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Thamnocalamus spathiflorus is a shrubby woody bamboo invigorating at the alpine and sub-alpine region of the northwestern Himalayas. The present investigation was conducted to map the potential distribution of Th. spathiflorus in the western Himalayas for current and future climate scenario using Ecological Niche Modelling (ENM). In total, 125 geo-coordinates were collected for the species presence from Himachal Pradesh (HP) and Uttarakhand (UK) states of India and modelled to predict the current distribution using the Maximum Entropy (MaxEnt) model, along with 13 bioclimatic variables selected after multi-collinearity test. Model output was supported with a significant value of the Area Under the "Receiver Operating Characteristics" Curve (AUC = 0.975 ± 0.019), and other confusion matrix-derived accuracy measures. The variables, namely precipitation seasonality (Bio 15), precipitation (Prec), annual temperature range (Bio 7), and altitude (Alt) showed highest level of percentage contribution (72.2%) and permutation importance (60.9%) in predicting the habitat suitability of Th. spathiflorus. The actual (1 km2 buffer zone) and predicted estimates of species cover were ~136 km2 and ~982 km2, respectively. The predicted range was extended from Chamba (HP) in the north to Pithoragarh (UK) in southeast, which further protracted to Nepal. Furthermore, the distribution modelling under future climate change scenarios (RCP 8.5) for year 2050 and 2070 showed an eastern centroidal shift with slight decline of the species area by ~16 km2 and ~46 km2, respectively. This investigation employed the Model for Interdisciplinary Research on Climate (MIROC6)–shared socio-economics pathways (SSP245) for cross-validation purposes. The model was used to determine the habitat suitability and potential distribution of Th. spathiflorus in relation to the current distribution and RCP 8.5 future scenarios for the years 2021–2040 and 2061–2080, respectively. It showed a significant decline in the distribution area of the species between year 2030 and 2070. Overall, this is the pioneer study revealing the eco-distribution prediction modelling of this important high-altitude bamboo species. [ABSTRACT FROM AUTHOR]

The introduction of exotics is common in forestry, and majorly important species, like eucalypts, poplar, and Casuarina sp. occupy vast areas in the Indian subcontinent. Importantly, with the latest cost-effective sequencing techniques, genetic diversity research through molecular marker approaches on major exotics provides novel information for genetic improvement in economic traits with climatic adaptation. The study was carried out on Grevillea robusta to assess genetic relatedness and diversity among 228 genotypes belonging to five northwestern states in India. These genotypes were assayed using twelve simple sequence repeat (SSR) markers. A population structure analysis using structure software identified four major gene pool subgroups with clear-cut differences from each other. Principal coordinate analysis also supports the clustering patterns of the unweighted pair group method with arithmetic mean analysis. In the case of genetic diversity assessment, a total of seventy-three alleles were detected from twelve SSRs, with an average of 6.08 ± 0.71 per locus. Polymorphism information content ranged from 0.17 to 0.67 with a mean of 0.44 ± 0.045, indicating high levels of polymorphism across the genotypes. All the evaluated SSRs demonstrated moderate genetic diversity (observed heterozygosity = 0.31 ± 0.03; expected heterozygosity = 0.32 ± 0.03; and genetic differentiation = 0.295) among the sampled genotypes. These findings indicate significant genetic variability in the germplasm to warrant selection and have potential for a long-term tree improvement program of G. robusta in India. Study Implications: The study on population genetics of Grevillea robusta in exotic environments assessed probable gene pools, provenances, and genetic diversity in geographical distribution range of the species in the Indian scenario. The basic population genetic measures revealed the high diversity areas and probable seed zones of G. robusta in its exotic range. Importantly, the study will be helpful in the selection of candidate plus trees of G. robusta to further strengthen the genotype × environment interaction study for future breeding programs. Further, studying the genetic makeup for moderately diverse species offers valuable insights into evolutionary history, population dynamics, and ecological interactions, which may lead to conservation efforts and guidance for the management of trees such as G. robusta in their native and introduced regions. [ABSTRACT FROM AUTHOR]

In December 2022, a leaf spot and blight disease was observed in Eucalyptus plantations in northern India. Morphological features coupled with phylogenetic analysis of combined internal transcribed spacer (ITS), translation elongation factor 1‐alpha (tef1) and β‐tubulin (tub2) regions confirmed the association of Pseudoplagiostoma eucalypti with the disease symptoms. The pathogenicity of P. eucalypti was first proved on detached leaves of Eucalyptus camaldulensis and reconfirmed in glasshouse inoculation experiments. Finally, Koch's postulates were fulfilled by re‐isolating the pathogen from the inoculated leaves. This pathogen was first described in 1995 from the leaves of Eucalyptus spp. collected from southern India, and this study confirms its first serious occurrence after more than two decades in northern India. In addition, this is the first report on the polyphasic characterization of P. eucalypti from India. [ABSTRACT FROM AUTHOR]