Search Results (780)

To streamline germplasm preservation, enhance resource utilization, and improve breeding efficiency, a core germplasm bank was established using 24 phenotypic traits and DNP markers from 155 pepper resources across various regions. Selection of the optimal core germplasm was based on intra-group retention ratio, overall retention scale, and intra-group stepwise clustering retention. Evaluation of phenotypic trait data for the core germplasm utilized mean, variance, range, and coefficient of variation, with principal component analysis confirming the selection. For molecular evaluation, the core germplasm pre-selection plan was based on SSR clustering, allele retention ratio, and Shannon-Weaver diversity index. This approach resulted in a core germplasm of 41 resources, including 6 var. fasciculatum, 7 var. grossum, 3 var. cerasiorme, 6 var. conoides, and 19 var. longum, representing the maximum phenotypic retention and genetic diversity of the 155 pepper resources. Additionally, a core germplasm of 32 resources was generated based on SSR markers, retaining all 54 polymorphic loci. By integrating phenotypic and molecular core collections, a combined core collection of 57 varieties was developed. This collection achieved a 92.55% phenotype retention ratio and a 100% polymorphism site retention ratio. With a 90% compression ratio, it encapsulates the broad genetic diversity of the original germplasm, serving as a comprehensive resource for further research and breeding applications. Full article

Yellow leaf mutations have been widely used to study the chloroplast structures, the pigment synthesis, the photosynthesis mechanisms and the chlorophyll biosynthesis pathways across various species. For this study, a spontaneous mutant with the yellow leaf color named 96-140YBM was employed to explore the primary genetic elements that lead to the variations in the leaf color of hot peppers. To identify the pathways and genes associated with yellow leaf phenotypes, we applied sequencing-based Bulked Segregant Analysis (BSA-Seq) combined with BSR-Seq. We identified 4167 differentially expressed genes (DEGs) in the mutant pool compared with the wild-type pool. The results indicated that DEGs were involved in zeatin biosynthesis, plant hormone signal transduction, signal transduction mechanisms, post-translational modification and protein turnover. A total of 437 candidates were identified by the BSA-Seq, while the BSR-Seq pinpointed four candidate regions in chromosomes 8 and 9, containing 222 candidate genes. Additionally, the combination of BSA-Seq and BSR-Seq showed that there were 113 overlapping candidate genes between the two methods, among which 8 common candidates have been previously reported to be related to the development of chloroplasts, the photomorphogenesis and chlorophyll formation of plant chloroplasts and chlorophyll biogenesis. qRT-PCR analysis of the 8 common candidates showed higher expression levels in the mutant pool compared with the wild-type pool. Among the overlapping candidates, the DEG analysis showed that the CaKAS2 and CaMPH2 genes were down-regulated in the mutant pool compared to the wild type, suggesting that these genes may be key contributors to the yellow leaf phenotype of 96-140YBM. This research will deepen our understanding of the genetic basis of leaf color formation and provide valuable information for the breeding of hot peppers with diverse leaf colors. Full article

PLCPs (papain-like cysteine proteases) are one of the most abundant groups of cysteine proteases and play vital roles in multiple processes. The pepper (Capsicum annuum) is an important Solanaceae vegetable crop; its commercial hybrid seeds are widely used in production. Male sterility is a valuable trait for hybrid seed production. However, the function of PLCPs and the underlying mechanisms of male sterility in peppers remain unclear. In this study, we comprehensively identified the PLCP gene family in peppers, identifying 31 CaPLCPs. A phylogenetic analysis classified 31 members into eight clades. These CaPLCPs were unevenly distributed across eight chromosomes, and five segmental duplicated pairs were observed. The promoter cis-acting element analysis indicated that CaPLCP promoters contained abundant hormone-responsive and stress-responsive cis-elements, suggesting that CaPLCPs may play important roles in responding to abiotic stress, such as drought and low temperatures, as well as in plant immunity. The qRT-PCR analysis demonstrated that the expression levels of CaPLCP1, CaPLCP5, CaPLCP11, CaPLCP12, CaPLCP13, CaPLCP17, CaPLCP19, and CaPLCP21 were significantly reduced in the flowers of MS (male sterile pepper) at least at one stage, indicating their potential roles as regulatory factors in pepper male sterility. These findings provide important insights into the functional analysis of the PLCP gene family in peppers and other species, laying a crucial foundation for understanding the mechanisms of male sterility in peppers. Full article

Fruit weight is an important agronomic trait in pepper production and is closely related to yield. At present, many quantitative trait loci (QTL) related to fruit weight have been found in pepper; however, the genes affecting fruit weight remain unknown. We analyzed the fruit weight-related quantitative traits in an intraspecific Capsicum annuum cross between the cultivated species blocky-type pepper, cv. Qiemen, and the bird pepper accession, “129−1” (Capsicum annuum var. glatriusculum), which was the wild progenitor of C. annuum. Using the QTL-seq combined with the linkage-based QTL mapping approach, QTL detection was performed; and two major effects of QTL related to fruit weight, qFW2.1 and qFW3.1, were identified on chromosomes 2 and 3. The qFW2.1 maximum explained 12.28% of the phenotypic variance observed in two F₂ generations, with the maximum LOD value of 11.02, respectively; meanwhile, the qFW3.1 maximum explained 15.50% of the observed phenotypic variance in the two F₂ generations, with the maximum LOD value of 11.36, respectively. qFW2.1 was narrowed down to the 1.22 Mb region using homozygous recombinant screening from BC₂S₂ and BC₂S₃ populations, while qFW3.1 was narrowed down to the 4.61Mb region. According to the transcriptome results, a total of 47 and 86 differentially expressed genes (DEGs) in the candidate regions of qFW2.1 and qFW3.1 were identified. Further, 19 genes were selected for a qRT-PCR analysis based on sequence difference combined with the gene annotation. Finally, Capana02g002938 and Capana02g003021 are the most likely candidate genes for qFW2.1, and Capana03g000903 may be a candidate gene for qFW3.1. Taken together, our results identified and fine-mapped two major QTL for fruit weight in pepper that will facilitate marker-assistant breeding for the manipulation of yield in pepper. Full article

This study focuses on describing the diversity of pesticides, the knowledge and behaviors of their use, and the acute poisoning symptoms (APS) derived from their exposure from two agricultural production systems (papaya—Carica papaya L.- and chili—Capsicum annuum L.-) in Oaxaca, Mexico. Through surveys, sociodemographic information, characteristics of the production system, knowledge and behaviors in the handling of pesticides, and APS perceived by users were captured. Papaya producers are younger, have fewer years of activity, and have larger agricultural areas than chili producers. Insect attacks and diseases are an essential factor for the application of pesticides. Thirty-one active ingredients (Ais) were identified in papaya and thirty-seven in chili, predominantly insecticides and fungicides of toxicological category IV. Approximately 50% of users apply mixtures of different Ais, have little knowledge and inappropriate behavior in their handling, and report up to five acute pesticide poisoning symptoms, mainly burning and irritation of the skin, burning eyes, itchy skin, runny nose, headache, and watery eyes. The production of papaya and chili are relevant activities for generating economic income, but they risk the producer’s and their family’s health. Both systems are a potential scenario for the manifestation of diseases due to exposure to pesticides in the medium and long term. Full article

This study was conducted to identify resistant pepper accessions against the destructive disease bacterial wilt (BW) caused by Ralstonia solanacearum. A total of 338 pepper (Capsicum species) germplasms collected from different countries and deposited in the National Agrobiodiversity Genebank, Rural Development Administration (RDA), Republic of Korea, were evaluated. The evaluated accessions comprise samples from five distinct species: Capsicum annuum (213), Capsicum baccatum (47), Capsicum chinense (45), Capsicum frutescens (31), and Capsicum chacoense (2). Disease severity scores were recorded over four consecutive weeks and showed an increase in severity from initial inoculation to the end of the evaluation period. A strong correlation was observed between week 1 and 2, as well as between week 3 and 4. Ten resistant pepper accessions were identified. All selected accessions consistently exhibited low disease scores ranging from 0 to 1 throughout the observation period. These accessions belong to C. chinense (2), C. annuum (6), C. chacoense (1), and C. frutescens (1). Accessions such as IT236738 (C. chinense) and IT283498 (C. chinense) were demonstrated to have high resistance, showing no symptoms over all four weeks. Other accessions belonging to C. annuum (IT247232 and IT236340) and C. chacoense (IT158713) maintained a disease score of 0 (no symptoms) for the first three consecutive weeks; however, they developed symptoms with a score of 1 in the fourth week. Other important characteristics of the resistant materials were evaluated, including carotenoids and fruit characteristics. These accessions have important traits beyond resistance to the destructive pepper disease. They will serve as promising resources for breeding resistant pepper varieties against BW to enhance productivity. Full article

Biochar return to the field has been widely explored, but there is a problematic disconnect between biochar preparation and biochar return to the field. In this study, soybean straw is used as a raw material and is sieved into two components: 60-mesh (0.250 mm) and 110-mesh (0.130 mm). Four kinds of biochar were obtained by pyrolysis under the condition of no heat preservation and heat preservation for 60 min. The biochar was applied to the soil, and the effects of biochar on soil and capsicum growth were analyzed by Spearman correlation. Compared with the control group, soil pH, soil electrical conductivity, and soil organic matter decomposition were increased by 0.58, 101 μs/cm, and 9.48%, respectively. The fruit quantity, plant height, water, fat, soluble solid, and titrable acidity of capsicum were increased by 1, 0.55, 0.08, 0.62, 0.67, and 0.7 times, respectively. Spearman correlation analysis showed that soil properties and capsicum growth were most affected by biochar’s specific surface area (SSA). Therefore, increasing the biomass mesh number and heat preservation time is beneficial to increasing the SSA of biochar and facilitating the return of biochar to the field and the best preparation conditions are 110-mesh soybean straw biomass pyrolysis and heat preservation for 60 min. Full article

Capsicum annuum L. is extensively cultivated in subtropical and temperate regions globally, respectively, when grown in a medium with 8 holding significant economic importance. Despite the availability of genome sequences and editing tools, gene editing in peppers is limited by the lack of a stable regeneration and transformation method. This study assessed regeneration and transformation protocols in seven chili pepper varieties, including CM334, Zunla-1, Zhongjiao6 (ZJ6), 0818, 0819, 297, and 348, in order to enhance genetic improvement efforts. Several explants, media compositions, and hormonal combinations were systematically evaluated to optimize the in vitro regeneration process across different chili pepper varieties. The optimal concentrations for shoot formation, shoot elongation, and rooting in regeneration experiments were determined as 5 mg/L of 6-Benzylaminopurine (BAP) with 5 mg/L of silver nitrate (AgNO₃), 0.5 mg/L of Gibberellic acid (GA₃), and 1 mg/L of Indole-3-butyric acid (IBA), respectively. The highest regeneration rate of 41% was observed from CM334 cotyledon explants. Transformation optimization established 300 mg/L of cefotaxime for bacterial control, with a 72-h co-cultivation period at OD₆₀₀ = 0.1. This study optimizes the protocols for chili pepper regeneration and transformation, thereby contributing to genetic improvement efforts. Full article

Plant glutathione peroxidases (GPXs) are important enzymes for removing reactive oxygen species in plant cells and are closely related to the stress resistance of plants. This study identified the GPX gene family members of pepper (Capsicum annuum L.), “CM333”, at the whole-genome level to clarify their expression patterns and enzyme activity changes under abiotic stress and ABA treatment. The results showed that eight CaGPX genes were unevenly distributed across four chromosomes and one scaffold of the pepper genome, and their protein sequences had Cys residues typical of the plant GPX domains. The analysis of collinearity, phylogenetic tree, gene structure, and conserved motifs indicated that the CaGPX gene sequence is conserved, structurally similar, and more closely related to the sequence structure of Arabidopsis. Meanwhile, many cis elements involved in stress, hormones, development, and light response were found in the promoter region of the CaGPX gene. In addition, CaGPX1/4 and CaGPX6 were basically expressed in all tissues, and their expression levels were significantly upregulated under abiotic stress and ABA treatment. Subcellular localization showed that CaGPX1 and CaGPX4 are localized in chloroplasts. Additionally, the variations in glutathione peroxidase activity (GSH-Px) mostly agreed with the variations in gene expression. In summary, the CaGPXs gene may play an important role in the development of peppers and their response to abiotic stress and hormones. Full article

The pepper weevil, Anthonomus eugenii Cano, is an economically important pest of cultivated peppers (Capsicum annuum) in tropical and subtropical regions of the world. This study aimed to ascertain the spatial distribution of pepper weevil infestation across various fields in Miami Dade County, South Florida. The spatio-temporal dynamics of pepper weevil were evaluated using 144 sample points within each of seven pepper fields. The data were analyzed using three different geospatial techniques, spatial analysis by distance indices (SADIE), Moran’s I, and Geary’s C, to determine the spatial distribution of pepper weevil. The SADIE analysis revealed a significant aggregation distribution in 18 out of 30 sampling dates across all fields. The results from Geary’s C and Moran’s I indices indicated a positive spatial autocorrelation (spatial clustering/aggregation) of pepper weevil regardless of field or pepper types. Overall, the findings from this study depict an aggregated spatial distribution pattern of pepper weevil populations, characterized by a tendency for aggregation that transitions to a more uniform distribution as the season progresses. Full article

Vertical indoor farming (VIF) with hydroponics offers a promising perspective for sustainable food production. Intelligent control of VIF system components plays a key role in reducing operating costs and increasing crop yields. Modern machine vision (MV) systems use deep learning (DL) in combination with camera systems for various tasks in agriculture, such as disease and nutrient deficiency detection, and flower and fruit identification and classification for pollination and harvesting. This study presents the applicability of MV technology with DL modelling to detect the growth stages of chilli plants using YOLOv8 networks. The influence of different bird’s-eye view and side view datasets and different YOLOv8 architectures was analysed. To generate the image data for training and testing the YOLO models, chilli plants were grown in a hydroponic environment and imaged throughout their life cycle using four camera systems. The growth stages were divided into growing, flowering, and fruiting classes. All the trained YOLOv8 models showed reliable identification of growth stages with high accuracy. The results indicate that models trained with data from both views show better generalisation. YOLO’s middle architecture achieved the best performance. Full article

As a crucial member of the gene family involved in the biosynthesis of strigolactones, D27 plays an important regulatory role in plant branching and root development, which is essential for field management and yield increase in peppers (Capsicum annuum L.). To comprehensively understand the characteristics of the pepper D27 gene family, we identified three CaD27 genes. By analyzing their physicochemical properties, phylogenetic relationships, gene structures, promoters, and expression patterns in different tissues, the characteristics of the CaD27 gene family were revealed. The research results showed that these three CaD27 genes are located in three different chromosomes. Evolutionary analysis divided the members of CaD27 into three groups, and gene collinearity analysis did not find any duplicates, indicating the diversity and non-redundancy of the CaD27 gene family members. In addition, we identified and classified cis-elements in the promoter regions of CaD27 genes, with a relatively high proportion related to light and plant hormone responses. Expression pattern analysis showed that CaD27.1 is expressed in leaves, while CaD27.2 is expressed in roots, indicating tissue specificity. Furthermore, protein interaction predictions revealed an interaction between D27.2 and CCD7. This study provided important insights into the function and regulatory mechanisms of the CaD27 gene family and the role of strigolactones in plant growth and development. Full article

Climate change is an important concern worldwide. This huge change is causing a negative impact on crop productivity throughout the whole world and shows some drastic effects on sensitive crops including sweet pepper and other kinds of chilies. These stresses have a negative effect on vegetable growth, fruit quality, and fruit yield. Besides these stresses, accurate planting time is the utmost factor in increasing the crop potential and its productivity. Therefore, this study aimed to evaluate the optimal planting date and best-performing cultivar for sweet pepper to maximize crop productivity, growth, yield, and fruit shelf life under the impacts of climate change. The experiment was conducted in Multan, Pakistan (30° 25 N and 71° 30 E). In this experiment, four planting dates (10 January, 25 January, 10 February, and 25 February) with three cultivars (Ganga, Winner, and Savio) were grown with three replications (each year) during 2020 and 2021. Our findings showed that plant growth, fresh and dry biomass, yield, and yield attributes were statistically higher in earlier plantings, and lower in delayed planting. Regarding the cultivars in both years, ‘Winner’ performed better in all growth and yield parameters as compared to other growing cultivars. Lower weight loss and decay incidence were reported in ‘Winner’ cultivar. Additionally, ‘Winner’ cultivar showed a higher sensory score as compared to the other cultivar in both years. From the results, we conclude that the nursery of sweet pepper plants should be planted on the 25 January to attain higher crop productivity, and the cultivar ‘Winner’ showed promising effects so it should be planted for better yield. Full article

The jalapeño pepper is a vegetable of great economic importance worldwide. However, low germination efficiency, weak seedlings, and a high mortality rate during transplant compromise the viability and sustainability of the crop. An innovative solution is the nanopriming technique, an emerging and novel technology, which involves the imbibition of seeds for a specific period using mineral nanoparticles. The addition of micronutrients such as zinc and molybdenum has been used in seed germination and early seedling development due to their crucial roles. The aim of this study was to evaluate the effectiveness of using zinc–molybdenum nanopriming in jalapeño pepper on germination and early growth. The results showed that applying nanopriming (124–10 mg L⁻¹ of zinc–molybdenum) promotes the effectiveness on the imbibition and germination of jalapeño pepper seeds, resulting in heavier seeds with a better initial absorption. This method not only improves germination rates and seedling vigor, but also points towards more sustainable and efficient agriculture. Building on these findings, the zinc–molybdenum nanopriming method could potentially transform jalapeño pepper cultivation by enhancing seed quality and resilience. Nanopriming could help increase crop yields and minimize reliance on chemical inputs, such as fertilizers and pesticides, which might reduce production costs and environmental impact. Full article

Pepper is an economically important vegetable worldwide, containing various specialized metabolites crucial for its development and flavor. Capsaicinoids, especially, are genus-specialized metabolites that confer a spicy flavor to Capsicum fruits. In this work, two pepper cultivars, YB (Capsicum frutescens L.) and JC (Capsicum baccatum L.) pepper, showed distinct differences in the accumulation of capsaicin and flavonoid. However, the molecular mechanism underlying them was still unclear. Metabolome analysis showed that the JC pepper induced a more abundant accumulation of metabolites associated with alkaloids, flavonoids, and capsaicinoids in the red ripening stages, leading to a spicier flavor in the JC pepper. Transcriptome analysis confirmed that the increased expression of transcripts associated with phenylpropanoid and flavonoid metabolic pathways occurred in the JC pepper. Integrative analysis of metabolome and transcriptome suggested that four structural genes, 4CL7, 4CL6, CHS, and COMT, were responsible for the higher accumulation of metabolites relevant to capsaicin and flavonoids. Through weighted gene co-expression network analyses, modules related to flavonoid biosynthesis and potential regulators for candidate genes were identified. The promoter analysis of four candidate genes showed they contained several cis-elements that were bonded to MYB, bZIP, and WRKY transcription factors. Further RT-qPCR examination verified three transcription factors, MYB, bZIP53, and WRKY25, that exhibited increased expression in the red ripening stage of the JC pepper compared to YB, which potentially regulated their expression. Altogether, our findings provide comprehensive understanding and valuable information for pepper breeding programs in the future. Full article