Diversity of Lichens and Host Plant Species in University of Uyo Campuses

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1 Article International Journal of Modern Plant & Animal Sciences, 2014, 2(1): International Journal of Modern Plant & Animal Sciences Journal homepage: ISSN: Florida, USA Diversity of Lichens and Host Plant Species in University of Uyo Campuses Denise, E.M. and Thompson, E. O. Department of Botany and Ecological Studies, University of Uyo, P.M.B. 1017, Uyo, Akwa Ibom State, Nigeria * Author to whom correspondence should be addressed; mukoroemmanuel01@gmail.coms Article history: Received 9 October 2014, Received in revised form 26 November 2014, Accepted 5 December 2014, Published 9 December Abstract: Lichens are the association between specific ascomycetes (a fungus) and certain genera of either green algae or cyanobacteria. In lichen, the fungal partner is termed mycobiont and the algal partner is termed photobiont. In the past, the lichen symbiosis was considered to be a mutualistic interaction. It recently has been found that lichen forms only when the two potential partners are nutritionally deprived. This relationship between the two partners has coevolved to the point where lichen morphology and metabolic relationships are extremely stable. In this study, Lichens and growth dispersion in host plant species in the three campuses of University of Uyo was not uniform. Foliose and Crustose lichens were abundant in University of Uyo main campus, they were mostly epiphytic, they vary in colour, nature of attachment and texture (some powdery, some dry, some leafy and others hairy). At town campus, Fruticose lichens were present which was absent in the first site, Crustose were also present along with Foliose. In the Third site (Annex Campus) Fruticose was absent and Crustose was more abundant than Foliose. Keywords: Diversity, Epiphytic lichen and Host plant species 1. Introduction It was once said by the great lichenologist Trevor Goward: Lichens are a case of fungi that have discovered agriculture. Lichens are peculiar growths that develop when two unlike organisms

2 51 come together in a mutualistic close association. The symbionts are a member of the Ascomycetes or sac fungi (from the Kingdom Fungi) and a green alga (in the Kingdom Protoctista) or a cyanobacterium, formally blue-green algae. The fungus provides a physical structure for the relationship and the cyanobacterium (which is slimey and has no structure) provides the food because it can photosynthesize. The carbohydrates in this food help produce new growth, which looks different than the two hosts. This new vegetative body that is produced is called the thallus. There are many variations of this relationship. For example, sometimes club fungi and brown algae are involved, rather than sac fungi and green algae. Although lichens look like a single organism, it is actually a dual organism. The occurrence of lichens may date from the early Devonian (400 million years ago) (Taylor et al., 1995). As the earliest colonizers of terrestrial habitats on the earth, lichens are amongst the most successful forms of symbiosis (Galloway, 1994; Seaward, 1997). According to Ahmadjian (1993), lichen may be described as an association between a fungus usually an ascomycete but in a few cases a basidiomycete or deuteromycete and one or more photosynthetic partners generally green algae or cyanobacteria. In all lichens, the fungus forms a thallus or lichenized stroma that may contain unique secondary compounds. In a lichen, the fungus lives parasitically on the alga which manufactures food by virtue of the chlorophyll present in the cells while the alga enjoys the protection afforded by the fungal envelop to live in very dry conditions. The fungus forms most of the lichen thallus (body). The fungus surrounds hundreds of photosynthetic partners and holds them in place. In the laboratory researchers can isolate the fungal and algal components of some lichens and grow them separately in appropriate culture media. The algal member grows more rapidly when separated whereas the fungus grows more slowly and requires many complex carbohydrates. Neither organism resembles lichen in appearance when grown separately (Smith, 2007). Lichen is a composite organism consisting of a fungus (the mycobiont) and a photosynthetic partner (the photobiont or phycobiont) growing together in a symbiotic relationship (Dobson, 2000). The photobiont is usually either a green alga (commonly Trebouxia) or cyanobacterium (commonly Nostoc) (Dobson, 2000). The morphology, physiology and biochemistry of lichens are very different from those of the isolated fungus and alga in culture. Lichens occur in some of the most extreme environments on Earth arctic tundra, hot deserts, rocky coasts, and toxic slag heaps. However, they are also abundant as epiphytes on leaves and branches in rain forests and temperate woodland, on bare rock, including walls and gravestones, and on exposed soil surfaces (e.g., Collema) in otherwise mesic habitats. Lichens are widespread and may be long-lived (Morris and Purvis, 2007). However, many are also vulnerable to environmental disturbance, and may be useful to scientists in assessing the effects of

3 52 air pollution, ozone depletion, and metal contamination. Lichens have also been used in making dyes and perfumes, as well as in traditional medicines. It has been estimated that 6% of Earth's land surface is covered by lichen (Geoffrey, 2010). Ahmadjian (1993) stated that according to the form of the plant body (thallus) lichens have been classified into three groups including: Crustose or crustaceous lichens - which form a thin crust over the rocks, soils and trees on which they grow, they are partly or wholly adherent to the substratum, the colour may be green, orange, black or yellow e.g Graphis, Lecanoria, Lecidea and Haematomma. Nash (1996) stated that, the crustose lichens can further be classified into five groups Powdery or Leprose (They are powdery in appearance and are very difficult to separate into phycobiont and mycobiont e.g Lepraria), Endolithic (They grow inside rock and help in weathering of rock e.g Buellia), Endophloeodic (they grow on leaves and stems of plants), Squamulose (scale-like lichens which appears as partially separated from its substrate e.g. Catapyrenium), Effigurate (thallus of Effigurate has radially arranged and long marginal lobes e.g. Caloplaca). Foliose or foliaceous lichens - They occur as flat and leaf-like lobed thalli attached to the rock and twigs by means of rhizoid-like outgrowth called rhizinae. This develops from the lower surface of the thalli. The common representatives are physcia, Parmelia, Peltigera and Collema etc. It is one of the most conspicuous type of growth of lichens. Sometimes, this type of lichen forms smaller lobes as in Physcia or Parmelia and sometimes forming huge plates attached to the centre e.g. Umbilicaria. Fruticose lichens are shrubby lichens with plant-like growth pattern and also can hang from the substrate. They are round in cross section with identical top and bottom (Santis, 2002), that is they are cylindrical or ribbon-like thallus which is either upright (Evernia, Cladonia) or pendulous (Usnea). The objective of this paper is to identify the different growth forms found in lichens and their distribution. 2. Materials and Methods In order to successfully examine the growth form and spatial arrangement of lichens in the three (3) campuses of University of Uyo, the following materials were employed. i. Camera ii. iii. iv. Writing materials (Biro and Notepad) A textbook of Fungi and Lichens Ethno botany textbook

4 Methods The method involved movement from plant to plant examining the leaves, stem and whole plant in order to observe the lichens present and their host plants. However, the frequency of occurrence of the different classes of lichens was also noted. Pictures of the lichens were taken and most of the plants they were found were identified. The procedure was repeated for the different plants in the campuses. When identifying the lichens, foliose lichens were confirmed by trying to remove it from the substrate by hand. The observation was that if it was powdery or unable to be removed without destroying it, it was Crustose but if they were easily removed, they were foliose. The flat ones were difficult to be removed without being destroyed and they were regarded as Crustose. Fruticose was observed by looking out for its hairy outgrowth. 3. Results and Discussion At exactly 11:35am on 31st April, 2014, we left for the bush in University of Uyo main campus. In front of Faculty of Science Block, foliose lichens that were detached from the substrate was observed and another was seen attached to dead tree. Inside the bush opposite Faculty of Science block, an epiphytic light green coloured crustose was seen at the base of the stem bark of a tree called Afuo in Ibibio, Camwood in English i.e. Baphia nitida Lodd. (Plate. 1). Plate 1: Crustose Lichens Host plant (Baphia nitida) However, moving further the bush, foliose lichens were found as epiphytes on Elaeis guinensis Jacq., English Name: Oil Palm and Ibibio name: Eyop. (Plate 2 a and b)

5 54 (a) (b) Plate 2: Foliose Lichens on Elaeis guinensis (a) (b) Plate 3: Crustose lichen on basal region of host plant (Baphia maxima) Lichens were not found on the area between the hostel site and Engineering, this was because the area was disturbed by farming activities. In front of Engineering Faculty hostel, there were some epiphytic foliose lichens on the ornamental trees that had parallel leaves and thick bark. (Plate. 4a and b) Second Site: University of Uyo, Town Campus At Town Campus, Foliose lichens were epiphytic on the stem of Tectona grandis at the ravine site. Fruticose Lichen was seen in another stand of Tectona grandis at the same site.

6 55 Plate 4: Foliose Lichens Plate 5: Host Plant Plate 6: Crustose lichen on Tectona grandis Another host plant for crustose lichen was the epiphyte (Gliricidia sepium (Jacq.) Plate 7a and b. Powdery crustose were found on Lemon tree behind the building of guardian and counseling department. Hair-like fruticose lichens were found on the ornamental plants Izora coccinea Plate 9 at the front of Directorate of Academics block and Common Wealth building while crustose lichens were found on the Izora coccinea beside fine art department. Plates 10 and 11.

7 56 (a) Plate 7: Crustose lichen (b) Host plant 8: Gliricidia sepium Plate: 9 Plate: 10 Plate: 11

8 Third Site: University of Uyo, Annex Campus Numerous Crustose lichens were found on the tress in this site. There were mainly epiphytic crustose lichens. Host plant species include Pinus sylvestris for crustose form (Plate 12), Mangifera indica behind annex Library was favorably inhabited by Foliose lichens (Plate 13). Plate 12: Crustose on Pinus sylvestris Plate 13: Foliose lichen on Mangifera indica Also crustose lichens and foliose types were found on Terminalia catapa on the same field behind Annex library (Plate 14). Plate 14: Crustose lichen on Terminalia catapa

9 58 Crustose lichen was found epiphytic on Croton zambesicus (Muell Arg.)(Thunder plant) in front of Agric Extension Department. 4. Conclusion Plate 15: Crustose lichen on Croton zambesicus It can be concluded that lichens are diverse in their growth form and distribution. As seen above, both Foliose and Crustose lichens were abundant in University of Uyo campuses. There were mostly epiphytic, they vary in colour, nature of attachment and texture (some powdery, some dry, some leafy others hairy). At town campus, Fruticose lichens were present which was absent in the first site, crustose were also present along with Foliose. In the Third site (Annex Campus), Fruticose was absent and Crustose was more abundant than Foliose. Therefore the lichen types present were non uniform in the three sites. Recommendation Further work on the identification on the individual species of lichens is recommended. Also distribution pattern should be study critical to ascertain factors that promote their distribution. Reference Ahmadjian, V. (1993). Definition of Lichen. In: The Lichen Symbiosis (Introduction). John Willey and Sons, Inc., New York, pp

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