Southern Western Ghats Of India Research Articles

Medicinal plants of the Western ghats as possible inhibitors of oxidation in various biological lipid substrates

Medicinal plants are nature’s fighters against several degenerative diseases. The reverse pharmacological approach focuses on traditional knowledge on the usage of medicinal plants for various diseases and revalidating the effect using modern techniques. The Western ghats of Southern India has sheltered a wide range of medicinal plants. The objective of this research work was to evaluate the oxidation inhibiting ability of aqueous extract of four medicinal plants from the Western ghats, namely; Andrographis paniculata (Burm.f.) Wall. ex Nees, Costus speciosus (Koen.) Sm., Canthium parviflorum Lam. and Abrus precatorius L. in biological lipid substrates, viz., cholesterol, low-density lipoprotein and brain homogenate. The IC50 values of the plant extracts were calculated and the correlation between the phytochemicals and the antioxidant effect exhibited was studied. From the results, it was observed that, the inhibition of oxidation by the aqueous extract of all the four medicinal plants, followed the order cholesterol >LDL> brain homogenate. C. parviflorum exhibited highest antioxidant activity in cholesterol (94.8%) and brain (37.35%) than compared to other medicinal plants. In LDL, the highest antioxidant activity (73.75%) was exhibited by C. speciosus. The antioxidant activity of CP and CS in the substrates correlated well with the polyphenol and flavonoid content of the extracts. The IC50 values of CS in cholesterol (305 μg, r2 = 0.9972) was the least among all the medicinal plants. The overall protective action in the substrates was higher in C. parviflorum than other medicinal plants. Thus, the selected medicinal plants can be further explored for its biological activity and utilized as sources of natural antioxidants and phytochemicals against various oxidative stress related diseases.

Fires in Seasonally Dry Tropical Forest: Testing the Varying Constraints Hypothesis across a Regional Rainfall Gradient.

The “varying constraints hypothesis” of fire in natural ecosystems postulates that the extent of fire in an ecosystem would differ according to the relative contribution of fuel load and fuel moisture available, factors that vary globally along a spatial gradient of climatic conditions. We examined if the globally widespread seasonally dry tropical forests (SDTFs) can be placed as a single entity in this framework by analyzing environmental influences on fire extent in a structurally diverse SDTF landscape in the Western Ghats of southern India, representative of similar forests in monsoonal south and southeast Asia. We used logistic regression to model fire extent with factors that represent fuel load and fuel moisture at two levels—the overall landscape and within four defined moisture regimes (between 700 and1700 mm yr-1)—using a dataset of area burnt and seasonal rainfall from 1990 to 2010. The landscape scale model showed that the extent of fire in a given year within this SDTF is dependent on the combined interaction of seasonal rainfall and extent burnt the previous year. Within individual moisture regimes the relative contribution of these factors to the annual extent burnt varied—early dry season rainfall (i.e., fuel moisture) was the predominant factor in the wettest regime, while wet season rainfall (i.e., fuel load) had a large influence on fire extent in the driest regime. Thus, the diverse structural vegetation types associated with SDTFs across a wide range of rainfall regimes would have to be examined at finer regional or local scales to understand the specific environmental drivers of fire. Our results could be extended to investigating fire-climate relationships in STDFs of monsoonal Asia.

Implication of PKS type I gene and chromatographic strategy for the biodiscovery of antimicrobial polyketide metabolites from endosymbiotic Nocardiopsis prasina CLA68.

Advanced approach in probing for polyketide antimicrobials requires novel genomics and chromatographic strategies. An endophytic strain CLA68 was isolated from the root of Combretum latifolium Blume (Combretaceae) collected from the Western Ghats of Southern India. Strain CLA68 was then identified as Nocardiopsis prasina by its characteristic culture morphology and analysis of 16S rRNA gene sequence. Biosynthetic polyketide synthase genes were investigated using two pairs of degenerate primers. Ethyl acetate extract of CLA68 exhibited broad spectrum activity against a panel of test human pathogens. PKS type-I gene detection and chromatographic strategy yielded a robust polyketide antimicrobial compound which identified as nocapyrone E. Minimum inhibitory concentration of the purified compound against MRSA and other human pathogens ranged between 25 and 100μg/ml. The present work highlights the utility of N. prasina CLA68 as potential source for antimicrobial polyketide nocapyrone E which could help to combat multidrug-resistant pathogens. This study demonstrates feasibility of PKS type-I gene-based molecular approach and chemical investigation by chromatographic approach is the best method for prediction and rapid discovery of novel polyketides from endosymbiotic actinomycetes. The sequence data of this endosymbiotic actinomycete is deposited in GenBank under the accession no. KP269077.

Comparative Phytochemical Profiling and Quantification of Mangiferin Content in Species of Salacia from Southern Western Ghats of India

Many species of the genus Salacia L. are used in traditional Indian systems of medicines for their anti-diabetic potential. In this study, we carried out a comparative phytochemical evaluation of the roots of nine species of Salacia viz. S. agasthiamalana, S. beddomei, S. brunoniana, S. chinensis, S. fruticosa, S. gambleana, S. malabarica, S.oblonga and S. wayanadica, which are distributed in the Southern Western Ghats. Qualitative profiling showed the presence of different phytochemicals. Subsequently quantification of mangiferin, the prominent anti-diabetic molecule was carried out using HPLC in all these species. S. brunoniana (2.586 mg/g of dry root) showed maximum mangiferin content, followed by S. beddomei (2.195), S. chinensis (1.57), S. fruticosa (1.055), S. oblonga (0.305), S. agasthiamalana (0.086), S. malabarica (0.0296), S. gambleana (0.0218) and S. wayanadica (0.0005). The presence of mangiferin in S. agasthiamalana, S. beddomei, S. brunoniana, S. gambleana, S. malabarica and S. wayanadica, are reported for the first time. The study identified that S. brunoniana and S. beddomei could be the most promising raw material for anti-diabetic drug formulations based on mangiferin content.

Conservation implications of wildlife utilization by indigenous communities in the southern Western Ghats of India

Wildlife utilization in the tropics is massive, with nearly 5 million tons of bushmeat consumed by local communities. In India, a megadiversity nation, hunting—although illegal—is widespread among indigenous communities. However, the extent, frequency, and rationale for hunting, and factors influencing wildlife utilization are poorly known. Our study, based on 19 different indigenous communities in the Western Ghats region, revealed the utilization of 54 wild species/taxa. Although freshwater fish, herpetofauna, and small mammals were most frequently utilized, enforcement by the Forest Department was largely focused on large mammals. Gender, land ownership, number of domestic meats consumed, distance to markets, time spent hunting, and distance to hunting areas were major factors that affected wild meat utilization in the region. Although conservation needs to be focused on the most utilized groups, increasing access to domestic meats at remote settlements and integrating utilization of common, culturally prominent species can improve conservation of threatened fauna.

Two new taxa of Impatiens L. (Balsaminaceae) from Western Ghats of India

Two new taxa of Impatiens (Balsaminaceae), viz., I. sasidharanii sp. nov. and I. sasidharanii var. hirsuta var. nov. are described and illustrated from the southern Western Ghats of India. Detailed notes on description, ecology, distribution, morphological variations and IUCN status are provided along with illustrations.

Antimicrobial properties of endophytic actinomycetes isolated from Combretum latifolium Blume, a medicinal shrub from Western Ghats of India

Endophytic actinomycetes were isolated from Combretum latifolium Blume (Combretaceae),Western Ghats of Southern India and identified by its characteristic culture morphology and molecular analysis of 16S rRNA gene sequences. In this survey of endophytic actinomycetes, a total of 117 isolates representing 9 different genera of endophytic actinomycetes were obtained using four different isolation media and several of them seemed to be novel taxa. Streptomyces genera (35%) was the most frequently isolated strains, followed by Nocordiopsis (17%) and Micromonospora (13%). ISP-4 medium recovered more isolates (47%) when compared to rest of the media used. Preliminary antibacterial activity of the isolates was carried out by confrontation test. Ethyl acetate fraction of selected isolates in disc diffusion assay exhibited broad spectrum antimicrobial activity against test human pathogens. All Streptomyces spp. strains displayed significant antimicrobial activity against test pathogens. Strain CLA-66 and CLA-68 which are Nocordipsis spp. inhibited both bacterial and fungal pathogens where as other isolates inhibited atleast three test human pathogens in disc diffusion assay. Antimicrobial screening of endophytic actinomycetes from this host may represent a unique potential niche for antimicrobial compounds of industrial and pharmaceutical applications. This work is the first comprehensive report on incidence of potential endophytic actinomycetes inhabiting C. latifolium Blume.

Black Pepper Leaf Oil Mass Spectrometric Profile Variations in the Southern Western Ghats of India

nigrum leaves were collected from five locations from Kerala within a radius of 150 km, altitudinal variance of 1000m and annual rainfall variance of 1400mm. The extracted Piper nigrum leaf oil was profiled using a GC-MS, Beta Caryophyllene was the only constituent that was present in all the five locations, of which the highest concentration was noted in the high altitude region of Idukki. Micro-climate plays a vital role in the production of these constituents, as samples from the low range areas of Idukki and high range areas of Idukki did not have similar oil profiles. High amounts of Alpha Pinene were present in the sample from the low range region of Idukki whereas in the sample from the high range region of Idukki showed extremely high concentrations of Elemol. There is also great variation in concentrations of chemicals like Beta Gurjunene, Copaene and Germacrene D. This shows that the variance of micro-climate and micro- environmental factors like soil plays a significant role in the concentrations of certain phytochemicals in the Piper nigrum leaf volatile oil profile. Black pepper has recently been geographically indicated (GI tagged). The variations found in the leaf oil profile of the piper nigrum could help in reducing the abuse of the GI system.

Salvia misella (Lamiaceae)—A new record for Asia from the southern Western Ghats of India

The mint family, Lamiaceae is generally regarded as being one of the most highly derived plant families from the viewpoint of floral structures (Hedge 1992). The family is best known for their essential oils common to many members of the family and are a major source of culinary herbs. Within the subfamily Nepetoideae tribe Mentheae, the subtribe Salviineae includes 8 genera with about 954 species in the world (Harley et al. 2004). The genus Salvia L. (1753: 23) alone account for over 900 species in the subtribe and is the largest genera in Labiatae (Mabberley 2008). It is a tropical and subtropical genus mostly found in montane areas with the major diversity in Mediterranean, Central Asia, the highlands of Mexico and the Andes in South America (Rodrigues-Hahn et al. 1992).

Molecular profiling and antimicrobial potential of endophytic Gliomastix polychroma CLB32 inhabiting Combretum latifolium Blume

Fungal endophytes as a source of bioactive metabolites have led to the development of pharmaceutical products finding new applications. In a survey of endophytic fungal biodiversity, an antimicrobial endophytic strain CLB32 was isolated from the leaf of Combretum latifolium Blume (Combretaceae) from the Western Ghats of Southern India. CLB32 was then identified as Gliomastix polychroma (KR704576) by morphological and phylogenetic analysis based on internal transcribed spacer (ITS) nuclear rDNA and intervening 5.8S rRNA gene. CLB32 here constituted the first report on incidence of endophytic fungi from C. latifolium Blume. Ethyl acetate fraction of strain CLB32 was evaluated for antimicrobial activity by disc diffusion assay. Secondary metabolites produced effectively inhibited methicillin-resistant Staphylococcus aureus (18.33 ± 0.33 mm), Pseudomonas aeruginosa (14.66 ± 0.33 mm) and Candida albicans (14.00 ± 0.57 mm). Biosynthesis of these antimicrobial compounds was detected by analytical TLC-bioautography method as depicted by zone of inhibition on intensive the band. These findings suggest that G. polychroma CLB32, as a producer of natural antimicrobial drugs, could help to combat against multidrug-resistant infections and also provide baseline information for industrial applications.

Evaluating Generic Pantropical Allometric Models for the Estimation of Above-Ground Biomass in the Teak Plantations of Southern Western Ghats, India

The use of suitable tree biomass allometric equations is crucial for making precise and non- destructive estimation of carbon storage and biomass energy values. The aim of this research was to evaluate the accuracy of the most commonly used pantropical allometric models and site-specific models to estimate the above-ground biomass (AGB) in different aged teak plantations of Southern Western Ghats of India. For this purpose, the AGB data measured for 70 trees with diameter >10 cm from different aged teak plantations in Kerala part of Southern Western Ghats following destructive procedure was used. The results show that site specific models based on a single predictor variable diameter at breast height (dbh), though simple, may grossly increase the uncertainty across sites. Hence, a generic model encompassing dbh, height and wood specific gravity with sufficient calibration taking into account different forest types is advised for the tropical forest systems. The study also suggests that the commonly used pantropical models should be evaluated for different ecosystems prior to their application at national or regional scales.

Topographic and Bioclimatic Determinants of the Occurrence of Forest and Grassland in Tropical Montane Forest-Grassland Mosaics of the Western Ghats, India.

The objective of this analysis was to identify topographic and bioclimatic factors that predict occurrence of forest and grassland patches within tropical montane forest-grassland mosaics. We further investigated whether interactions between topography and bioclimate are important in determining vegetation pattern, and assessed the role of spatial scale in determining the relative importance of specific topographic features. Finally, we assessed the role of elevation in determining the relative importance of diverse explanatory factors. The study area consists of the central and southern regions of the Western Ghats of Southern India, a global biodiversity hotspot. Random forests were used to assess prediction accuracy and predictor importance. Conditional inference classification trees were used to interpret predictor effects and examine potential interactions between predictors. GLMs were used to confirm predictor importance and assess the strength of interaction terms. Overall, topographic and bioclimatic predictors classified vegetation pattern with approximately 70% accuracy. Prediction accuracy was higher for grassland than forest, and for mosaics at higher elevations. Elevation was the most important predictor, with mosaics above 2000m dominated largely by grassland. Relative topographic position measured at a local scale (within a 300m neighbourhood) was another important predictor of vegetation pattern. In high elevation mosaics, northness and concave land surface curvature were important predictors of forest occurrence. Important bioclimatic predictors were: dry quarter precipitation, annual temperature range and the interaction between the two. The results indicate complex interactions between topography and bioclimate and among topographic variables. Elevation and topography have a strong influence on vegetation pattern in these mosaics. There were marked regional differences in the roles of various topographic and bioclimatic predictors across the range of study mosaics, indicating that the same pattern of grass and forest seems to be generated by different sets of mechanisms across the region, depending on spatial scale and elevation.

A new record of Potamanthellus caenoides Ulmer 1939 (Ephemeroptera: Neoephemereidae) from the southern Western Ghats of India.

BackgroundAs part of ongoing exploration of the mayflies of hill streams of the southern Western Ghats of India, we establish a new record of mayfly.New informationPotamanthellus caenoides Ulmer 1939 is newly recorded based on larval collection from the upstream of Silent Valley National Park of the southern Western Ghats. Brief ecological notes are appended.

Does size matter? Comparative population genetics of two butterflies with different wingspans

The dispersal ability of a species is central to its biology, affecting other processes like local adaptation, population and community dynamics, and genetic structure. Among the intrinsic, species-specific factors that affect dispersal ability in butterflies, wingspan was recently shown to explain a high amount of variance in dispersal ability. In this study, a comparative approach was adopted to test whether a difference in wingspan translates into a difference in population genetic structure. Two closely related butterfly species from subfamily Satyrinae, family Nymphalidae, which are similar with respect to all traits that affect dispersal ability except for wingspan, were studied. Melanitis leda (wingspan 60–80 mm) and Ypthima baldus (wingspan 30–40 mm) were collected from the same areas along the Western Ghats of southern India. Amplified fragment length polymorphisms were used to test whether the species with a higher wingspan (M. leda) exhibited a more homogenous population genetic structure, as compared to a species with a shorter wingspan (Y. baldus). In all analyses, Y. baldus exhibited greater degree of population genetic structuring. This study is one of the few adopting a comparative approach to establish the relationship between traits that affect dispersal ability and population genetic structure.

An updated review of the genus Martensopoda Jäger, 2006 (Araneae: Sparassidae: Heteropodinae).

A new species of the huntsman spider genus Martensopoda Jäger, 2006, M. sanctor sp. nov., is described and illustrated from the southern Western Ghats of India. Detailed first description and illustration of the male of M. minuscula (Reimoser, 1934) with a redescription and illustration of its female are provided. The female of M. transversa Jäger, 2006 is redescribed and illustrated. An identification key and a distribution map of all three Martensopoda species are presented.

Stridulation and Courtship Behaviour of Four Endemic Pill-Millipedes, Arthrosphaera spp. (Sphaerotheriida: Arthrosphaeridae) of the Western Ghats of India

Mating behaviour of four species of pill-millipedes under genus Arthrosphaera Pocock (Arthrosphaera dalyi Pocock and Arthrosphaera disticta Pocock, Arthrosphaera fumosa Pocock and Arthrosphaera magna Attems) endemic to the Western Ghats of Southern India was analyzed in mesocosms. Stridulation is a classical communication signal in males as well as females for mate selection. Conglobation (or volvation) is a mechanism of defence to protect from disturbance or avoid predation. If male touches female or vice versa they conglobate. To avoid disparity among individuals of the same species, volvating pill-millipedes evolved stridulation behaviour for communication. The male broadcasts appropriate signal to female through stridulation to advertise its interest in mating. The females test the male’s fitness by conglobation and suitable male uncoils the partner through stridulation signals. Male with its pygidium successfully uncoils the female and attains suitable orientation for courtship. Male pairs with female ventro–ventro contact in opposite direction to deposit sperm into the vulva of female. The duration of mating varies from species to species and usually a lapse from 3 to 30 min. Vibration generated by stridulation is species-specific and its perception mechanism in pill-millipedes is yet to be clearly understood. Present study emphasized the structure of stridulatory organs, mechanism of stridulation and pattern of mating behaviour in four species of pill-millipedes.

Population Status of the Endangered Lion-Tailed MacaqueMacaca silenusin Kalakad-Mundanthurai Tiger Reserve, Western Ghats, India

The lion-tailed macaque, endemic to the evergreen forests of the Western Ghats in southern India, is endangered. Over the last two decades surveys have documented population declines in a number of areas. There still exists a huge gap, however, in our knowledge of this macaque's status at many sites. It is imperative to identify and conserve existing populations in contiguous, large and undisturbed forests. We present the results of a first complete population survey carried out in the Kalakad-Mundanthurai Tiger Reserve (KMTR) in the Agasthyamalai landscape; an area that has not been surveyed for two decades. We found a population of at least 462 lion-tailed macaques in 30 groups. The mean group size was 15.4 individuals per group, and the adult sex ratio was 3.5 females/male. The forest of the KMTR is connected with forest reserves in the states of Tamilnadu and Kerala, and it is probable that the lion-tailed macaque population of KMTR is likewise contiguous. Measures must be taken at a landscape level for the long-term conservation of the species; the status of the populations in the neighboring sites need to be assessed, and priority should be given to adequate protection for the Agasthyamalai sub-population as a whole.

Genetic and morphological variation in natural teak (Tectona grandis) populations of the Western Ghats in Southern India

Teak (Tectona grandis L.f.) is a popular hardwood species native to South and South-East Asia. The possible association of amplified fragment length polymorphism (AFLP) marker with morphological variables of eleven important characters viz. girth at breast height (GBH), height of tree, bole height, branch knots, presence of fluting, spiral stem, leaf hair, leaf length/breadth ratio, branching pattern, bark colour and petiole shape for nine natural populations comprising 180 genotypes of teak (9 populations × 20 trees). The phenogram constructed using Euclidean distances for the eleven morphological characters showed that the populations were not grouped according to their geographical origin. The Mantel’s test for pairwise correlation between Euclidean distances of different morphological variables and genetic distances from AFLP data revealed that only petiole character (r =0.269; p =0.046) and height of tree (r =0.200; p =0.001) were significantly correlated with that of AFLP data matrix. The nine populations in this study covered a geographic area of about 1000 km stretch along the Western Ghat of South India. A test of correlation between genetic and geographic distance matrices revealed a significant positive correlation (r =0.475; p =0.009). The lack of perfect congruence between morphological and molecular data except for geographic distance, tree height and petiole character suggested that the morphological system might be useful for the morphotypes management but not appropriate to study the genetic structure of the teak populations.

Corosolic acid content and SSR markers in Lagerstroemia speciosa (L.) Pers.: A comparative analysis among populations across the Southern Western Ghats of India

Lagerstroemia speciosa commonly known as ‘Banaba’ is native of south–east Asia which exhibits both horticultural and therapeutic value. The anti-diabetic and anti-obese property of the tree is attributed to corosolic acid (CRA)-a pentacyclic triterpene seen predominantly in the mature leaves. Although there are studies on either chemical or genetic variation in L. speciosa from different regions, none have dealt with their association to discuss the formation of chemical diversity. For the first time, we have analyzed CRA content in 12 natural populations corresponding to 42 samples seen in the Southern Western Ghats (SWG) using chromatography techniques and genetic variation estimated using SSR markers. Significant variation in percentage distribution of CRA ranging from 0.005% to 0.868% dr.wt. was recorded wherein populations from the north SWG contain relatively more active principle (mean=0.321%) than their counterparts in the south (mean=0.064%). Similarly, SSR data showing relatively high rate of gene flow (Nm=2.72) and low genetic differentiation (FST=0.14) is indicative that populations from north are genetically more diverse than those in the south (Nm=0.48; FST=0.38). The scatter plot derived by Principle Component Analysis (PCA) of chemical and genetic data shows similar pattern of clustering that reveals strong association between the two sets of data. It is concluded that the observed variation in CRA content in natural populations of the species depends more on the genetic background and less on edaphic factors.

Impact of forest fragment size on between-group encounters in lion-tailed macaques.

Between-group encounters are an obvious outcome of intergroup competition. Between-group encounters in primates range from avoidance to fatally aggressive. The prevailing hypotheses explain such encounters as mate defense strategy by males and resource defense strategy by females. However, the rate and nature of between-group encounters may also be influenced by habitat and demographic characteristics. We studied the effect of forest fragment size on group encounters in lion-tailed macaques in the Western Ghats of southern India. The encounter rate decreased as the fragment size increased. Group density and home range overlap correlated positively with the encounter rate. The aggressive encounters were more in the relatively medium-sized fragment where the observed frequency of between-group encounters was higher than the expected frequency than in the small fragment and the large forest complex. Together, these results indicate a complex pattern of effects of fragment size on between-group encounters in primates.