Department of Botany
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Item ASYMBIOTIC SEED GERMINATION, MYCORRHIZATION AND SEEDLING DEVELOPMENT OF ACAMPAE PRAEMORSA (ROXB.) BLATT. & MC CANN, A COMMON SOUTH INDIAN ORCHID(Elsevier- Asian Pacific Journal of Reproduction, 2013-06-20) Sathiyadash K; Muthukumar T; Bala Murugan S; Sathishkumar R; Uma E; Jaison S; Priyadharsini PTo develop conservation strategies for orchid species. Methods Seeds of Acampae praemorsa (Roxb.) Blatt. Mc Cann ( A. praemorsa ) were obtained from mature pods collected from Velliangiri hills and germinated on Murashige and Skoog (MS) medium supplemented with various concentration of Benzylaminopurine (BAP). Results Maximum seed germination (85%) was observed on MS media supplemented with 2 mg/L BAP. Seed germination percentage increased with increasing concentrations of BAP (0.5 mg/L to 2 mg/L), but 3 mg/L of BAP inhibited seed germination. Variations observed were significantly ( P ex vitro conditions. Conclusions In present study all the mycorrhizal seedlings survived, because orchid mycorrhizal fungi enhance growth of orchid plantlets and present study gives an effective protocol for seed germination and plantlet regeneration from immature seeds which can be used for establishing A. praemorsa populations in Velliangiri Hills and elsewhere.Item MORPHOLOGY, ANATOMY AND MYCORRHIZAE IN SUBTERRANEAN PARTS OF ZEUXINE GRACILIS (ORCHIDACEAE)(University of Murcia, Spain-Anales de Biologia, 2011-12-14) Muthukumar T; Uma E; Karthikeyan A; Sathiyadash K; Jaison S; Priyadharsini P; Ishworani C; Muniappan VZeuxine gracilis (Berda) Bl., is an endemic, terrestrial green orchid whose morphology, anatomy and mycorrhizal status is unknown. So we investigated: (a) root and rhizome anatomy; (b) root hair characteristics and mycorrhizal colonization patterns in Z. gracilis plants collected from Western Ghats region of southern India. The prominent anatomical characters in the roots were: absence of velamen, spiranthosomes, and the presence of single layered exodermis and nine arched protoxylem. The rhizome had an uniseriate epidermis, abundant spiranthosomes in the inner cortical cells, a distinct endodermis with casparian strips and biseriate vascular bundles. The presence of fungi both in the roots and rhizomes was revealed. The entry of fungi was chiefly through root hairs and through epidermis in the rhizome. Fungi formed pelotons and monilioid cells in the root cortex. Additionally, arbuscular mycorrhizal (AM) fungi characterized by the presence of aseptate hyphae, vesicles and spores were present occasionally in roots. The lack of arbuscules in Z. gracilis indicated the AM to be non functional.Item THE MYCORRHIZAL STATUS OF SOUTH INDIAN EPIPHYTIC ORCHIDS(The Postgraduate & Research Department of Botany, St. Thomas College, Kozhencherry, Kerala, India, 2009-10-28) Sathiyadash K; Uma E; Muniappan V; Sarah jaison; Muthukumar TThe study is to screen certain orchid species growing naturally in southern India for their mycorrhizal status and to assess the role of root morphology in determining the mycorrhizal status of orchidsItem ARBUSCULAR MYCORRHIZAL FUNGAL ASSOCIATIONS IN ZINGIBERACEAE AND COSTACEAE(The Postgraduate & Research Department of Botany, St. Thomas College, Kozhencherry, Kerala, India, 2009-10-28) Uma E; Sathiyadash K; Muniappan V; Sarah jaison; Muthukumar TWe provide information on the AM fungi incidence exclusively in Zingiberaceae and Costaceae, which will provide an opportunity to extend our knowledge on the AM association in these plant familiesItem ARBUSCULAR MYCORRHIZAL (AM) AND DARK SEPTATE ENDOPHYTE (DSE) FUNGAL ASSOCIATION IN LYCOPHYTES AND FERNS OF THE KOLLI HILLS, EASTERN GHATS, SOUTHERN INDIA(American Fern Journal, 2014) Muthuraja R; Muthukumar T; Sathiyadash K; Uma E; Priyadharsini PWe examined the extent and type of arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal associations in three lycophyte and 44 fern species collected from three different sites in the Kolli Hills, Eastern Ghats, southern India. Of the 47 plant taxa (belonging to 21 families and 33 genera) examined, 46 had AM fungal and 33 had DSE fungal associations. But, fungal structures were absent in the aquatic fern Azolla pinnata (Azollaceae). This is the first report of AM and DSE fungal status for 16 and 28 species, respectively. Among terrestrial lycophytes and ferns, 26 species had dual association of both AM and DSE fungi, whereas 11 species had only AM fungal association. Vittaria elongata from epiphytic habitats had dual association of AM and DSE fungi. Likewise, Cheilanthes tenuifolia (saxicolous or terrestrial), Cheilanthes opposita, Lepisorus nudus, Pyrrosia lanceolata (terrestrial or epiphytic), and Asplenium lanceolatum (saxicolous or epiphytic) examined from different sites or habitats also had dual association of AM and DSE fungi. Seventy two percent of the mycorrhizal lycophytes and ferns had intermediate-type AM and 15 percent had both Paris- and intermediate-types at different sites. Significant variations in AM fungal structures were evident in 16 ferns occurring in two or more sites. Nine AM fungal spore morphotypes belonging to Acaulospora, Funneliformis, Glomus, Gigaspora, and Sclerocystis were found to be associated with lycophytes and fernsItem ARBUSCULAR MYCORRHIZAL AND DARK SEPTATE ENDOPHYTE FUNGAL ASSOCIATIONS IN FERNS AND LYCOPHYTES OF PALNI HILLS, WESTERN GHATS, SOUTHERN INDIA(Brazilian Journal of Botany, 2014) Muthukumar T; Sathiyaraj G; Priyadharsini P; Uma E; Sathiyadash KWWe assessed the arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal associations in 57 ferns and 3 lycophytes (belonging to 15 families in 39 genera) of different life forms (epiphytic, saxicolous and terricolous) occurring in Palni Hills of Western Ghats. Fungal symbiosis was absent in all the three lycophytes examined. Fifty-five of the 57 ferns (91.66 %) examined had AM and 37 (64.91 %) had DSE fungal association. This is the first report on AM and DSE fungal association for 22 and 30 species, respectively. In addition, AM morphology was evaluated for the first time in 34 species. Sixty-five percentage of the mycorrhizal ferns had intermediate- type AM and 19.30 % had typical Paris-type AM morphology. Both Paris- and intermediate-type AM morphologies were observed in 10.53 % of ferns. The root length colonized by AM and DSE fungal structures significantly varied among species, and a significant negative relation existed between the root length colonized by AM and DSE fungi.Item INVITRO ASYMBIOTIC SEED GERMINATION, MYCORRHIZATION AND SEEDLING DEVELOPMENT OF ACAMPAE PRAEMORSA (ROXB.) BLATT. & MC CANN, A COMMON SOUTH INDIAN ORCHID(Asian Pacific Journal of Reproduction, 2013-06-20) Sathiyadash K; Muthukumar T; Bala Murugan S; Sathishkumar R; Uma E; Jaison S; Priyadharsini PObjective: To develope a conservation strategies for orchid species. Methods: Seeds of Acampae praemorsa (Roxb.) Blatt. Mc Cann (A. praemorsa) were obtained from mature pods collected from Velliangiri hills and germinated on Murashige and Skoog (MS) medium supplemented with various concentration of Benzylaminopurine (BAP). Results: Maximum seed germination (85%) was observed on MS media supplemented with 2 mg/L BAP. Seed germination percentage increased with increasing concentrations of BAP (0.5 mg/L to 2 mg/L), but 3 mg/L of BAP inhibited seed germination. Variations observed were significantly (P<0.01) different for concentrations of growth regulators, days and their interactions. The embryos in the seeds swelled prior to germination. Fifty days after inoculation, well developed greenish porotocorm like bodies (PLBs) were formed and by 80th day, 85% (maximum) of the PLBs were observed in MS supplemented with 2 mg/L BAP. Eighty days after seed sowing, the germination rate decreased and the PLBs were transformed into first and second leaf stages in media supplemented with Naphthaleneacetic acid (NAA). Maximum seedling numbers (84%) were observed in MS medium supplemented with 1 mg/L NAA at 110th day. After 110 days, the seedlings were transferred to 0.6 g/L MS medium containing activated charcoal and similar concentration of growth regulators for root induction. After rooting, the seedlings were transferred to ex vitro conditions. Conclusions: In present study all the mycorrhizal seedlings survived, because orchid mycorrhizal fungi enhance growth of orchid plantlets and present study gives an effective protocol for seed germination and plantlet regeneration from immature seeds which can be used for establishing A. praemorsa populations in Velliangiri Hills and elsewhere.Item TREE SPECIES AS HOSTS FOR ARBUSCULAR MYCORRHIZAL AND DARK SEPTATE ENDOPHYTE FUNGI(Journal of Forestry Research, 2012) Uma E; Sathiyadash K; Loganathan J; Muthukumar TA survey of 35 tree species (belonging to 28 genera in 19 families) in Aliyar, South India was carried out to ascertain their arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal status. All the tree species examined had AM association. AM and DSE colonization is reported for the first time in 20 and 14 species respectively. Cooccurrence of AM and DSE was observed in 14 (40%) tree species. The extent of DSE colonization was inversely related to the extent of AM fungal colonization. Six tree species had Arum-type, 18 had intermediate type and 11 had typical Paris-type AM morphology. AM fungal spore morphotypes belonging to 11 species in two genera were isolated from the rhizosphere soil. AM fungal spore numbers were not related to the extent of AM colonization and Glomus dominated spore diversity. AM association individually and along with DSE were found respectively in the 63% and 44% of the economically important tree species. The occurrence of AM and DSE fungal association in economically important indigenous tree species indicates the possibility of exploiting this association in future conservation programmes of these species.Item MORPHOLOGY, ANATOMY AND MYCORRHIZAE IN SUBTERRANEAN PARTS OF ZEUXINE GRACILIS (ORCHIDACEAE)(Anales de Biología, 2011-12-14) Muthukumar T; Uma E; Karthikeyan A; Sathiyadash K; Sarah Jaison; Priyadharsini P; Ishworani C; Muniappan VZeuxine gracilis (Berda) Bl., is an endemic, terrestrial green orchid whose morphology, anatomy and mycorrhizal status is unknown. So we investigated: (a) root and rhizome anatomy; (b) root hair characteristics and mycorrhizal colonization patterns in Z. gracilis plants collected from Western Ghats region of southern India. The prominent anatomical characters in the roots were: absence of velamen, spiranthosomes, and the presence of single layered exodermis and nine arched protoxylem. The rhizome had an uniseriate epidermis, abundant spiranthosomes in the inner cortical cells, a distinct endodermis with casparian strips and biseriate vascular bundles. The presence of fungi both in the roots and rhizomes was revealed. The entry of fungi was chiefly through root hairs and through epidermis in the rhizome. Fungi formed pelotons and monilioid cells in the root cortex. Additionally, arbuscular mycorrhizal (AM) fungi characterized by the presence of aseptate hyphae, vesicles and spores were present occasionally in roots. The lack of arbuscules in Z. gracilis indicated the AM to be non functionalItem ARBUSCULAR MYCORRHIZAL AND DARK SEPTATE ENDOPHYTE FUNGAL ASSOCIATIONS IN SOUTH INDIAN GRASSES(Symbiosis, 2010-10-21) Sathiyadash K; Muthukumar T; Uma EWe examined arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) fungal association in 50 south Indian grasses from four different sites. AM fungal diversity was also compared among the different sites. Forty-four of the 50 grasses examined had AM association and dual association with DSE fungi occurred in 25 grasses. We report for the first time AM and DSE fungal status in 23 and 27 grasses respectively. Arum-type AM morphology was the dominant occurring in 21 grasses with typical Paris-type colonization occurring in 6 grasses. AM morphology is reported for the first time in 35 grasses. Over the different sites, spore density in the soil ranged from 5–22 per 100 g air-dried soil. Spores of 11 AM fungal taxa were isolated from the soil samples of grasses of which nine belonged to Glomus, one to Acaulospora and one to Scutellospora. No significant relationship existed between AM fungal colonization and spore numbers. Species richness was high in site II and Glomus aggregatum, Glomus viscosum and Glomus mosseae were most frequent species at different sites. Overall species diversity indices (Simpson index, Shannon-Weaver index, species equitability index) differed significantly between sites