SUMMARY AND CONCLUSIONS

Transcription

1 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. They are used as Chapter-5: SUMMARY AND CONCLUSIONS 83

2 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. To collect and make a list of fern and fern allies growing in Mahabaleshwar forest area. 2. To study microclimatic and rhizosphere soil properties of selected medicinal ferns 3. To conserve some medicinal ferns in botanical garden under Pune climate. 4. 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 All localities from the Mahabaleshwar that are ideally favorable for Chapter-5: SUMMARY AND CONCLUSIONS 84

3 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. Chapter-5: SUMMARY AND CONCLUSIONS 85

4 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 Chapter-5: SUMMARY AND CONCLUSIONS 86

5 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. Chapter-5: SUMMARY AND CONCLUSIONS 87

6 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 %. (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. Chapter-5: SUMMARY AND CONCLUSIONS 88

7 (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. Chapter-5: SUMMARY AND CONCLUSIONS 89