Browsing by Author "Jaison S"

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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 P
To 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.
CHROMIUM ACCUMULATION IN PLANTS OF THERAPEUTIC VALUE GROWING NATURALLY ON TANNERY POLLUTANT CONTAMINATED AND NON-CONTAMINATED SOILS
(Springer- Biological Trace Element Research, 2016-05-25) Jaison S; Muthukumar T
Herbal preparations used to treat human ailments globally can be contaminated with various heavy metals (HMs) originating from the raw materials or from the manufacturing processes. Therefore, we assessed 22 medicinal plants growing naturally on tannery pollutant contaminated (Site-C) and non-contaminated (Site-NC) sites for their ability to accumulate chromium (Cr). The Cr contents in soil and various plant parts were estimated using an atomic absorption spectrophotometer. Translocation and bioconcentration factors were calculated. The soil at Site-C had 27-fold higher concentration of total Cr than at Site-NC. Chromium accumulation is reported for the first time in 50 % of the medicinal plants examined and varied significantly among the sites. Shoots of Ricinus communis and Amaranthus viridis had maximum concentrations of Cr at Site-C, whereas in Site-NC, none of the plants had Cr accumulation >30 ppm. Ricinus communis, Amaranthus viridis, and Amaranthus spinosus had translocation factor (TF) greater than the one in the Site-C and Lantana camara had TF >1 in Site-NC. The bioconcentration factor (BCF) was >1 only for Ricinus communis at both the sites. The majority of the medicinal plants at Site-NC had Cr content exceeding the permissible limit of 2 ppm suggested for herbal raw material. The results of the study clearly emphasize the need for screening plants of therapeutic value for the presence of HMs even when collected from non-contaminated soils. Moreover, proportional allocation of Cr in different plant parts provided an insight on the safety of these parts when specifically used in herbal preparations.
INFLUENCE OF ORGANIC POLLUTANTS ON ARBUSCULAR MYCORRHIZAL FUNGI
(Nova Science Publisher, 2010) Uma E; Jaison S; Muthukumar T
The numerous benefits contributed by arbuscular mycorrhizal (AM) fungi has lead to recognition of their benefits in sustainable agriculture and various natural environmental processes. Application of anthropogenic and other compounds intentionally in the form of pesticides, fungicides, fertilizers or unintentionally like polycyclic aromatic hydrocarbons (PAH) which affect soil fungi have shown varying effects on AM association. Not all organic pollutants are detrimental to AM fungi. Some fungicides such as Fludioxonil have a stimulatory effect on mycorrhizal formation and function. Rapid decrease in the metabolic activity of AM fungi, a decline in arbuscule production, which is the main site of nutrient exchange between the host plant and the fungus, reduction in the total root length colonized and slow colonization rates are the negative effects shown by certain fungicides. Pesticides generally inhibit AM colonization and spore numbers. Slow release mineral fertilizers though benefit AM fungi, their excessive use can result in suppression of the AM fungi. Certain PAH especially anthracene reduce the development of extra radical mycelium, sporulation, root colonization and spore germination. Different AM fungal species show differential sensitivity even within a particular class of organic pollutant. Caution should also be exercised while irrigating soils with effluents as these could affect AM fungi. A reduction in our dependency on conventional agricultural practices especially organic pesticides by using AM fungi as a biological tool which is possible only by maintaining low levels of organic pollutants in the soil. Minimal use of organic pollutants especially pesticides would enable the maintenance of a healthy AM fungal populations essential for sustainable plant production systems.
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 P
Objective: 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.
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 V
Zeuxine 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.
ROLE OF ARBUSCULAR MYCORRHIZAL FUNGI IN ALLEVIATION OF ACIDITY STRESS IN PLANT GROWTH
(Springer- NewYork, 2014) Muthukumar T; Priyadharsini P; Uma E; Jaison S; Pandey R R
Soil acidity is a major constraint for crop production worldwide as nearly half of the potential arable lands are acidic. Plant productivity in acid soils is limited by toxic levels of aluminum (Al), manganese (Mn), and iron (Fe) as well as deficiencies of plant available nutrients, especially phosphorus (P). Plants have developed several morphological, biochemical, and physiological adaptations against acidity stress. Among these, symbiosis with arbuscular mycorrhizal (AM) fungi is a strategy plants have evolved to survive and thrive in acid soils. The AM symbiosis increases plant growth in acid soils through enhanced uptake of nutrients. A reduction in Al and Mn phytotoxicities also occurs in response to AM symbiosis through a number of mechanisms such as binding of the toxic ions by the fungal hyphae, vesicles or auxiliary cells, exudation of organic acids, phosphatases, and production of glomalin. However, like plants, AM fungal species and ecotypes also vary to a great extent in their tolerance and ability to impart plant growth benefits in acid soils. It is, therefore, essential to identify suitable AM fungi that could confer tolerance and render maximum benefits to crops in acid soils.
ROLE OF ORGANIC AMENDMENTS ON ARBUSCULAR MYCORRHIZAL FORMATION AND FUNCTION
(Nova Science Publishers, 2011) Jaison S; Uma E; Muthukumar T
The last two decades have seen a renewed interest in organic farming and amelioration of soils affected by conventional agriculture. Different types of organic substances like farmyard manures, green manures, composts, sludges and effluents are added to the soil to enhance fertility. These organic amendments influence soil microbial populations and function. Arbuscular mycorrhizal (AM) fungi are an integral component of most agricultural and natural systems, and provide a range of benefit to the host plant. The prime benefit of AM fungi to plants include improved nutrition especially phosphorus (P) and nitrogen (N) in nutrient stressed soils. Other non-nutritional benefits include improved water relations, enhanced resistance to soil-borne pathogens, improved drought resistance, heavy metal tolerance and soil structure. As most crop and horticultural plants are mycorrhizal any factors that influence AM fungi affects plant growth and productivity. Organic amendments improve plant mycorrhization, AM fungal spore numbers and their diversity. However, certain organic sources rich in certain chemicals like phenols inhibit mycorrhization. The effect of organic amendments on AM fungi depends on the composition of the organic sources.
ZINC INFLUENCES REGENERATION OF TALINUM PORTULACIFOLIUM STEM CUTTINGS IN NUTRIENT SOLUTION
(AcademicPres- Notulae Scientia Biologicae, 2018-12-21) Muthukumar T; Jaison S; Dinesh Babu Selvam
Zinc (Zn) is an essential micronutrient for plant growth and development, but toxic at high concentrations. The present study focused to underline the direct effect of different concentrations (0-50 ppm) of Zn on the regeneration ability and morphological characteristics of Talinum portulacifolium stem cuttings in hydroponic solution over a period of 35 days without the interference of other soil factors. High concentrations of Zn (40-50 ppm) affected callusing, root initiation, root and shoot development to varying levels. At high concentrations, Zn caused stem decay, stunting and browning of roots, wilting, withering and necrotic spots on leaves. Increasing concentrations of Zn inversely affected the lateral shoot development, stem elongation, leaf, root numbers and total root length of the stem cuttings. Though Zn had no significant influence on fresh or dry weights of stem, low concentration (15 ppm) of Zn increased the fresh and dry weights of leaves by 11.17% and 26.79% respectively, compared to 0 ppm and with 77.06-243.80% and 47.92-255.00% compared with those raised in 20-50 ppm. Zn concentrations >10 ppm reduced the root fresh weight by 28.57-90.47% and dry weight by 27.27-90.91% than those at 0 ppm. The Zn content in leaves and stems increased linearly with increasing concentrations of Zn and ranged from 1.09-125.62 ppm and 1.00-110.26 in stems and leaves respectively. The tolerance index varied between 81 and 138 for different concentrations of Zn. The results of the study clearly indicate that high concentrations of Zn inhibit the regeneration of T. portulacifolium stem cuttings.