Guava is the third richest source of ascorbic acid, an excellent antioxidant. Four guava genotypes namely, Lucknow-49, Shweta, Pant Prabhat, and Arka Kiran were studied concerning ascorbic acid accumulation at 35, 65, 95, and 115 days after fruit set during rainy and winter seasons. Two-way factorial Analysis of Variance (ANOVA) design with four genotypes as factor 1 and four stages as factor 2, was performed in four replications for the rainy and winter season at 5

Wheat grain filling is a major determinant of grain weight and yield, but its regulation under nitrogen (N) stress remains poorly understood. To investigate this, field and pot experiments were conducted under N-stress conditions using two contrasting wheat genotypes, Chotilerma (CL; small-seeded) and HB-208 (HB; bold-seeded). Although both genotypes showed similar reductions in nitrogen use efficiency (NUE) and grain yield under N stress, HB exhibited a greater decline in grain weight and grain volume, indicating poor grain-filling efficiency. Transcriptome analysis during the active grain-filling period (2–5 weeks after anthesis) revealed distinct molecular responses between the genotypes. Only 3

Tomato Leaf Curl New Delhi Virus (ToLCNDV), a bipartite begomovirus transmitted by whiteflies, is a major threat to cucumber (Cucumis sativus L.), a major vegetable crop. RNA-sequencing of samples collected at 0, 7, and 14 days after inoculation (DAI) with ToLCNDV virus, from resistant (DC-61) and susceptible (DC-773) genotypes, grown in the whitefly rearing facility, revealed 4022 differentially expressed genes (DEGs). More than 50% of the DEGs pertained to DC-773- 14 DAI. Defence-related pathways, including various transcription factors (TF), salicylic acid and jasmonic acid signalling, and secondary metabolite biosynthesis were found to be enriched among the DEGs. Integration of DEGs with known quantitative trait loci (QTLs) showed 13, 24, 12 and 7 DEGs on the QTLs of chromosomes 1, 2, 6 and 7, respectively. Of these, 9, 21, 8 and 6 DEGs were found to be differentially regulated between DC-61 and DC-773. DNA, amino acid, and cis-element variations of these DEGs, identified based on the resequencing data of DC-773 and DC-61, unravelled major candidate genes. CsLRR like protein kinase, serine/threonine-protein kinase SRK2E-like, CsGDSL esterase/lipase 1-like, CsWRKY51 and CsWRKY71 TF, CsWAT1-related protein, CsMYB TF and the DNA primase large subunit (CsPRiL) were the key candidate genes contributing to ToLCND resistance in cucumber. Eight InDel-based markers from the four QTL regions were designed and validated in the segregating population of DC-61/DC-773 by selective genotyping. This is the first study to integrate transcriptomic, genomic, and genetic data in cucumber, identifying chromosome 2 followed by chromosome 1 as the primary resistance hubs, providing markers and candidate genes for breeding of ToLCNDV-resistant varieties.

Five guava (Psidium guajava L.) genotypes, Punjab Pink, Hisar Surkha, Black guava, Shweta, and Pant Prabhat were studied for their pulp colour development at four stages: S1, when seed ball started developing colour; S2, when pulp started developing pink colour; S3, when uniform pink colour developed in pulp and seed ball; and S4, mature ripe. The two stages namely S2 and S3 in pink pulped guava genotypes had shown marked changes in pigment content and Hunter colour L*, a*, b* values. Hence, these stages are appropriate to study the expression of genes related to pulp colour. Out of three colour indices i.e., CI-1[1000 x a*/ (L* x b*)]; CI-2 [1000 x a*/ L*]; and CI-3 [1000 x b*/L*], the CI-2 had significantly higher correlation values for total anthocyanin (0.786) and lycopene (0.418) content. It also had higher correlation value for total carotenoid content (0.263) as compared to CI-1 and CI-3. The CI-2 values clearly distinguished between purple, pink and white pulped guava. Hence, it can be used for colour measurement and to decide the criteria for raw material (guava) selection for processing industry to develop safe products which are free from artificial colourants for consumers.

Guava (Psidiumguajava L.) is a widely cultivated tropical fruit crop valued for its nutritional richness, adaptability and economic importance. This study aimed to investigate the developmental progression of key fruit traits across eleven diverse guava genotypes during the winter season. Fruits were sampled at five growth stages, i.e. 35, 65, 75, 85 days after flowering (DAF) and at physiological maturity (PM) and were evaluated for fruit weight, length, width, seed core diameter and pulp thickness. Significant variation (p <= 0.05) was observed among genotypes and across stages for all traits, with the highest values occurring at the PM stage. Genotypes such as Sasni and VNR Bihi recorded the highest values for various fruit physical traits, making them good material for breeding programs focused on fruit size and pulp content. Principal Component Analysis (PCA) revealed that the first three components accounted for 79.46 % of the total variability among genotypes. PC1 (48.97 %) was primarily associated with fruit weight, diameter and seed core diameter at later stages. PC2 (16.15 %) reflected variation in pulp thickness and seed core diameter at mid stages, while PC3 (14.34 %) captured additional differences in fruit length andpulp thickness at maturity. This study provides insights into stage-wise fruit development, enabling future researchers to identify the most appropriate growth stages for recording key fruit traits. These insights will support precise phenotyping and strengthen selection decisions inguava breeding and improvement programs.

Tomato leaf curl New Delhi virus (ToLCNDV), a bipartite begomovirus transmitted by the whitefly (Bemisia tabaci), has emerged as a significant limiting factor in cucumber (Cucumis sativus L.) cultivation across tropical and subtropical regions. Despite its economic significance, the genetic and molecular determinants of resistance to ToLCNDV in cucumber remain largely unexplored. The present study employed a QTL-seq-based approach to unravel the genetic architecture of ToLCNDV resistance and identify candidate genomic regions associated with this complex trait. Whole-genome resequencing of resistant (DC 91) and susceptible (DC 773) parental lines, along with resistant and susceptible F₂ bulks, was performed using the Illumina HiSeq platform. High-quality reads were aligned to the C. sativus reference genome to identify genome-wide single-nucleotide polymorphisms (SNPs). Δ(SNP-index) analysis revealed a major quantitative trait locus (QTL) on chromosome 7 (Cy-2) conferring ToLCNDV resistance, spanning approximately 1.8 Mb of the genomic region. Three closely linked markers, SSR00931, one InDel (AMS12), and one CAPS marker (AMS13) were identified and developed for future marker-assisted selection (MAS). Expression profiling of genes within the QTL region via qRT-PCR revealed several putative candidate genes involved in defense signaling cascades, including those encoding leucine-rich repeat (LRR) receptor-like kinases, pathogenesis-related proteins, and enzymes associated with secondary metabolite biosynthesis. These genes are likely to contribute to viral restriction by modulating host defense pathways, suppressing virus replication, and reinforcing cellular barriers. The discovery of this major-effect QTL and closely linked markers provides a valuable genomic resource for precision breeding of ToLCNDV-resistant cucumber cultivars. The present study sheds light on the molecular basis of begomovirus-host interactions in cucurbits.

Guava (Psidium guajava L.) is popularly known as 'Super Fruit' and 'Apple of the Tropics' due to its nutritive richness. The pulp color of the guava fruit is associated with its pigment composition. In the present study, twenty-two guava hybrids and their 5 parental genotypes were evaluated for various fruit quality-related traits. The fruit weight (FW), fruit length (FL), fruit width (WF), pulp thickness (PT), seed core diameter (SCD) and FL/width ratio in guava hybrids varied from 78.93-207.10 g, 49.66-83.95 mm, 50.07-73.08 mm, 9.58-18.97 mm, 17.46-44.95 mm and 0.83-1.30, respectively. Total soluble solids (TSS), ascorbic acid (ASC) content, lycopene (LYC) content, total anthocyanins (TAN) and total carotenoids (TCR) in the hybrid fruits ranged from 10.17-18.80 oB, 143.79-275.99 mg/100 g, 0.17-9.51 mg 100 g-1, 0.01-4.61 mg 100 g-1and 0.16-2.49 mg 100 g-1, respectively. In general, white-pulped genotypes had higher ASC content than the pink/red pulped ones. Pulp-color-related traits, viz., LYC content, TCR and TAN, showed high heritability (H) and mean genetic advance (GA). Correlation analysis revealed that LYC content was positively correlated with TCR. The observed phenotypic coefficient of variation (PCV) for all traits exceeded the respective genotypic coefficient of variation (GCV), indicating genetic diversity among the studied guava genotypes. Cluster analysis differentiated guava genotypes into distinct clusters based on pulp color as well as other fruit-related traits. The hybrids, red/pink pulp: 'HSU/SH-16-8-2', 'HSU/SH-16-8-3', 'PPT/HSU-16-9-16' and white pulp: 'HSU/SH-16-8-18', 'SH/BG-14-1-2', excelled for fruit-related traits, having potential to be utilized in future breeding programs.

Wheat is a major staple food for 40 % of the world's population, accounting for around 20 % of total dietary energy and protein. However, in addition to providing nutrition, wheat contains several antinutritional factors. Wheat proteins, such as α-amylase/trypsin inhibitors (ATIs), have been known to cause allergic reactions, such as baker's asthma, and immunogenic reactions, such as non-celiac wheat sensitivity, and are key contributors to celiac disease in some predisposed individuals. Bread wheat varieties with no/reduced ATIs have not yet been developed. Here, 14 major ATI genes were targeted, and 12 were mutated using a tRNA-based multiplex CRISPR/Cas9 genome-editing system. The co-transformation of two DNA constructs, each carrying six sgRNAs, into immature wheat embryos was performed using the biolistic bombardment method. Gene-edited cv. Bobwhite wheat plant (T0) produced seeds with reduced ATI content (up to 30.6 %), resulting in α-amylase and trypsin inhibition activities reduced to 29.73 % and 21.38 %, respectively. Another variety of bread wheat, cv. HD2967 also showed a significant reduction in ATI content, as well as in α-amylase and trypsin inhibition activities. We expect gene-edited wheat plants with reduced ATI activity to be less immunogenic in humans; however, an immunogenicity study is essential.

The optimal utilization of nitrogenous fertilizer in agriculture is essential for reducing nitrogen (N) induced pollution and minimizing production costs. While studies have been conducted on the performance of rice genotypes under N-stresses, there remains a lack of detailed protocols for screening them during both seedling and maturity stages with absolute control of N, which is conveniently possible in hydroponics. Here, we report a detailed protocol for growing rice plants till maturity under N-stress (as well as N-optimum conditions) in the hydroponics system. This protocol provides comprehensive details on requirements, experimental setup, media, growing conditions, parameters to be observed, and management practices for the hydroponics system and troubleshooting. Apart from the growing condition, we also detail the procedures for recording the observations during the growth phase of the plants. Two contrasting rice genotypes for nitrogen use efficiency (NUE), IR64 (Indica rice) and Nagina 22 (Aus type rice), were grown under optimum as well as N-stressed conditions till the complete maturity of the plants for validation of this protocol. Significant differences (p < 0.05) between the two genotypes were observed on various parameters, including the morphological parameters and N uptake, from seedling to maturity stages. We also observed the effect of aeration in the hydroponics system for rice and found that non-aerated conditions were preferable. This comprehensive protocol offers an efficient, easy, low-cost, and low-maintenance system for hydroponic studies under N-stress conditions, enabling precise phenotyping and non-destructive examination of roots.

Chrysanthemum is a major flower crop grown globally for its use as cut flowers, potted plants and landscape decoration. It is highly susceptible to drought; hence, it is necessary to identify the drought responsive key traits in chrysanthemum. In this study, 14 standard chrysanthemum genotypes were evaluated for drought tolerance under hydroponics and pot culture in three replications of a completely randomised design (CRD). The seedlings were exposed to osmotic stress with 10% PEG (Polyethylene Glycol). In pot culture, a drought stress of -60 kPa was applied for seven days during the vegetative growth and flower bud initiation stages. R statistical analysis was performed (PCA analysis, R2.15.1 by R Development Core Team) to evaluate several morphological and physiological traits. In hydroponics and pot culture drought conditions, RWC, MSI, and yield were highly correlated with chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, chlorophyll fluorescence, stem girth, flower yield, and biomass. As a result, these traits can be considered useful selection indicators for drought tolerance. According to PCA, the traits chlorophyll a, chlorophyll b, chlorophyll a/b, total chlorophyll, carotenoids, RWC, and chlorophyll fluorescence were the most crucial traits that involved in genotype variability under stress contributing significantly to PC1 in pots and hydroponics. In hydroponics and pot culture, the variability was categorized into three and five principal components, respectively. These results offered useful information for chrysanthemum breeders aiming to select and improve drought tolerance through targeted selection and marker-assisted breeding strategies.

Drought affects chrysanthemum growth and yield, highlighting the need for reliable indicators of tolerance. This study evaluated 68 genetically diverse genotypes under hydroponics and pot culture using a completely randomized design to identify key physiological, biochemical and morphological traits linked to drought adaptation. Stress was imposed with 10 % polyethylene glycol (PEG) in hydroponics at the seedling stage and 60 kPa soil moisture tension in pots for 10 days at the vegetative stage based on our preliminary studies. Traits measured included chlorophyll content, carotenoids, relative water content (RWC), membrane stability index (MSI), canopy temperature depression (CTD), chlorophyll fluorescence, biomass and reproductive parameters. Correlation analysis revealed strong positive associations among chlorophyll content, RWC, MSI, CTD and fluorescence, suggesting coordinated mechanisms that preserve photosynthetic efficiency and cellular stability. Principal component analysis (PCA) identified chlorophyll b, fluorescence, biomass and reproductive traits as major contributors to phenotypic variation. The first few PCs explained 71.0 % variation in hydroponic control, 75.5 % in hydroponic stress, 61.6 % in pot control and 77.9 % in pot stress, indicating context-dependent adaptive strategies. Under hydroponic stress, chlorophyll a, total chlorophyll, biomass, chlorophyll b and carotenoids contributed strongly to both PC1 and PC2, with Punjab Singar, Violet, Gulmohar, Garden Beauty and Shwet excelling in these traits, while Autumn Joy and Naughty White were distinguished by flowers per plant and chlorophyll a/b. In contrast, under pot stress, no trait contributed simultaneously to both PCs. Overall, chlorophyll content, RWC, MSI, CTD, chlorophyll fluorescence and reproductive traits emerged as robust indicators for breeding drought-resilient chrysanthemum cultivars.

In the present study, interspecific hybrids between pummelo (Citrus maxima Merr.) and sweet orange (Citrus sinensis (L.) Osbeck cv. Mosambi) were developed, and 16 newly developed hybrids, along with their parental genotypes, were evaluated. New interspecific hybrids exhibited wide variations for the fruit quality traits and unique fruit properties. The fruit weight, length, width, peel thickness, core diameter, seed number, juice volume and juice content in new citrus hybrids varied from 296.73 to 562.45 g, 81.07-114.27 mm, 83.03-109.78 mm, 4.01-9.14 mm, 6.31-24.61 mm, 10-64.83, 75.67-197.50 mL and 22.91-48.24 % (w/w), respectively. The total soluble solids (TSS), titratable acidity (TA), TSS/TA ratio, BrimA (Brix minus acid index), reducing sugars, nonreducing sugar, and total sugar content in new hybrids ranged from 8.80 to 11.72 degrees Brix, 0.77-1.81 %, 5.74-12.28, 4.81-8.29, 2.88-4.99 %, 2.88-4.79 %, and 5.77-8.97 %, respectively. Additionally, the hybrids were also evaluated for peel color and sensory properties. Interspecific hybrids exhibited transgressive segregation for the studied physicochemical fruit quality traits. Heritability estimates revealed the underlying genetics of fruit quality traits based on the studied genotypes. Multivariate analysis, Pearson's correlation, and hierarchical clustering revealed key trait differentiation and associations among the hybrids. The hybridization between pummelo and sweet orange has successfully generated promising citrus hybrids. Among the new hybrids, SCSH-11-15/12, SCSH-11-9/13, SCSH-13-17/12, SCSH-9-10/12, and SCSH-17-19/13 were found to be promising based on fruit quality traits, sensory properties, and comparison with their parents, conducted over two seasons. The findings provide valuable insights for the citrus scion improvement program, aimed at enhancing fruit quality to exploit new hybrids for commercial cultivation.

Cucumber is an important vegetable crop cultivated in more than 150 countries around the world. Leaf curl disease (LCD), predominantly caused by tomato leaf curl New Delhi virus (ToLCNDV), is reported in cucumbers from different countries of South Asia and Europe and is associated with significant crop loss. The present study focuses on identifying cucumber genotypes resistant to the ToLCNDV, a significant threat to cucumber cultivation around the world. Besides, we have attempted to identify the genotypes with broad resistance to the Begomovirus complex present in the Indian subcontinent. There are no reports so far reporting effective resistance against LCD in cucumber caused by multiple Begomoviruses. Seven selected cucumber accessions from different regions of India were agro-inoculated with ToLCNDV and evaluated for disease symptoms and viral load at various time points postinoculation. Highly resistant genotypes DC-91 and DC-61 were identified, showing no symptoms and low viral accumulation. The resistance to ToLCNDV in cucumber appears to be recessive, with a 1:3 segregation ratio in the F2 population and a 1:1 ratio in the BC1P2 population, suggesting monogenic control. The study validates the resistance source to ToLCNDV from Indian-originated germplasm for future breeding programmes. The use of qPCR analysis allowed for precise quantification of the viral load, confirming the resistance in the Indian-originated germplasm. The economic impact of ToLCNDV on cucumber cultivation is significant, necessitating the development of resistant varieties. The present study emphasises the importance of host plant resistance as a sustainable strategy for managing ToLCNDV, as opposed to cultural practices and chemical treatments, which are limited in effectiveness and increase input costs. The identification of novel sources of resistance from the Indian originated lays the foundation for breeding ToLCNDV-resistant cucumber cultivars, contributing to the resilience of cucumber varieties against this devastating viral disease.

BACKGROUND:Rice is a primary cereal and staple food worldwide. Although rice cultivation requires a large amount of nitrogenous fertilizer, its nitrogen use efficiency (NUE) is only 20-50%. Therefore, in addition to soil and fertilizer management, it is crucial to improve the genetic potential of nitrogen use efficiency (NUE) in rice for this complex polygenic trait, which remains largely unexplored. METHODS AND RESULTS:In the present study, 20 promising novel genes identified earlier were first characterized in silico, followed by expression analysis in different tissues and growth stages under N-optimal and N-stress conditions in the contrasting rice genotypes N22 (poor NUE) and IR64 (superior NUE). We observed some special features in different genes, like the absence of essential coding sequences (ATG or stop codons), untranslated transcripts (lncRNAs), overlapping gene sequences, and genes with antisense transcripts. Due to this complexity, the functions of these genes are yet to be determined. Expression profiling under nitrogen stress showed upregulation in both vegetative and reproductive stages in N22, while in IR64, upregulation was observed at the seedling stage and downregulation during the reproductive stage. CONCLUSION:Apart from functional proteins, nitrogen stress-responsive genes in rice also transcribe into lncRNAs, some of them showing allelic variation across genotypes. These genes are regulated by light and hormone-responsive promoter elements under nitrogen stress. This study improves the understanding of important N-stress responsive genes and alleles in the two contrasting genotypes. The present study aims to identify promising genes with unique features for their functional validation, and for supporting the molecular breeding programs to develop rice lines with improved NUE.

Developing an efficient and reproducible regeneration protocol holds paramount significance for advancing genetic transformation technologies in rice, facilitating their utilisation in crop improvement. Nagina 22 (N22), a climate-resilient Aus-type rice genotype known for its tolerance against multiple stresses, lacks a standardised transformation protocol, limiting its utilisation as a background for genetic transformation. This study reports, for the first time, a highly efficient transformation and regeneration protocol for N22 using a CRISPR/Cas9 vector. Mature seeds were used to induce embryogenic calli on CHU(N6)-based callus induction media (CIM) with varying concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D). The highest callus induction efficiency ( 94

Glycolipid transfer protein (GLTP) genes are recognized for their role in stress adaptation in animals. In this study, for the first time, seventy-four GLTP genes were identified across ten Oryza species, with each species containing 6-9 genes. These genes exhibited strong synteny and collinearity, maintaining conserved chromosomal positions across all Oryza species. Gene duplication events were frequent, accounting for 61.9 % of the GLTP genes, and their Ka/Ks ratios (<1) suggested purifying selection and evolutionary conservation. All identified genes encoded proteins with a single GLTP domain and clustered into three major clades: two clades containing distinct sets of GLTP genes and the third comprising ACD11-like genes. Notably, the GLTP2-miR414 regulatory module was supported by both bioinformatic predictions and experimental validation. Structural and functional analyses revealed ACD11 and GLTP3 as the most promising candidate genes for stress responses. Functional validation of GLTP3 by candidate gene analysis using a rice minicore diversity panel revealed 14 significant marker-trait associations, including two markers specifically associated with malondialdehyde content-a key indicator of lipid peroxidation-under heat stress conditions. This is the first report on the GLTP genes in rice with promising leads for their utilization in stress breeding.

Powdery mildew (PM) caused by Erysiphe necator (Schw.) Burrill is one of the most important constraints in enhancing grapevine productivity. The study focused on identifying stable and highly resistant grapevine genotypes against PM across multiple environments, while assessing conditions favouring optimal trait expression. Forty-two genotypes were evaluated over three consecutive seasons (2021-2023) using disease severity index (DSI), morphological and biochemical analysis. Resistant genotypes, such as Vitis parviflora, Pusa Navrang and V. jacquemontii exhibited lower stomatal density, increased leaf thickness and enhanced antioxidant activities. Significant G x S interactions were employed using additive main effects and multiplicative interaction and genotype (AMMI) and genotype-environment interaction (GGE) biplot analysis based on disease severity index data. The estimation of stability indices, i.e. WAASB is used for selecting highly resistant genotypes. The multi-trait stability index (MTSI) method in evaluating 18 traits highlighted V. parviflora, Chardonnay, 110 Richter, Pusa Navrang and Male hybrid as the most promising genotypes. These genotypes exhibited lower DSI and no notable changes in photosynthetic pigments in diseased leaves. High heritability of PAL, PPO and total phenols underscores their potential as key targets for selection. Similarly, high heritability of the DSI (81-93 %) confirms a strong genetic basis, with V. parviflora, 110 Richter, Pusa Navrang and Male Hybrid emerging as the most stable resistant genotypes. These genotypes were identified as stable performers under natural PM pressure and could serve as candidates for breeding programs, enabling the development of resistant grape cultivars and thus reducing the need for fungicide use in disease-prone regions.

With climate change intensifying global temperatures, developing heat-resilient rice varieties has become a critical challenge for future food security. In this study, we explored the allelic variation of a Glycolipid Transfer Protein (GLTP) gene in rice and its role in physiological adaptation to heat stress. A diverse panel of 96 rice genotypes was evaluated over two seasons under both control and heat-stress environments for five key traits: relative water content, membrane stability index, malondialdehyde content, antioxidant activity, and chlorophyll concentration. Sequence analysis of the GLTP gene and its promoter revealed 172 mutations, including 14 coding SNPs that defined 9 haplotypes and 6 protein isoforms. Association mapping identified several significant SNP-trait linkages, particularly in intronic and promoter regions, with strong effects on oxidative stress indicators. Notably, a rare haplotype, Hap4, comprising a single genotype (NERICA Line 44) exhibited superior physiological performance under heat stress. The poor haplotype, Hap9, was found to be structurally distinct at the C-terminal domain, as predicted by the AlphaFold3 modelling. These findings highlight the functional importance of natural non-coding variation and demonstrate how specific GLTP3 alleles can enhance thermo-tolerance. This work provides novel molecular insights and valuable allelic resources to accelerate the breeding of climate-smart rice cultivars.