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Azadirachta indica (neem) is a multipurpose tree species that is distributed in Asian and African countries. It is used in food, medicine and agriculture. Our study used 20 neem-specific polymorphic simple sequence repeat (SSR) markers to investigate the genetic diversity among 170 neem germplasm from three distinct populations [North Central (NC), West Central, and South Eastern (SE)]. The study revealed moderate levels of genetic diversity. The SE population exhibited the highest genetic variation, as indicated by the observed heterozygosity (Ho = 0.63) and expected heterozygosity (He = 0.64) values, while the NC population showed the lowest genetic diversity. Furthermore, evidence of inbreeding was exhibited by the overall positive value of the fixation index (F = 0.13). The polymorphic Information content value 0.583 indicates a moderate level of marker diversity within the populations. The significant genetic differentiation coefficient (Fst) was 0.25. Analysis of molecular variance revealed that 12% of the total genetic variation was observed among the populations, whereas 88% was found within populations. Principal component analysis, clustering, and structure analysis were in correspondence with each other and identified three populations of A. indica with slight admixtures. The results of this study provide a genetic diversity of the A. indica germplasm for harnessing its genetic potential and conservation.

This study was conducted on 79 harvested poplar trees of eight-years-old planted at five spacing geometries (5 × 4 m, 10 × 2 m, 18 × 2 × 2 m, North–South and East–West boundary) to construct component-wise dry biomass (above + below ground) equations for estimating biomass & carbon sequestered. The complete data were randomly divided into two mutually exclusive and independent sets viz estimation-set (80%) to fit the model and validation-set (20%) to ascertain accuracy of the fitted model. DBH was found to be the most appropriate independent variate to construct best-fit biomass equations with growth attributes. Among various attempted functions (linear, allometric, logistic, Gompertz, Chapman and exponential), allometric function i.e., Total Biomass = 0.2575*DBH (2.191)  (R 2 Adj  = 0.97, RMS = 925.71 and AIC = 427.87) was found to be the best-fit. The total dry biomass production of poplar varied from 69.90 to 207.98 Mg ha −1 in aboveground and 13.46 to 36.69 Mg ha −1 in belowground in five planting geometries. Total carbon storage (above + below ground) under various spacings viz 5 × 4 m, 10 × 2 m, 18 × 2 × 2 m, North–South and East–West boundary poplar were 112.48, 101.80, 84.87, 77.28 and 38.84 Mg C ha −1 , respectively. The carbon sequestration rate was observed to be higher in 5 × 4 m (14.09 Mg C ha −1  yr −1 ) closely followed by 10 × 2 m (12.61 Mg C ha −1  yr −1 ), 18 × 2 × 2 m (10.50 Mg C ha −1  yr −1 ),E–West (9.56 Mg C ha −1  yr −1 ) and North–South plantation (4.80 Mg C ha −1  yr −1 ). Keeping in view, regionally derived allometric equations contribute to limiting the uncertainty in the estimation of biomass and carbon sequestration, which may be helpful to monitoring, reporting and verification (MRV) needs in carbon management policies.

For the estimation of genetic diversity and population structure, 23 accessions of Leucaena leucocephala were characterized using morphological and molecular markers. A medium to high degree of genetic variability was calculated among these accessions based on eight quantitative traits. Furthermore, a cluster analysis based on morphological characteristics grouped the 23 Leucaena accessions into five groups based on their similarities. Furthermore, the principal component analysis revealed that eight quantitative traits contributed for 82.57% of the total variability. Eleven simple sequence repeats (SSR) markers showed a high degree of polymorphism among the 23 L. leucocephala accessions. The polymorphic information contents (PIC) for these 11 markers were estimated and revealed that SSR723 had higher PIC value (0.90). Also, the dendrogram generated based on 11 markers distinctively demarcated most of the L. leucocephala accessions into different clusters indicating its vast genetic diversity in the population. A population structure study of these 23 L. leucocephala accessions showed the existence of two gene pools. Also, analysis of molecular variance showed that there was 13% variability between populations, while there was 87% variability within the population. The first and second coordinates of principal coordinate analysis unconditionally distributed these accessions into four coordinates based on their similarity. Overall, the high degree of genetic variability described by morphological and molecular markers in L. leucocephala can be used as a basic tool for assessing genetic diversity and linkage mapping in Leucaena genetic improvement programs.

Metal matrix composites (MMCs) are the next generation materials, globally popular for having numerous potential applications in aircraft, automobile and biomedical industry. Magnesium being continuously replacing other conventional materials however it is a hard to process material. Recently, friction stir processing (FSP) is drawing attention among researchers to fabricate MMCs. Using FSP, superior properties of magnesium based MMCs being successfully achieved. The primary aim of this paper is to review and provide a thorough summary of FSP synthesized magnesium based composites. Additionally the effect of secondary phase particles on the tribological behavior of produced composite materials is also summed up. Mechanical along with microstructural properties produced from stirred process and contribution of strengthening mechanism is addressed, as well.

Dragon fruit is an important fruit crop in the Cactaceae family and is known for its high nutraceutical properties, greater monetary returns, low maintenance and stress resistance. Three of its species viz. Hylocereus undatus, H. megalanthus, and H. polyrhizus are extensively grown in the world. Improved agronomic practices have been important for obtaining quality yield. Available literature highlights the novel production techniques such as pruning, training, use of plant hormones, and other horticultural techniques. Nonetheless, there is dearth of complete and comprehensive information about production technology of dragon fruit. This paper reviews all available information related to production technology that would be useful for researchers and farmers.

Background Pongamia is considered an important biofuel species worldwide. Drought stress in the early growth stages of Pongamia influences negatively on the germination and seedling development. Due to lack of cultivar stability under drought stress conditions, establishment of successful plantation in drought hit areas becomes a major problem. To address this issue, drought stress response of four Pongamia genotypes was studied at morphological, physio-chemical and transcriptome levels. Methods and results Drought stress was levied by limiting water for 15 days on three months old seedlings of four genotypes. A significant effect of water stress was observed on the traits considered. The genotype NRCP25 exhibited superior morpho-physiological, biochemical drought responses. Also, the genotype had higher root length, photosynthetic pigments, higher antioxidant enzymes and solute accumulation compared to other genotypes. In addition, transcript profiling of selected drought responsive candidate genes such as trehalose phosphate synthase 1 (TPS1), abscisic acid responsive elements-binding protein 2 (ABF2-2), heat shock protein 17 (HSP 17 kDa), tonoplast intrinsic protein 1 (TIP 1–2), zinc finger homeodomain protein 2 (ZFP 2), and xyloglucan endotransglucolase 13 (XET 13) showed only up-regulation in NRCP25. Further, the transcriptome responses are in line with key physio-chemical responses exhibited by NRCP25 for drought tolerance. Conclusions As of now, there are no systematic studies on Pongamia drought stress tolerance; therefore this study offers a comprehensive understanding of whole plant drought stress responsiveness of Pongamia. Moreover, the results support important putative trait indices with potential candidate genes for drought tolerance improvement of Pongamia.

Tree-based systems in arid region of India are an integral part of livelihood and environment security. Traditionally, the maintenance of scattered trees on farm to reap several tangible and intangible benefits is a way of life. Presently, these systems are often known as low-hanging fruit and become a key weapon to fight climate change evil by offsetting greenhouse gas (GHG) emission through carbon sequestration. Therefore, to quantify the offsetting potential of GHG emission and area occupied by these tree-based systems in Rajasthan was undertaken. The study was carried out into two major aspects: estimation of agroforestry area using satellite remote sensing data, and to estimate the carbon sequestration potential of existing agroforestry by using dynamic CO2FIXv3.1 model for a simulation period of 30-years in five districts (20% sampling), namely, Bikaner, Dausa, Jhunjhunu, Pali and Sikar from Rajasthan, India. The estimated area under agroforestry in Rajasthan was 1.49 million ha. The findings revealed that the major tree species existing on farmer’s field were Prosopis cineraria, Tecomella undulata , Capparis decidua, Acacia tortilis , Prosopis juliflora , Azadirachta indica and Ziziphus mauritiana with an observed number of trees in selected districts varied from 1.40 to 14.90 ha −1 (with average tree density of 9.71 ha −1 ). The total biomass (tree + Crop) varied from 2.22 to 19.19 Mg ha −1 , whereas the total biomass carbon ranged from 1.00 to 8.64 Mg C ha −1 . The soil organic carbon ranged from 4.51 to 16.50 Mg C ha −1 . The average estimated carbon sequestration and mitigation potential of the agroforestry were 0.26 Mg C ha −1  year −1 and 0.95 Mg CO 2 eq ha −1  year −1 on farmers' field of Rajasthan. At the state level, the reduction of GHG emission potential of agroforestry was found to be 1.42 million tonnes annually, which helps to cut carbon footprint and achieve targets of Paris agreement.

Various agroforestry systems are prevalent in different agro-climatic regions of India and occupy sizeable area. Populus deltoides (poplar) based agroforestry systems are very predominant in Indo-Gangetic Plains of northern India. These systems are not only meeting wood demand of wood-based industries but also contributing significantly in generating employment, reducing atmospheric CO2 vis-à-vis mitigating climate change. The present study aimed at estimating area under poplar plantations and assessment of biomass production and carbon stock at district level for selected districts of Punjab and Haryana states. High resolution multispectral remote sensing data (LISS-IV, spatial resolution- 5.8 m) have been used for mapping poplar area in these districts. Growth data (tree density, diameter at breast height) from farmers’ fields were collected for assessment of aboveground and total biomass. Poplar area in Hoshiarpur, Rupnagar, Ludhiana, Shahid Bhagat Singh Nagar, Yamunanagar, Kurukshetra and Karnal districts accounted for 3.19, 4.09, 1.02, 0.43, 7.25, 1.58 and 0.97%, respectively, of their geographical area. As percentage of agroforestry area, poplar area occupied 43.8% in four districts of Punjab and 53.4% in three districts of Haryana. Estimated carbon stock in total biomass of poplar plantations was 0.931, 0.481, 0.287, 0.040, 0.949, 0.256 and 0.229 million tonnes, respectively. CO2 equivalent C in aboveground and total biomass was estimated to be 7.854 and 9.946 million t, respectively, in all these seven districts. The proposed methodology based on object-oriented image classification showed promising results as far as mapping of agroforestry systems/species is concerned.

India ranks fourth in terms of greenhouse gas (GHG) emissions and accounts for 6% of total GHG emissions in the world. Carbon dioxide ( CO 2 ) has major contribution of 76% in total GHG emissions. Agroforestry that integrates trees in the agricultural landscape is regarded as a strategy for both adaptation and mitigation of climate change. Agroforestry plays an important role in reducing the level of GHG emissions vis-à-vis atmospheric CO 2 through carbon sequestration. Carbon sequestration is the process involved in carbon capture and the long period storage of atmospheric CO 2 . In the present study, firstly area under agroforestry was estimated in Central Plateau and Hill region (agro-climatic zone-8) using satellite remote sensing data. Secondly, dynamic CO 2 FIX model v3.1 was used to assess the baseline total carbon and carbon sequestration potential (CSP) of agroforestry systems for a simulation period of 30 yr. Finally, equivalent CO 2 absorption was assessed with the help of estimated agroforestry area and net CSP in the zone. Estimated area in Central Plateau and Hill region is about 1.96 million ha, which is 5.18% of total geographical area of this zone. Total carbon sequestered at zone level was estimated to be 17.81 Tg (tera gram) C and equivalent CO 2 absorption is at 65.36 Tg. The CSP of agroforestry systems would be about 158.55 Tg C for a simulated period of 30 yr or CSP would be 5.28 Tg C yr - 1 at country level. On the other hand, equivalent CO 2 absorption was 586.50 Tg for a period of 30 yr or would be 19.55 Tg yr - 1 at country level. Hence, the present study concludes that agroforestry has significant contribution in reduction of atmospheric CO 2 which would have much more if the area under agroforestry and/or number of trees ha - 1 on farmlands are increased.

Tectona grandis L. (teak) is one of the cherished heritage tropical hardwood species that belongs to the Lamiaceae family. It is a large deciduous tree native to India, Myanmar and Thailand. The natural populations of teak remain an important source from the economic, ecological and environmental perspectives. Teak timber is well known for its quality in terms of durability and market value. It is naturally resistant to various biotic stress components due to the presence of tectoquinone, lapachol and deoxy lapachol; however, it takes a minimum of 20–25 years for the production of marketable wood to fetch high returns. This long haul provides sufficient time for pests and diseases to feast upon teak at various growth stages starting from nursery to timber mills which leads to a downturn in timber production. To meet the rising demand from wood industries, it is essential to manage the health of the teak plantation outside forests. The reports of new pests and diseases on teak escalated since 2010, especially from countries like Brazil and Mexico where we witness recent rise in commercial teak forests, and this vulnerability emphasizes the deployment of protection measures right from the supply of quality planting material. The update on the biotic factors comprising insect pests, fungal and bacterial infections, which are currently limiting teak wood production, will supplement the efforts involved in quality planting material production. Identification of plus trees with genetic resistance, molecular characterization and monitoring of pests and diseases on teak harnessing the recent developments in plant protection, along with the research on development of the package of practices for teak nurseries and plantation management, will only sustain teak production in near future.