Optimizing in vitro micropropagation strategies in Santalum album L. through different explants

This study focuses on optimization of in vitro propagation protocols for Santalum album L. (Indian sandalwood) to address the increasing global demand and to aid in conservation aspects. This investigation evaluated various micropropagation parameters including explant types, basal media, disinfection methods and plant growth regulators (PGR). Murashige and Skoog medium consistently outperformed other media, with shoot tips showing the highest morphogenetic response (66.66%). Surface disinfection with 4% NaOCl for 10 min was the most effective and resulted in the explant survival rate of 86%. For shoot induction, 2 mg/L kinetin in MS medium resulted in the highest number of shoots (3.81) and longest shoots (5.39 cm) after 60 days. An effect was observed when PGR was combined with 5.0 mg/L kinetin + 2.0 mg/L BAP, corresponding to a shoot induction rate of 65.75%. Root induction was recorded at 14.79% after 10 days with the best treatment (MS + 1 mg/L IBA). Callus culture showed limited success as only one treatment (MS + 1 mg/L BAP + 25% coconut water) showed a regenerative response of 7.14%. These results provide a foundation for micropropagation of Sandal while highlighting areas that require further optimization, particularly in root induction and acclimation phases

Do calcareous soils affect morphological and physiological characteristics of maize hybrids and their iron efficiency?

Maize (Zea mays L.) is the third most cultivated cereal crop in the world after wheat and rice. Soil calcareousness is the key growth limiting factor causing a substantial decline in plant growth and yield in many arid and semiarid regions globally. This study aimed to understand the variability in morphological and physiological traits among maize hybrids as well as their iron (Fe) efficiency on calcareous soils. Five ruling maize hybrids [COH (M) 6, COH (M) 7, COH (M) 8, COH (M) 9 and COH (M) 10] and their six inbreds [UMI 1200, UMI 1201, UMI 1205, UMI 1210, UMI 1220, and UMI 1230] were evaluated on three calcareous soils having various free CaCO3 content (6.23 to 17.3%) with and without Fe supply. The experiment was carried out in the greenhouse of the Department of Soil Science, Tamil Nadu Agricultural University, Coimbatore, in 2019. Soil calcareousness reduced the morphological and photosynthetic parameters of all the maize hybrids, and the reduction was more in highly calcareous soils (17.3%). Significant variation in Fe efficiency among maize hybrids was observed and shows good association with physiological and photosynthetic characteristics. The maize hybrids COH (M) 6, COH (M) 8, and COH (M) 7 record higher growth attributes, photosynthetic parameters, and active Fe content with better Fe efficiency. Lower Fe efficiency was noted with inbreds UMI 1230 and UMI 1220. The study showed that maize hybrids and their inbreds were sensitive to higher soil calcareousness, but the magnitude of differences varied with genotypes

Genetic diversity, correlation and path analysis in female palmyrah (Borassus flabellifer L.) germplasm- a research article

In this study, 16 female germplasm of palmyrah were analysed to assess diversity among the accessions. The experiments were laid in Randomized Block Design with 2 replications. Around 27 characters were observed during the research, and they were subjected to correlation analysis, path analysis and genetic divergence. The results of the statistical analysis revealed the characters such as the number of leaves per tree, petiole length, number of inflorescences per tree, number of branches per inflorescence, number of fruit bunches per tree and number of fruits per bunch showed significant and positive correlations with fruit yield per tree. The path analysis showed, the traits viz., crown length (0.040), number of leaf segments per leaf (0.795), leaf length (0.845), inflorescence length (0.366), number of fruit bunches per tree (0.687), potassium (0.850), Total Soluble Solids (0.368), fruit length (0.230) and number of branches per inflorescence (0.170), petiole length (0.006), potassium content (0.850), phosphorous content (0.026) and calcium content (0.042) showed high positive direct effect with fruit yield per tree in female germplasm. In the genetic diversity analysis, the 16 germplasm were grouped into 12 clusters. The highest inter cluster distance was noticed between cluster VIII and cluster XI (959.377). The cluster VIII (Acc.11-KP-KKM) and cluster XI (Acc.2-OD -KKM) were showed high genetic divergence and utilized in the hybridization programme for developing superior genotypes with enhanced quality and improved yield. Among the various character studied, the maximum contribution to divergence was observed for zinc followed by number of fruits per bunch, fruit length, calcium and fruit weight

Climatic and edaphic influences on productivity and carbon sequestration of farm grown teak (Tectona grandis, linn.f) in Tamil Nadu, India

Teak (Tectona grandis, Linn.f) is one of the most sought-after tree crops due to the exceptional quality and high market value of its timber. Currently, the Indian subcontinent imports a significant quantity of teak to meet its growing demand. The growth and wood quality of teak are influenced by edaphic and climatic variations across sites, a factor that has been largely underexplored in research. The primary objective of the study is to analyse teak growth, wood quality, and carbon sequestration potential under farmland condition.  To address this, the study was conducted across three agroclimatic zones of Tamil Nadu: North Eastern Zone (NEZ), North Western Zone (NWZ), and Cauvery Delta Zone (CDZ), focusing specifically on farmland conditions. The analysis encompassed biometric attributes, volume, and carbon sequestration potential of farm-grown teak across different age classes. The findings of the study reveal that among the three agroclimatic zones, the NEZ (15-20 years age class) recorded the highest biometric attributes, including mid diameter (MD) (0.193 m), volume (0.379 m3), heartwood proportion (0.239 m3), and carbon sequestration (0.683 Mg/acre).. Based on the overall performance, trees in the 15-20 years age class exhibited superior heartwood formation under farmland conditions. Therefore, this age class is   recommended for teak cultivation in farmland conditions across Tamil Nadu to maximize growth, wood quality, and carbon sequestration potential

Nanobiosensors for early detection of plant pathogens

Plant pathogens are a major concern in production of crops as they lead to a great loss of food grains. Although several methods are available to manage the diseases and the chemical-based methods are frequently used, and sometimes indiscriminate use poses serious problems to the environment. It is, therefore, necessary to detect plant pathogens at an early stage in order to control epidemics. Plant pathogens can be detected using conventional methods such as culture-dependent, biochemical and molecular techniques; however, these methods need advanced technical skills and well-equipped laboratory facilities and are not suitable for in situ analysis. Several nanotechnology-based methods are available for plant pathogen detection. Among them, biosensing systems for early detection of the pathogen using nanobiosensor are gaining momentum in field of research on plant pathogen detection. Materials having size ranging from one and one hundred nanometers are known as nanoparticles. These materials have special qualities that can be used to improve agricultural practices. Nanobiosensors are novel integrated systems of biosensors that are made up of a bioreceptor, transducer and a detector on the nano scale size. These nano-inspired biosensors have played a major role in enhancing nature of life through different medical, environmental and quality-control applications globally. Numerous nanobiosensors have been developed, including those for detecting plant infections caused by fungi, viruses, and bacteria. This review will contribute to understanding the basics of biosensors and their accessible biosensor based detecting tools and techniques for plant pathogens

Elucidating the genetic variability and diversity among Chilli (Capsicum annuum L.) genotypes for growth and yield-related traits under sodic soil in Tamil Nadu through a multivariate approach

Chilli (Capsicum annum L.) is a commercially important crop cultivated for both vegetable and spice uses. This study aims to explore the genetic diversity of thirty genotypes under sodic soil conditions at HC&RI(W), Tiruchirappalli, over two seasons (Kharif and Rabi) in 2023-2024. Analysis of variance (ANOVA) revealed significant variability among the genotypes for thirteen different quantitative and qualitative parameters evaluated under sodicity. The phenotypic coefficient of variation was higher than the genotypic coefficient, suggesting minimal environmental influence on the traits. Most parameters exhibited high heritability, with several (e.g., number of days for first picking, seeds per pod and chlorophyll stability index) showing high genetic advance, indicating the potential for improvement through direct selection. Principal Component Analysis (PCA) reduced the genotypes to thirteen components, with the first four accounting for 73.24% of the variability. The genotypes are divided into five clusters based on the Euclidean distance through Mahalanobsis D2 analysis grouped the genotypes into five clusters, each cluster demonstrating superiority in specific traits suitable for further breeding. Notably, the high inter-cluster distance between clusters IV & V and III & V indicates diverse genetic material that could be valuable for hybridization programs aimed at improving sodic soil tolerance

Screening rice genotypes for nitrogen efficiency under graded nitrogen application

The global application of nitrogen (N) fertilizers continues to rise in efforts to bolster agricultural productivity. However, this surge in usage has led to significant N losses, resulting in low nitrogen use efficiency (NUE) among genotypes and consequent water and air pollution. Although many studies advocate reducing N fertilizer usage, research on screening rice genotypes under graded N application is limited. This study aimed to screen rice genotypes to identify N use efficient cultivars under varying nitrogen levels: N0, N50, N100 and N150. The study also sought to identify key physiological traits linked to grain yield under reduced N conditions. Grain yield decreased by 45.2 % at N0 and 21.4 % at N50 while increasing by 22.3 % at N150 compared to N100. Under reduced N application (N0 and N50), MTU-1010, Vasumati, DRR Dhan-58, Varadhan, Brown Gora SB 92, Tulasi, BV-1692 and DRRH2 exhibited least reduction in grain yield, over N100. Notably, parameters such as ?PSII (actual quantum yield of PSII), ETR (electron transport rate) and qP (coefficient of photochemical quenching) displayed a robust positive association with grain yield under reduced N application compared to the recommended (N100) and high (N150) N application. This underscores the significance of PSII photochemistry in enhancing grain production under limited N. Consequently, leaf chlorophyll fluorescence traits emerge as promising indicators for screening rice genotypes with enhanced NUE under limited N scenarios. In summary, the study conclusively identifies Varadhan as a genotype demonstrating high efficiency in nitrogen utilization, both in terms of grain yield and GYEI, particularly under reduced N regimes

Impact of land configuration methods on growth parameters of soybean in summer rice fallows

A field experiment was performed to examine the impact of land configuration methods on various growth attributes of soybeans in summer rice fallows at the Instructional Farm, Vellayani. The experiment was conducted from February to May 2023 in a split plot design with three main plot treatments, viz., broadbed and furrow (BBF) (l1), ridge and furrow (RAF) (l2), and flatbed method (l3), and six varieties, viz., JS 9305 (v1), KDS 726 (v2), JS 2069 (v3), AISB 50 (v4), JS 335 (v5), and Basara (v6) as subplot treatments, replicated four times. The growth attributes were significantly influenced by land configuration methods where BBF recorded taller plants (14.98, 29.31, 39.06, 45.83 cm), highest leaf count (2.57, 4.73, 9.30, 11.07), superior leaf area index (LAI) (0.502, 1.495, 2.077, 3.898), and higher nodule fresh weight (0.850 g). However, the variety JS 2069 recorded taller plants (15.55, 30.47, 40.38, 47.95, 52.66 cm), highest leaf count (0.78, 2.07, 4.03, 4.95, 6.22), higher number of branches per plant (and superior LAI (0.534, 1.810, 2.471, 4.284) at all growth stages. Among the varieties tested, AISB 50 produced a higher nodule count of 41.88 (on par with JS 2069) and the highest nodule fresh weight (0.863). The study identified the BBF method as the most effective land configuration method and JS 2069 as the most suitable variety for soybean cultivation in summer rice fallows of Kerala

Adapting cucurbits to diverse environments: Insights from GEI studies

Recently, there has been increasing concern about crop failures and yield gaps attributed to climate change, as certain genotypes fail to achieve the desired yields or quality due to variations in external temperatures. To address this issue, breeders are working to develop climate-resilient varieties by incorporating relevant genes into cultivars or genotypes or by utilizing desirable source plants in the breeding process. Additionally, management practices are being implemented to mitigate environmental impacts. Multi-environmental trials (METs) are commonly employed by breeders to assess the adaptability of specific genotypes or cultivars across different locations and time periods. The data collected from these trials is then analyzed using stability statistical models designed for stability analysis, which allows for the evaluation of cultivar or genotype performance under varied environmental conditions. Over the past six decades, there has been a significant focus on modeling genotype-environment interactions (GEI), leading to the development of various mathematical methods and models to decipher GEI in METs, often referred to as "stability analyses." In the era of omics, phenomics techniques have emerged as valuable tools for screening morphological and physiological variations in genotypes resulting from environmental factors. This review emphasizes the importance of GEI in cucurbits, highlighting how environmental stress can alter physiological traits such as stomatal conductance, single leaf area, rooting depth, and membrane composition. Furthermore, it notes the accumulation of stress-related proteins under stress conditions, underscoring the significance of understanding GEI for effective crop management and breeding programs

Assessing the relationship between hardseedness and seed morphometrics in Blackgram

Seed dormancy in black gram (Vigna mungo) was studied about seed size (weight, length, width) and their impact on hard seed formation and imbibition rate during the summer and Kharif seasons at NPRC, Vamban, Pudukkottai. The seeds of blackgram obtained during the summer season showed a significant negative correlation with hard seed occurrence (r = -0.639, P ? 0.01) and a positive correlation with imbibition rate (r = 0.451, P ? 0.05), Whereas seed width had a weaker negative correlation with hard seed occurrence (r = 0.357) and a positive correlation with imbibition rate (r = 0.273). In addition, the strongest correlation was found between hard seed occurrence and imbibition rate (r = 0.802, P ? 0.01). The seed length of the blackgram harvested during the kharif season had a stronger negative correlation with hard seed occurrence (r = -0.790, P ? 0.01) and a positive correlation with imbibition rate (r = 0.555, P ? 0.01). Seed width also showed significant correlations with hard seed occurrence (r = -0.673, P ? 0.01) and imbibition rate (r = 0.613, P ? 0.01). At the same time, the obtained seed weight correlations were generally weak. The results also proved a seasonal difference in the hard seedness of blackgram, which confirmed the occurrence of hard seed during the summer compared to the Kharif season. Thus, the study's findings highlight the importance of seed morphometrics and imbibition in predicting the presence of hard seeds in blackgram