemical alterations, less photosynthate is
available for reproductive growth and development.

20

1.4.2 Morphology of Flowers

Higher value of Length and Breadth ratio (L/B) clearly indicated that there was
more reduction in length of sepals and petals as compared to their width.
Generally reduction in length of both floral parts, i.e. sepals and petals results
has been noted maximum.

The reduction in number of flower size and cone development due to the air
pollution specially SO2 has been reported by many workers (Houston and
Dochinger 1977, Beda 1982 and Ernst et al. 1985) Flower size reduction in
calendula due to SO2 exposure has been reported (Singh et al. 1985 and Yunus
et al. 1985).

Joshi and Sikka (2002) have reported reduced fresh and dry weight in flowers of
Cassia fistula, Delonix regia and Peltophorum inerme growing in differently
polluted are of Indore city. Pollution induced changes in floral morphology of
Cassia siamea has been reported recently by Chauhan et al. (2004).

Higher reduction in size of stamens and carpel in comparison to sepals and
petals can be attributed to their more complex physiological and biochemical
requirements. Maximum flower size reduction in C. fistula as compared to other
species is a result of its higher sensitivity to air pollution, which has been
reported earlier on the basis of various morphological and phytochemical
observations by many workers (Pawar 1982, Joshi 1989, Singh and Rao 1983,
Agrawal 1986). Thus it is obvious that C. fistula is a very sensitive plant to
urban air pollution not only regarding its vegetative and biochemical aspects but
reproductive behaviour as well.

1.4.3 Flower Colour

Increment in floral pigment with their age can be attributed to the effect of light.
Exposure of plants to white light increases the anthocyanin content in flowers
resulted in their darkening (Stafford 1965 and Drumm and Mohr 1978). In the
present study also the same pattern was observed. However the higher rates of
reduction in anthocyanin pigment of flowers growing in polluted sites with their
exposure time in comparison to low polluted area can be attributed to the
phytotoxic activity of air pollutants. The decrease in floral colour in polluted

21

areas appears to be enzymatic in nature. Increased activities of glucosidase and
poly-phenolonidase in the plant growing in mixed pollution area (Godzite 1967)
and glycosidase (Bucher 1979) have been reported, which are known to reduce
their pigments (Goodwin 1976). One of the reasons for plant wise variation in
anthocyanin content reduction can be related to the thickness of petals. More
reduction in P. inerme and C. fistula may be due their thin and delicates petals.
Since the bright colour of flowers serve to attract the pollinators and thus ensure
the pollination effectively. Fading of the flowers in such polluted habitats may
also results in less fruiting and seed setting especially in entomophyllous
flowers.


Decrease flower weight in polluted sites is related to reduction in floral size.
Such changes in floral biomass can be either indirect effect of air pollution due
to less allocation of photosynthates (Lechowicz 1987) or a direct effect of toxic
gases on floral parts during their growth and development. There observations
are in confirmation with earlier reports (Joshi and Sikka 2002). Higher
sensitivity of Cassia fistula flower in comparison to rest of the species can be
attributed to its overall sensitivity of plant, and can be accounted to the delicacy
of floral parts, which remained totally exposed to pollutants to right from their
initiation to full bloom in absence of leaves. Minimum alteration in C. siamea
and P. inerme can be account on their resistant nature of their plants. These two
plants have also been reported to have higher value of Air pollution Tolerance
Index (Singh and Rao 1983 and Agrawal 1986).

1.4.5 Pollen Characters

The pollen grains are very sensitive to air pollution and thus have been used for
monitoring of atmospheric pollution (Rosen 1983). The sensitivity of pollens to
SO2 (Karmosky and Stairs 1974 and Varshney and Varshney 1981) and
fluorides (Facteau and Rowe 1977) has been reported as poor germination and
reduced tube growth.

In present study also reduction in pollen grains size, viability, germination and
tube length has been noted in all the plant species studied. These effects are

22

considered to be the influence of various air pollution combinations of IPA and
VPA sites, effect of other pollutants cannot be denied too.

Increased SO2 concentration is reported to reduce pollen germination
significantly (Dubey 1983 and Varshney and Varshney 1981, 1986). Similarly
Krishnayya and Bedi (1986) have reported reduced pollen germination and seed
viability in two species of Cassia growing near highways as a function of lead
accumulation thought they mainly consider it as an effect of lead. Reduction in
pollen size, viability and shape reduction in pine pollens have been reported by
Fedatov et al. (1983). Reduced pollen viability in some vegetables as a function
of SO2 pollution in the vicinity of Mathura refinery was also reported by
Bhardwaj and Chauhan (1990). The present findings regarding the interaction of
pollen characteristics and urban pollutants are in confirmation with findings of
Joshi and Sikka (2002) and Chauhan et al. (2004). The highest reduction in
pollen size in D. regia as compared to other fours species can be attributed to
the pollen size. Because D. regia pollens are bigger in their size and thus they
require more photosynthate to maintain it, which is poorly available under
pollution stress. This might have resulted in higher reduction in size. Reduction
in pollen size due to high pollution in Pinus sylvestris have been reported
(Mamajev and Shkarlet 1972). Recently Chauhan et al. (2004) has also reported
change in morphology especially in ornamentations of pollen grains of C.
siamea pollen collected from high vehicular load. Such pollen grains failed to
show distinct colpi and reticulate sculpturing with comparison to less polluted
sites. They opined that this is due to the deposition of pollutants particularly,
suspended particulates matter due to heavy movement of automobiles.

But this interpretation does not seem to be logical because change in surface
characteristic might be a result of overall pollution load. Actually during
development stage; pollen grains are concealed in anther lobe. Hence these are
not coming in direct contact with particulate matter. Ornamentation and other
morphological features have been taken shape prior to anthesis. So these
changes might have occurred before anthesis.

In most of the studies carried out in areas exposed to industrially polluted, yet in
most instance it is accompanied by other pollutants and additive effects must be
reckoned with Bonte (1982). Nakada et al. (1976) showed the in vitro studies

23

indicates that the addition of SO2 to NO2 or O3 or HCHO, considerably increase
the percentage inhibition compared with the action of each product examined
separately.

There is little information available on the mechanism of action of SO2 on the
pollen tube. However Ma et al. (1973) have measured the pollen mitotic index
of Tradescantia paludosa treated in vitro by SO2 they assumed the SO2 broke
down the chromosomes of the pollen tube. Delayed and reduced floral yield of
carnation and geranium species have been reported along with vegetative
growth retardation (Feder 1970). Ozone induced inhibition in pollen
germination and pollen tube growth has been observed (Feder 1981). Work
done by Mumford et al. (1972) suggests that O3 induces the autolysis of
structural glycoproteins and stimulates amino-acid synthesis in pollen and
inhibited germination by 40-90 %.

Thus it can be concluded that the changes observed in present study in flowers
and pollens grains are the results of cumulative effect of urban air pollutants, i.e.
SO2, NOX and Photochemical oxidants along with particulates.

24

Air Pollution Impact on Fruits
2.1 Introduction

The union of the male and female generative cells, after pollination, to form the
fertilized egg leads to the formation of fruits and seeds. A fruit is the mature
female part specially ovary which may or may not include other parts of the
flower. The seed is the ripened ovule contained within the fruit. Later on in due
course of time germination of seeds give rise to new plants.

Seeds are typically composed of three parts the embryo, endosperm and the
seed coat. Fruits may contain one to several seeds. The term „fruit‟ and „seed‟
are often used loosely, for example the so called „seeds‟ of many members of
poaceae are actually one seeded fruits. There are different types of fruits,
depending on how they are derived. They may be fleshy, dry indehiscent,
dehiscent, aggregate etc. The fruits of Leguminoceae are derived from single
carpel with marginal placentation having one to many seeds. These fruits are
dry dehiscent or indehiscent and commonly called Pods.

Most angiospermic seeds have a seed coat derived from either two integuments
or single integument of the ovule. In bitegmic seeds the term „testa‟ is applied
only to the outer layer, formed from outer integument, the part formed from the
inner integument being the tegment.

Seed coat may be complex multilayered tissue or simply enlarged ovule wall.
This generally includes a hard, protective layer formed from all or part of the
testa. Corner (1976) has classified seed coat according to the position of this
mechanical layer. In exotestal seedcoat the mechanical layer is formed from
the outer epidermis of the outer integument and in endotegmic seed coat, it is
derived from the inner wall of the inner integument. Some times the mechanical
layer consists of one or more rows of elongated, palisade like cells, such as the
macrosclerides in the exotesta of many leguminoceae, which is the family under
study during the present research work.

Apart from the obvious mechanical protective function, to prevent destruction
of the seed by dehydration or predation, the seed coat often has important
subsidiary functions, usually related to dispersal. These may bear corresponding

25

specialized structures. Like presence of wings in wind dispersal seeds and
fleshy seeds for dispersal by animals.

Of the many seeds produced by a plant, only a small proportion survives.
Predation, rotting, falling in the wrong place or any of the many other natural
and man made hazards besetting a seed. Those that do survive will sooner or
later germinate.

While the seed is dormant, all its processes are slowed down so as to utilize
available limited food resources very economically to keep the embryo alive.
When the dormancy is broken and the conditions are favorable for germination,
the seed rapidly takes in water and the respiration rate rises back to normal as
cell starts to grow and divide. The area of greatest growth at first is the root
initial and young root soon pushes its way out through the seed coat. Such seeds
are called as germinated.

At germination the testa is ruptured and the radicle emerges through the
micropyle. The seedling is the most Juvenile stage of the plant, immediately
after germination, seedlings have a root (radicle) and a hypocotyls, which bears
the cotyledons and plumules bud. This bud produces the stem and leaves, which
soon resemble those of the mature plant. The cotyledons or seed leaves usually
differ from the first foliage leaves. In large seeded dicotyledons such as the
legumes the cotyledons are fleshy and swollen, with a food storage function.
The overall physiology and biochemistry of sexual reproduction i.e. flowering,
fruiting, seed setting and seed germination is influenced by various
environmental constrains of which air pollution is one of the most significant
factors. Looking to the deteriorating air quality the present study was planned to
assess the impact of urban air pollution on fruits and seeds of the selected plant
species.

2.2 Experimental
Apart from foliar injury plants also show changes in their reproductive parts
too, in response to polluted air. This study was aimed to know the effects of air
pollution on fruit morphology and seed quality. The colour, size and weight of
fruits and seeds along with seed count and viability were studied.

26


Mature pods of C. fistula, C. siamea, C. pulcherrima, D. regia and P. inerme
were collected during 2002, 2003and 2004 from the selected areas of Indore
city from a height of 3 to 4 meter. Colour of pods and injury symptoms on them
were recorded visually and compared with reference area.

2.2.1 Size of Pods

Pod size measurement was performed by taking 20 pods from five trees of each
test species brought to the laboratory in polythene bags. Thus 100 pods from
each species from every study area were collected. Length and Breadth of pods
were recorded with the help of a standards measuring tape. In case of C. fistula
in place of breadth diameter was measured.

2.2.3. Weight of Pods

Hundred pods each for year 2002, 2003 and 2004 were collected from different
pollution areas along with Low pollution area were dried in oven at 80º C for 24
hours and their dry weight was recorded using an electronic balance. The results
are presented as grams per pod.

2.2.4 Seed Count

The effect of airborne pollutants on seed per fruit of selected tree species was
also studied. For this purpose seeds were taken out from the pods collected or
dry weight measurement and seed number per pod was also recorded.


Seed viability was tested following Cottrell (1947) to test the viability imbibed
seed were cut, so that the embryo is bisected and then seed were placed in a
1.0% solution of 2,3,5 Triphenyl -2 H-tetrazolium chloride (TTC). Viable
embryo releases hydrogen ion during respiration, which combines with TTC,
imparting red or pink colour to seeds. The seeds in which embryo turned pink or
red after 24 hours were considered as viable and their number were recorded.
The test was conducted in petri plates containing filter paper. Four replicates of

27

25 seeds per petri plates were used for the study. The results are presented as
percent viability.

Like other aerial parts of the plant fruit are also remain exposed to polluted air
throughout their developmental span. This ranges from few months to years
depending upon the nature of plants. During this prolonged exposure they
interact with air pollutants resulting in the variation in various morphological
features like shape, size and colour.

2.3 Results


Like leaves the fruit also remain exposed to the ambient air during their
developmental period, thus they too showed response to polluted air. The pods
of all the test species collected from polluted sites appeared dark in colour as
compared to the pods collected from low pollution area, which were less dark
and shiny.

It was also observed that the colour of the pods growing in Industrial Pollution
area affected more than pods collected from Vehicular Pollution Area. In most
of pods their normal dark brown colour has turned in to dark brown to black due
to the interaction of pollutants and deposition of particulate matter on them.
Chlorotic and necrotic spots with tip burn were also observed in some pods of
C. pulcherrima in the polluted areas (Table 2.1, Plate-2.1 to 2.5).

Table 2.1: Colour of pods collected from different polluted areas of Indore city
Name of Plant Low Pollution Area Industrial Pollution Vehicular Pollution
species TPL* 308.02 g/m3 Area Area
TPL* 539.15 g/ m3 TPL* 506.81 g/ m3
C. fistula Blackish-brown Dark black brown Dark black brown
C. siamea Brownish Light brown Light brown
C. pulcherrima Brown Dark brown Dark brown
D. regia Dark black Dark black brown Dark black brown
P. inerme Shiny blackish-brown Blackish brown Blackish brown
*TPL -Total Pollution Load

28

Plate-2.1: Cassia fistula pods showing Plate-2.2: Cassia siamea pods showing
colour change and size reduction. colour change and size reduction.

Plate-2.3: Caesalpinia pulcherrima pods Plate-2.4: Peltoforum inerme pods
showing colour change and size showing colour change and size
reduction. reduction.

Plate-2.5: Delonix regia pods showing
size reduction.
2.3.2. Size of Pods

The polluted air has affected the size of the pods. There was a reduction in
length as well as breadth of the pods in plants growing in different polluted
sites. It is evident from the data presented in Table 2.2 and Fig. 2.1 that the
reduction in pod length was more in Industrial Polluted Area as compared to
Vehicular Polluted Area.

29

Table 2.2 : Length and Breadth Ratio of pods collected from different polluted areas of Indore city
Name of Y TPL*308.02 g/m3 TPL* 539.15 g/m3 TPL* 506.81 g/m3
Plant E
species A L B L/B L B L/B % % Red L B L/B % % Red
R Ratio Ratio Red (B) Ratio Red (B)
(L) (L)
C. S1 41.00 8.00 5.12 34.85 7.34 4.74 37.87 7.87 4.81
fistula S2 40.32 7.99 5.04 38.92 7.54 5.16 36.45 7.33 4.71
S3 41.24 8.09 5.09 37.99 7.42 5.11 39.20 8.13 4.82
A 40.85 8.02 5.09 37.25 7.43 5.01 8.81 7.35 37.84 7.91 4.78 7.36 1.37
±0.24 ±0.10 ±0.20 0.20 ±1.10 ±0.48 ±0.52 ±0.68 ±0.49
C. S1 17.42 1.20 14.51 15.24 1.1 13.85 16.27 1.20 13.5
siamea S2 17.36 1.30 13.35 14.74 0.9 16.37 16.98 1.10 15.4
S3 17.28 1.20 14.40 16.40 0.8 20.50 16.54 1.10 15.0
A 17.35 1.20 14.08 15.46 0.9 16.90 10.89 18.18 16.59 1.10 14.67 4.38 8.33
±0.10 ±0.01 ±0.08 ±1.48 ±0.01 ±3.25 ±0.59 ±0.01 ±0.67
C. S1 10.1 1.5 6.73 9.54 1.1 6.81 9.62 1.40 6.87
pulche- S2 9.74 1.4 6.95 8.99 1.3 6.91 9.70 1.32 7.34
rrima S3 10.3 1.6 6.27 9.39 1.5 6.26 9.02 1.20 7.51
A 10.04 1.5 6.65 9.30 1.4 6.66 7.37 6.66 9.44 1.30 7.2 5.97 13.3
±1.29 ±1.11 ±1.35 ±1.29 ±1.10 ±1.54 ±1.78 ±1.15 ±1.29
D. S1 39.25 3.15 12.46 37.46 3.10 12.08 38.24 3.12 12.25
regia S2 38.00 3.50 10.85 37.89 3.48 10.88 38.43 3.34 11.50
S3 37.75 3.60 10.48 38.20 3.56 10.73 37.09 3.52 10.70
A 38.33 3.48 11.05 37.85 3.43 11.06 1.25 1.45 37.42 3.31 11.5 1.06 4.88
±0.83 ±0.41 ±0.56 ±1.20 ±1.38 ±1.06 ±0.42 ±0.08 ±1.08
P. S1 9.60 2.2 4.36 7.43 1.7 4.36 8.29 1.9 4.36
inerme S2 9.77 2.0 4.88 8.24 2.00 4.12 8.74 2.1 4.16
S3 9.82 2.1 4.67 9.47 1.9 4.98 9.59 1.9 5.04
A 9.73 2.1 4.64 8.38 1.85 4.60 14.40 11.90 8.87 1.9 4.44 8.83 9.52
±0.43 ±0.02 ±0.58 ±1.28 0.42 0.28 ±0.93 0.20 0.43
*TPL -Total Pollution Load, L – Length, B – Breadth, Red – Reduction,
Sampling year - S1 –2002, S2 –2003, S3–2004 ; A – Average Values

Maximum reduction in pod length was noted in P. inerme where it was 14.40 %
and 8.83% respectively in IPA and VPA with reference to LPA. Whereas
minimum reduction was recorded in D. regia where the values were 1.25 % and
1.06% respectively in IPA and VPA. The rest of two species of Cassia appeared
more or less affected similarly at both sites.

The breadths of the pods were also found decreased in all the species.
Maximum reduction in breadth of the pod was recorded in C. siamea (18.18%)
and C. pulcherrima (13.30%) respectively in IPA and VPA. Regarding breadth
of pod C. fistula found to be affected least in VPA.

30

The L/B ratio of pods was also changed (Table 2.2). There was a slight increase
in the ratio for C. siamea, C. pulcherrima and D. regia. However this ratio
decreased in P. inerme and C. fistula showed that the pods breadth was
comparatively more affected than length in most of the species studied. Thus it
can be concluded that there was overall growth retardation in pods of all the test
species growing in polluted areas.


Dry weight of pods is presented in Table 2.3. It can be seen from the table that
dry weight of pods has also been reduced in all the plant species. The maximum
reduction was observed in C. siamea i.e. 44.0 % in IPA and 30.30 % in VPA
and minimum in C. pulcherrima, i.e 8.96% in IPA and 8.79% in VPA
respectively. Whereas D. regia and P. inerme showed more than 20 % reduction
in dry weight. Areas wise there was more reduction in pod dry weight in
Industrial area than Vehicular area (Fig. 2.3).

Table 2.3 : Dry weight of pods collected from different polluted areas of Indore city
Name of LPA IPA VPA
Plant Year TPL* 308.02 TPL* 539.15 % Reduction TPL* 506.81 % Reduction
species g/m3 g/m3 g/m3
C. fistula 2002 67.92 51.78 50.88
2003 65.70 54.48 53.74
2004 63.82 52.72 55.34
Avg. 65.81±2.80 52.99 ± 1.25 19.48 % 53.32 ± 3.40 18.97 %
C. pulcherrima 2002 12.37 11.98 9.09
2003 11.69 10.23 10.87
2004 10.42 9.17 11.48
Avg. 11.49±0.65 10.46 ± 1.34 8.96 % 10.48 ± 1.02 8.97%
C. siamea 2002 12.97 7.28 8.98
2003 13.11 7.39 9.59
2004 13.53 7.47 9.04
Avg. 13.20±0.05 7.38±0.006 44.0 % 9.20 ±0.05 30.30%
D. regia 2002 77.93 51.27 57.64
2003 68.43 54.25 51.37
2004 67.71 56.79 58.45
Avg. 71.35±2.95 54.10±5.08 24.17% 55.82  2.95 21.76%
P. inerme 2002 10.37 8.52 8.63
2003 10.87 6.56 7.48
2004 9.24 7.88 7.69
Avg. 10.16±0.09 7.65±0.66 24.70% 7.93  0.15 21.91%
* TPL - Total Pollution Load, ** Avg. - Average of 100 pods

31

Fig. 2.3 : % reduction in dry weight of pods over LPA.
50

C.fistula
45 C.siamea
C.pulcherrima
D.regia
40
P.inerme

35

30

Reduction
25

%
20

15

10

5

0
IPA VPA

2.3.4. Seed count

A perusal of Table 2.4 to 2.8 indicates that there was a reduction in seed
number, which ranges from 20.55 % to 3.15 %. The maximum lowering in seed
per pod was noted in C. siamea in Industrial area, while the minimum reduction
was recorded for C. pulcherrima in VPA. The response of C. fistula, D. regia
and P. inerme was almost same in both the polluted sites (Fig. 2.4).

Fig. 2.4 : % reduction in Seed/pod over LPA.
25

C.fistula
C.siamea
C.pulcherrima
D.regia
20
P.inerme

15
% Reduction

10

5

0

IPA VPA

Further it is also evident that number of unhealthy seeds per pod is high in both
the polluted sites in comparison with reference area. It clearly indicates that
whatever be the nature of the pollutant it adversely influenced the seed number
and quality.

On the overall basis it can be stated that the colour, size, shape, weight and
number of seeds per pod all were adversely affected by air pollution prevailing

32

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