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Assessing haplotypic and genotypic diversity is crucial for comprehending biological invasion dynamics and devising effective management strategies. In India, Gambusia spp. were introduced in the early twentieth century for mosquito biocontrol, but recent studies have demonstrated their detrimental impact on native biota. The present research employs molecular tools to investigate the haplotypic and genotypic diversity of Gambusia species in India. The findings reveal a greater distribution of Gambusia holbrooki and a lesser occurrence of Gambusia affinis in India. The study underscores that G. holbrooki was initially brought into India from Europe and later multiple times from other regions across the globe. Our global haplotypic network shows the presence of a single G. affinis haplotype, which is narrowly distributed in the northeastern part of India. Additionally, our population genetic analyses exhibit a low genetic variability and significant population genetic structuring among G. holbrooki populations. This study emphasizes the significance of evaluating haplotypic and genotypic diversity to develop a comprehensive understanding of the invasion history and dynamics of introduced species, thereby aiding in the development of effective management strategies that mitigate their negative impact on native biota.

Saraca asoca, commonly known as ‘Asoka’ or 'Ashoka,' holds significant medicinal value in India. However, due to the escalating demand in the herbal market, the species has suffered a severe decline in naturally occurring populations, primarily caused by the unregulated extraction of its wood. Particularly within the Western Ghats, a global biodiversity hotspot, the species faces critically low population sizes. The study addresses a highly relevant conservation concern, focusing on an ecologically and culturally important species within a global biodiversity hotspot. Twelve populations in the Western Ghats were analyzed using five highly polymorphic and newly developed microsatellite markers. The results revealed a total of 78 alleles, with an average of 15.6 alleles per locus across the twelve populations. The AMOVA analysis indicated that the species exhibits higher diversity within populations (91.38% variation) compared to the variation observed among populations (8.62%). Further analysis employing Bayesian clustering identified six distinct genetic clusters within Saraca asoca . Based on these genetic findings, strategies for the development of an in-situ conservation plan for the species have been formulated. Overall, this study sheds light on the genetic characteristics of Saraca asoca populations in the Western Ghats and provides valuable insights for the implementation of effective conservation measures.

Endophytes, both of bacterial and fungal origin, are ubiquitously present in all plants. While their origin and evolution are enigmatic, there is burgeoning literature on their role in promoting growth and stress responses in their hosts. We demonstrate that a salt-tolerant endophyte isolated from salt-adapted Pokkali rice, a Fusarium sp ., colonizes the salt-sensitive rice variety IR-64, promotes its growth under salt stress and confers salinity stress tolerance to its host. Physiological parameters, such as assimilation rate and chlorophyll stability index were higher in the colonized plants. Comparative transcriptome analysis revealed 1348 up-regulated and 1078 down-regulated genes in plants colonized by the endophyte. Analysis of the regulated genes by MapMan and interaction network programs showed that they are involved in both abiotic and biotic stress tolerance, and code for proteins involved in signal perception (leucine-rich repeat proteins, receptor-like kinases) and transduction (Ca 2+ and calmodulin-binding proteins), transcription factors, secondary metabolism and oxidative stress scavenging. For nine genes, the data were validated by qPCR analysis in both roots and shoots. Taken together, these results show that salt-adapted Pokkali rice varieties are powerful sources for the identification of novel endophytes, which can be used to confer salinity tolerance to agriculturally important, but salt-sensitive rice varieties.

Use of chemical fertilization and pesticides not only harm the environment but also have detrimental consequences on human health. In recent years, there has been a major emphasis worldwide on natural agriculture methods. Regenerative agriculture is known across the world as a combination of nature-friendly farming practices such as no-till, cover cropping, crop-rotation, agroforestry and use of organic home-based/farm-based ingredients to revive soil health. In India, a number of farmers are slowly adopting these practices using home-based mixtures and farmyard manure for soil rejuvenation and pest management. In order to evaluate the efficacy of the regenerative agriculture practices, this study compared conventional and regenerative agriculture plots for their soil bacterial and nutrient profiles. Two crops - ragi (Finger millet, an old world cereal eaten in India) and vegetable (tomato/beans), and different lengths (≤3 and >5 years) of regenerative practices were additional metrics considered to understand variabilities due to crop-type and period of application. The common regenerative agriculture practices used by farmers in this study included a mix of practices such as mulching, minimal-till, inter-cropping, crop-rotation, along with application of farmyard manure and other home-based concoctions rich in nutrients and microbes for enriching the soil. We found that all regenerative practices were effective in bringing about an enrichment for soil bacteria with a more heterogeneous composition. Additionally, in regenerative vegetable (RV) versus conventional vegetable (CV) and barren land (BL) plots the relative percentage abundance of Actinobacteriota (RV-7.47%/ CV-6.24%/BL -7.02%) and Chloroflexi (RV-9.37%/ CV-6.63%/BL-8.75%) was slightly higher. In contrast, levels of Acidobacteriota (RV-8.1%/ CV-9.88%/BL-9.62%) was significantly lower. Similarly, regenerative ragi (RR) in comparison with conventional ragi (CR) and barren land (BL) plots saw higher representation of Firmicutes (RR-5.45%/ CR-2.38%/BL-1.45%) and Actinobacteriota (RR-11.53%/ CR-7.08%/BL-7.15%) and a concurrent reduction in Acidobacteriota (RR-6.91%/CR-7.39%/ BL-9.79%). The RV plots were found to be enriched for Plant Growth Promoting Rhizobacteria (PGPRs) - sp. (RV-0.51%/CV-0.01%/BL-0.21%), and RR plots were enriched for sp. (RR-1.35%/CR-0.95%/BL-0.61%), and sp. (0.30%/0.12%/0.21%), which are known to play significant roles in vegetable and ragi growth respectively. Interestingly, long-term regenerative agriculture was able to support good nutrient composition while enhancing Soil Organic Carbon (SOC) levels. In all, the regenerative agriculture practices were found to be effective in improving bacterial community structure and simultaneously improving soil health. We found that BL soil with eucalyptus plantation showed among the least bacterial diversity suggesting detrimental impact on soil health.

Aim Climate change has a strong impact on species ranges and the genetic structure of populations, yet conclusions are often subject to large uncertainties when both are analysed independently. Here, we develop a novel framework to directly integrate population genetics and dynamic species distribution modelling to reduce such uncertainties when reconstructing the post‐glacial history of black pepper. Location Western Ghats, India. Methods Genetic data of 243 individuals from 14 populations of wild Piper nigrum were derived from six chloroplast and five nuclear DNA simple sequence repeats (SSRs). Dynamic species distribution models (DSDMs) were applied since the Last Glacial Maximum (LGM, 21,000 years BP) based on paleo‐climatic suitability at a high resolution (1 km, 100 years) and evaluated for a wide range of estimated migration rates and climate niches of the species. Population genetics and DSDMs were finally combined in a genetically informed DSDM, in which the estimated model parameters were optimised by maximising the correlation between the genetic diversity of the populations and their simulated colonisation history since the LGM. Results We observed higher gene diversity, haplotype richness, and allelic richness at lower latitudes, and two major phylogeographic groups belonging to the southern and central Western Ghats. Demographic inference from chloroplast SSRs estimated the split of these groups around the LGM. DSDMs showed a high uncertainty in parameter estimates, which were clearly reduced for the genetically informed DSDM. With this model, the correlation between genetic diversity and colonisation time was stronger than the correlation with latitude, and the simulation showed a northward expansion from low‐latitude refugia and a recent fragmentation of the species range. Main Conclusions Our integrative approach reduces uncertainty in DSDMs and facilitates the interpretation of the population genetic structure. This added value is not given when population genetics and species distribution modelling are applied independently and merely compared.

Invasive alien species have become the second major threat to biodiversity affecting all three major ecosystems (terrestrial, marine, and freshwater). Increasing drivers such as habitat destruction, expanding horticulture and aquaculture industries, and global pet and food trade have created pathways for exotic species to be introduced leading to severe impacts on recipient ecosystems. Although relatively less studied than terrestrial ecosystems, freshwater ecosystems are highly susceptible to biological invasions. In India, there has been a noticeable increase in the introduction of alien fish species in freshwater environments. In the current study, we aimed to understand how climate change can affect the dynamics of the biological invasion of invasive alien fishes in India. We also evaluated the river-linking project’s impact on the homogenization of biota in Indian freshwater bodies. We used species occurrence records with selected environmental variables to assess vulnerable locations for current and future biological invasion using species distribution models. Our study has identified and mapped the vulnerable regions to invasion in India. Our research indicates that the interlinking of rivers connects susceptible regions housing endangered fish species with invasive hotspots. Invasive alien fishes from the source basin may invade vulnerable basins and compete with the native species. Based on the results, we discuss some of the key areas for the management of these invasive alien species in the freshwater ecosystems.

A new cryptic species of bush frog Raorchestes honnametti sp. nov. is described from the south-eastern part of the Western Ghats, India. This newly described species belongs to the Charius clade and is morphologically similar to other clade members--R. charius and R. griet. Therefore, an integrative taxonomic approach based on molecular and bioacoustic analysis along with morphology was used to delimit the new species. Raorchestes honnametti sp. nov., is currently known only from Biligiri Rangaswamy Temple Tiger Reserve, a part of Biligiri Rangaswamy horst mountain range (a mountain formed due movement of two faults) formed during the Late Quaternary period (1.8-2.58 Ma). Discovery of cryptic species from a highly speciose and well-studied genus Raorchestes hints at the possible existence of several more cryptic species in this genus. We discuss the possible reasons for crypsis and emphasize the need for continued systematic surveys of amphibians across the Western Ghats.

Myristica swamps are tree-covered wetlands within the evergreen forests of the Western Ghats, India. Even with their little-known biota, the swamps are virtually a live museum that is of great interest to biologists. The swamps harbour several rare-relic floristic and faunal taxa, comprising many endemic and threatened species. Most of the plant species in the swamp are highly restricted in their distribution and have several structural and physiological modifications. These swamps are one of the most unique and primeval ecosystems of the Western Ghats. They once formed a large hydrological network all along the Western Ghats, but due to increased human pressure, these now exist as small, isolated pockets and are one of the most threatened ecosystems in India. The presumed widespread loss of Myristica swamps and other perennial freshwater swamps calls for intensive research on the ecosystem services provided by these swamps, their landscape value and the function they play in watershed dynamics. Swamps are primarily drained for areca gardens and paddy fields. The swamps of the Western Ghats are threatened with extinction, yet scientists know little about them. Studies on flora and faunal diversity of these swamps exist, but the research gaps are notable when it comes to the hydrology, soil studies, and ecosystem services provided by these swamps. Further research is needed on these three topics in order to provide a comprehensive understanding of the abiotic factors governing swamps and to formulate a rationale for their preservation. There is also a lack of research on the potential impacts of climate change and population growth on these swamps. This review highlights the importance of these freshwater swamps, their ecology and prior research on them, and focuses on the need for conservation initiatives to save the last few swamps.

The center of diversity of Piper nigrum L. (Black Pepper), one of the highly valued spice crops is reported to be from India. Black pepper is naturally distributed in India in the Western Ghats biodiversity hotspot and is the only known existing source of its wild germplasm in the world. We used ecological niche models to predict the potential distribution of wild P. nigrum in the present and two future climate change scenarios viz (A1B) and (A2A) for the year 2080. Three topographic and nine uncorrelated bioclim variables were used to develop the niche models. The environmental variables influencing the distribution of wild P. nigrum across different climate change scenarios were identified. We also assessed the direction and magnitude of the niche centroid shift and the change in niche breadth to estimate the impact of projected climate change on the distribution of P. nigrum . The study shows a niche centroid shift in the future climate scenarios. Both the projected future climate scenarios predicted a reduction in the habitat of P. nigrum in Southern Western Ghats, which harbors many wild accessions of P. nigrum . Our results highlight the impact of future climate change on P. nigrum and provide useful information for designing sound germplasm conservation strategies for P. nigrum .

In recent years, there has been a rather acrimonious debate on matters concerning the biology of invasive species, some as fundamental as the definition and what constitutes an invasive species. However, an abiding commonality of all invasive species is the fact that they have all moved away from their native ranges to newer and often non-native ranges. In plants, Lantana camara has shifted from its native South American range distribution to most other parts of the world. In animals, the African giant snail has dispersed from Africa to most parts of Asia. What do such niche shifts signify about the nature and quality of the habitats to which the invasive species have moved? In this paper, using the classical niche paradigm, we analyse if niche shifts of thirty-three of the world’s top invasive species constitute just moving from one habitat to another similar habitat somewhere on the earth (home away from home) or that they have moved to totally new habitats (different from their native home). Surprisingly, our results show that for 90% of the world’s top invasive species, movements have been largely restricted to homes away from home, rather than into alien homes. This clearly indicates the potential inertia that species might face in moving out of their fundamental niche. We discuss these results in the context of the overall debate on invasion biology and how niche conservatism may have played a role in dampening the rates of invasion.