How to Identify Rare and Endangered Ferns and Fern Allies

Identification of rare and endangered plant species is the first requirement for any conservation programme. The IUCN guideline is the only available method to identify the rare and endangered species and it requires vast data on the wild population of the target species. None of the biological characters, which are playing main role in the survival and distribution of several species, is used in IUCN guideline. In the meantime there are several difficulties in following IUCN guideline, particularly the non availability of complete field data. Moreover, the same guideline can not be used for all the groups of species in equal importance. The vascular cryptogams, pteridophytes, are also an important component of any mountainous flora and they have also to be conserved in nature. As they are the primitive vascular plants on the earth, they are getting depleted in the flora due to various reasons and it is the right time to identify the rare and endangered pteridophytes to conserve them. By considering various difficulties of IUCN method for the identification rare and endangered pteridophytes, a very simple method has been adopted by using just four criteria and this method can be applied to Pteridophytes from any region of the world

Isozyme Analysis on Different Varieties of Sugarcane

Isozymic and protein diversity among five sugarcane varieties viz., Co 6304, Co 85019, Co 8371, Co 89003 and Co 91010 were studied to understand the varietal interrelationship and to identify the biochemical marker for the disease resistance and stress tolerance. The standard technique of vertical gel electrophoresis PAGE was employed for size separation of isozymes. The gel was stained with different staining solutions for different isozyme systems viz. peroxidase, esterase, acid phosphatase, alkaline phosphatase and proteins. Rf values of the banding profiles, similarity index and variation between the varieties were analysed. Among the four enzyme systems, peroxidase profile reveals the difference between the disease resistant / susceptible and abiotic stress tolerant / non tolerant varieties. The two isoperoxidase bands with Rf values 0.62 and 0.66 showed their presence in disease resistant and abiotic tolerant varieties. The presence of two marker bands (0.62, 0.66) of resistant and stress tolerant varieties suggest that the variety Co 6304 may also be resistant to smut, wilt and moderately resistant to red rot and tolerant to drought

Effect of Heavy metal stress on spore germination of Pteris confusa T. G. Walker and Pteris argyraea T. Moore

Background: Plants have both constitutive and adaptive mechanisms for coping with the elevated metal concentrations and they are utilized to clean the polluted soil and water. Unlike angiosperms hyperaccumulators, fern hyperaccumulators are equipped with inherent biological characteristics that could be exploited in the phytoremediation strategies aimed at decontaminating polluted sites. Fern spores can be successfully used to screen the hyperaccumualting ferns and also to test the toxicity of the metal contaminated samples. Purpose of the Study: In the present study, a preliminary attempt was made to compare the tolerance capacity of the spores of two ferns; Pteris confusa T. G. Walker and Pteris argyraea T. Moore against the heavy metal zinc (Zinc sulphate). Spores of the two ferns were cultured in Knop’s liquid medium with various concentrations of zinc sulphate (0-200ppm). Results: In the case of P. confusa normal germination was observed in control, 120 ppm and 140 ppm and the germination of spores were failed in 160, 180 and 200 ppm of zinc supplemented cultures. In contrary, P. argyraea showed maximum percentage of spore germination in 140 ppm zinc supplemented cultures and the control and 120 ppm zinc sulphate supplemented cultures were failed to show the germination. The germination percentage and growth rate was decreased in high concentration of zinc sulphate. Rhizoids are showed more tolerance to heavy metal than protonema of P. argyraea. Conclusion: Difference in response of spores to the heavy metal zinc may be due the difference in the hyper-accumulating capacity of the ferns

Preliminary Phytochemical and Anti-Bacterial Studies on \u3cem\u3ePassiflora edulis\u3c/em\u3e

Preliminary phytochemical and antibacterial activity of the leaf and callus of Passiflora edulis Sims, were examined using extracts of benzene, methanol, ethanol, isopropanol, chloroform and petroleum ether. Of these, chloroform extract of the leaf and callus showed the maximum solubility and antimicrobial activity with the MIC ranging from 100 to 250 µl. Extracts of benzene, petroleum ether and isopropanol were ineffective in inhibiting the selected bacteria. In addition, this phytochemical study confirmed the presence of alkaloids, saponins, tannins and triterpenes from ethanol and chloroform extracted sources

Quantifying the local density of optical states of nanorods by fluorescence lifetime imaging

In this paper, we demonstrate a facile far-field approach to quantify the near-field local density of optical states (LDOS) of a nanorod using CdTe quantum dot (QD) emitters tethered to the surface of the nanorods as beacons for optical readouts. The radiative decay rate was extracted to quantify the LDOS; our analysis indicates that the LDOS of the nanorod enhances both the radiative and nonradiative decay of QDs, particularly the radiative decay of QDs at the end of a nanorod is enhanced by 1.17 times greater than that at the waist, while the nonradiative decay was enhanced uniformly over the nanorod. To the best of our knowledge, our effort constitutes the first to map the LDOS of a nanostructure via the far-field method, to provide clarity on the interaction mechanism between emitters and the nanostructure, and to be potentially employed in the LDOS mapping of high-throughput nanostructures

Apogamous Isoetes coromandelina L.f. (Isoetaceae) with asynaptic meiosis

This cytological study on Isoetes coromandelina L.f (Isoetaceae) from Tirunelveli District, Tamil Nadu, South India shows the presence of twenty two individual chromosomes along with a fragment (n=2n=22+1) during meiosis in megaspore mother cells without the presence of any bivalent. Cytomixis between two megaspores is very common, resulting in the formation of a high percentage of abortive spores. The present material is of an apogamous taxon with asynaptic Meiosis as reported by Abraham and Ninan from Kerala and Karnataka

Pharmacognostical Studies on Three Asplenium Species

The present study was aimed to study the pharmacongonstical characters viz., morphological and physico-chemical characteristics of three rare medicinally important spleenworts viz. Asplenium affine Swartz, Asplenium decrescens Kunze and Asplenium zenkeranum Kunze. The present study revealed the presence of alkaloids, triterpenes, and flavonoids in Asplenium species. Based on the Thin Layer chromatogram, interspecific relationship was assessed. A. affine and A. decrescens showed 42% of similarity coefficient and A. zenkeranum was varied from A. affine and A. decrescens with 36% variance

Indication for the Presence of Mixed Modes of Sporogenesis in Lindsaea Heterophylladryand. (Lindsaeaceae: Pteridophyta)

Morphological studies on sporangia and spores of the hybrid fern Lindsaea heterophylla Dryand. (L. ensifolia Sw. x L. bonii Christ.) from South India indicates the presence of mixed mode of sporogenesis with the occurrence of 8 spored sporangia during peak winter (December) and 32 spored sporangia during late winter (January). This kind of reproductive flexibility in this fern is attributed to environmental adaptation. Both morphological and reproductive flexibility in this species also proved the hybrid origin of this species. Further cytogenetical studies are required on this hybrid fern along with its parents to confirm the ploidy level of this fern, Lindsaea heterophylla Dryand.</jats:p