Chapter-5
SUMMARY AND CONCLUSIONS
Pteridophytes are one of the most ancient plants. They appeared over 300 million years
ago. This was around the time when coal was being formed. These are non-flowering, vascular
and spore-bearing plants, which include ferns and fern-allies. These are classified under
cryptogams. This is because ferns reproduce by spores, which form in bundles called sori, on the
underside of the fertile leaves. The spores and the reproductive process are thus hidden from
view. Since the reproduction of ferns is executed by spores instead of seeds and considered as
lower vascular plants. Ferns occur all over the world and only the group of higher vascular plants
to have two independent living stages to their lifecycles. (i) the spore producing stage and (ii) the
gametophyte stage.
Plants are global resource. Human societies are using plants and various plant parts for
various purposes like medicinal, ornamental, commercial etc. The pteridophytes constitute the
primitive vascular plant group and found scattered all over the world. Actually not more
attention is given towards the uses of ferns yet it possesses equal economic importance including
medicinal uses (Mannan et al., 2008).
India is among twelve mega-diversity centers. Eastern Himalayas and Western Ghats are
two hotspots. It is with a highly predictable climate has a rich pteridophytic flora. They bloom
well in tropical, subtropical, and temperate forests. Pteridophytic survey of different localities
has been frequently convinced in various parts of India. Most of Southern Indian Pteridophytes
are found in Western Ghats, which has been explored by many workers. Exhaustive systematic
survey of pteridophytic localities for many years revealed the occurrence of 59 species from 35
genera in Western Ghats of Maharashtra. Many taxa of Pteridophytes have been lost or
eradicated from Western Ghats due to the present pace of rapid industrialization and exploitation
of natural resources. The previous
work indicate that the medicinal plants specially the
flowering plants are given the more importance in these contents, non-flowering plants
particularly fern and fern allies are ignored by scientists. Many ferns are medicinally important
and many are used by tribal people as remedy for various diseases.
Chapter-5: SUMMARY AND CONCLUSIONS
They are used as
83
ornamental plants in indoor or outdoor conditions. Some ferns are used in phyto-remediation
and some are important from industrial point of view.
Frequent landslides bring about an ecological disequilibrium, which today threatens the
fern species. Mostly the fern species are shade and moisture loving and grow in the interiors of
forests. If there is any disturbance of vegetation, it affects on the on the destruction of ferns. In
certain forests the pteridophytes have been completely eradicated due to the destruction of
forests to make way for crop cultivation. Due to over exploitation of pteridophytic taxa there is
need to conserve them and for that necessary steps are desired to be taken for their conservation
in botanical gardens in different parts of the country before many of them become endangered or
permanently extinct. Any disturbance inflicted on ferns is sure to affect the biological
equilibrium in the forest ecosystem. Apart from conserving ferns in situ, certain threatened
species should be conserved ex situ by cultivating and propagating in gardens and green houses
at different altitudinal levels with a view to re-establishing them in the wild.
Hence, in present investigation it was decided to conduct a survey to list the
pteridophytes growing in Mahabaleshwar forest area , study their habitats and conserve
some of the important species in botanical garden under Pune climatic conditions.
Aims and objectives
1.
2.
3.
4.
To collect and make a list of fern and fern allies growing in Mahabaleshwar forest area.
To study microclimatic and rhizosphere soil properties of selected medicinal ferns
To conserve some medicinal ferns in botanical garden under Pune climate.
To study eco-physiology of selected ferns in their natural habitat and new environments
The thesis is divided in four chapters- these are (i) Introduction and Review of literature
(ii) Ferns of Mahabaleshwar (iii) Acclimatization of medicinal ferns in Botanical Garden and
(iv) Eco-physiological studies of medicinal ferns. A brief summary and conclusion is also given
in Chapter-v.
The literature surveyed is appended as bibliography at the end of the thesis. A
brief introduction, objectives, hypothesis, materials and methods are given chapter wise.
MATERIALS AND METHODS
Survey of medicinal fern and fern allies of Mahabaleshwar
An extensive floristic survey of Mahabaleshwar forest was carried out between June
2005 and October 2010. All localities from the Mahabaleshwar that are ideally favorable for
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84
growth of fern flora were observed. Every possible area, which supports the growth of fern flora
in the forest region, was visited frequently for five years. To conduct survey of ferns and fern
allies, ten sites (Ambenali -Pratapgad Fort, Tapola dam, Panchgani, Old Mahabaleshwar,
Lingmala fall, Arthur seat point, Venna lake side) were selected. Five plots of 10m × 10m were
sampled from each of these sites in a random manner. Representative samples of pteridophytes
were collected and preserved as herbarium specimens. Epiphytic ferns, aquatic ferns and ferns
found on the walls (i.e. those that were not found within the plots but were present in vicinity of
the sites) were also sampled. Visits to school campus, college campus, hotel promises and
gardens were also made to note the uses of ferns.
The species were recorded, photographed and identified with the help of different
floras. The voucher specimens were collected for the preparation of herbarium specimens for
identification. Preserved specimens are deposited in Department of Botany, Fergusson College,
Pune (MS).
During the survey, possible threats to the ferns of this area were also identified and
recorded. Damage and destruction were considered as major threats. The interviews were
conducted in an informal manner with local people, villagers and visitors to get an idea of
collection of ferns.The general and medicinal uses of the ferns and fern allies were recorded from
local people and confirmed from the literature.
Based on medicinal uses eight fern species were selected for conservation. These include
Adiantum capillus-veneris L., Adiantum lunulatum Burm.f., Tectaria macrodonta (Fee) C. Chr.,
Pteridium aquilinum (L) Kuhn., Microsorium punctatum (L) Copel., Pteris vittata L.,
Cheilanthes farinosa Kaulf. and Christella parasitica (L) Lev. The habitats of these selected
ferns were marked in Mahabaleshwar forest to study microclimatic conditions and soil
properties.
The habitats of selected ferns were marked in Mahabaleshwar forest to study
microclimatic conditions. Light intensity, Percent humidity and temperature were noted every
after 15 days for the entire year. Soil sample from the rhizosphere of selected ferns were
collected and brought to laboratory and analyzed for pH, electrical conductivity, organic matter,
and organic carbon and soil minerals.
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Acclimatization of medicinal ferns under botanical garden
The method used for acclimatization of ferns in present investigation was designed based
on microclimatic conditions and substratum (rhizosphere soil) observed in their habitats at
Mahabaleshwar. Earthen or cement/plastic pots were used for acclimatization of ferns.
The pot mixture was prepared by mixing coarse sand, brick pieces, shredded moss, rhizosphere
soil, garden soil and compost. The proportion was 1:1:1:10.5:0.5:1. The content was mixed
thoroughly and pot was filled with pot mixture. The rhizomes of selected ferns (5 numbers)
were planted in each pot in such way that the growing points of the rhizomes will remain open.
The pots were distributed in three sets and each set has minimum 5 pots. The pots were
maintained
in conditions as mentioned in three different methods. These conditions are: (1)
Under shade near the northern side of wall. (2) Pots were kept in big sized perforated polythene
bags. (3) Pots were kept near humidifier.
A humidifier, constructed of PVC pipe was used to
maintain humidity near the culture site. To construct a humidifier a perforated 3-inch diameter
100 cm height pipe was filled with brick pieces, fitted in container containing water, and used to
maintain the humidity near the pots.
Different parameters like humidity, temperature and light intensity were recorded
regularly near the pots to maintain the required climatic conditions at conservation site. The pots
were kept on northern side of the wall to avoid direct sunlight. Pots were watered regularly to
maintain the humidity. The sprouting of rhizome was noted regularly. The ferns grown under
these methods were observed for their growth and percent survival was determined for each fern
species.
Eco-physiological studies of medicinal ferns
The ferns, which are acclimatized at Pune conditions, were studied further for the
characters like rhizome sprouting time., plant height, plant spread, vegetative growth period up
to formation of sori (days required for sori formation), reproductive period (time from sori
formation to sori maturation) and rhizome dormant duration (days). All above characters were
studied from the selected ferns from Mahabaleshwar forest (habitats initially marked for the
collection of rhizomes) as well as ferns acclimatized under Pune conditions. The medicinal ferns
growing in their natural habitats at Mahabaleshwar and acclimatized under Pune climatic
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86
conditions were studied for photosynthetic pigments, carbohydrates, proteins, phenols and some
antioxidant enzymes like catalase, peroxidase, polyphenol oxidase, ascorbic peroxidase and
superoxide dismutase. All the biochemical analyses were carried out from mature fertile fronds
(with sori). Exactly 0.5 g fresh fronds were extracted with suitable buffers/solvents and used for
analysis of various biochemicals and enzymes following standard methods.
The
experiments are replicated in three set and values are mean of three set. The data
obtained was subjected to statistical analysis and ANOVA was calculated.
The critical
difference i.e. CD values are given in the table to know the statistical significance.
SIGNIFICANT FINDINGS
Survey of fern and fern allies of Mahabaleshwar
(1) The overall study of the present investigation represented in the conservation of fern
diversity of Mahabaleshwar region, which have 43 species of ferns and fern-allies come
under 27 genera and belonging to 21 families were recorded. Most of the pteridophytes are
listed in the category of endemic and rare species. Therefore, there is an urgent need to
conserve these fern germplasm of primary land vascular plants. Therefore, it is concluded
that though exploitation of pteridophytic taxa for their economic value is necessary, steps are
desired to be taken for their conservation in botanical gardens before many of them become
endangered or permanently extinct.
(2) The possible threats to this eco-sensitive group are clear responsibility to conserve
them. Therefore, the conservation measures should be extended for ex situ conservation for
the ferns and fern allies.
(3) It is also concluded that, antimicrobial activity of plants extracts of these fern plants and their
active constituents must be identified, which would be helpful in treating various kinds of
diseases. Crude extracts as well as different active phyto-constituents of these plants need to
be explored with in-vitro and in-vivo assay techniques to find out the efficacy for their
possible therapeutic utility.
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Acclimatization of medicinal ferns in Botanical garden under Pune climate
(1) The substrate analyses of ferns clearly indicate that some ferns require acidic substratum and
some grow better in alkaline soils.
(2) The ferns like Pteridium aquilinum and Microsorium punctatum are found growing in open
spaces under sunny situations can be considered as light demanding species, which prefer
substratum with low soil P values, while Tectaria macrodonta growing under shady but
exposed places prefer soils or substratum with moderate P.
(3) The ferns like Pteridium aquilinum, and Microsorium punctatum are found growing in open
spaces under sunny situations are most of the light demanding species, which prefer a soil
with low N and P content. Fern species like Pteris vittata, Microsorium punctatum and
Adiantum capillus-veneris were indicators of a high soil pH, while Pteridium aquilinum
preferred more acidic to acid soils. Tectaria macrodonta, Cheilanthes farinosa and Christella
parasitica grow on moderately acidic substratum.
(4) Ferns require coolest place and sufficient water for the growth and these environmental
situations were provided by the bricks, moss and shady conditions of the wall. As ferns were
provided with all the necessary environmental conditions for the growth, they were showing
the luxurious growth under Pune climatic conditions. Total seven species viz. Adiantum
capillus-veneris L, Adiantum lunulatum L., Tectaria macrodonta (Fee) C. Chr., Microsorium
punctatum (L) Copel., Pteris vittata L., Cheilanthes farinosa Kaulf.,
and Christella
parasitica (L) Lev. showed sprouting and survival - ranged from 50-70 %.
(5) Total six species taken for further multiplication, these all gave best response to method –II
Best response to method II- indicates requirement of proper soil conditions,
pH and
optimum moisture for the survival and rapid growth.
Eco-Physiological studies of medicinal ferns
(1) All the fern species viz. Adiantum phillipensis, Tectaria macrodonta, Pteris vittata,
Microsorium punctatum, Christella parasitica and Cheilanthes farinosa showed decrease in
photosynthetic pigments, soluble sugars and proteins.
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(2) The decrease in total photosynthetic area and chlorophyll pigments could be the main reason
for reduced carbohydrates and proteins. The phenols were increased in all the species under
Pune climatic conditions.
(3) The climatic conditions like higher temperature and low humidity as well as changed soil
parameters and soil microbes might have influenced polyphenol synthesis.
(4) Accumulation of proline and reducing sugars and
enhanced antioxidant enzymes might
have contributed to the survival and acclimatization of ferns under changed environment. All
the acclimatized ferns are showing the good response towards the selected parameters. They
are showing the luxurious growth under Pune conditions in the selected characters.
CONCLUSIONS
(1) Total 43 species of ferns and fern-allies observed in Mahabaleshwar, these come under
27 genera and belonging to 21 families. Most of the pteridophytes are listed in the
category of endemic and rare species. Hence, these must be conserved through in-vitro or
in-vivo methods.
(2) Most of the ferns are reported as medicinally, ethno-medicinally important. Some ferns
are also reported to have insecticidal and antimicrobial activity, hence the fern frond
extracts and their active constituents must be identified, which would be helpful in
treating various kinds of diseases. Crude extracts as well as different active phytoconstituents of these plants need to be explored with in-vitro and in-vivo assay techniques
to find out the efficacy for their possible therapeutic utility.
(3) The
medicinal ferns can be conserved easily in botanical garden, if proper climatic
conditions are mimicked and manipulated as per the microclimate available in natural
habitats.
(4) Accumulation of proline and reducing sugars and enhanced antioxidant enzymes
contribute to the survival and acclimatization of ferns under changed environment.
(5) All the acclimatized ferns are showing the good response towards the selected
parameters. They are showing the luxurious growth under Pune conditions in the selected
characters.
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