Local pepper (Capsicum annuum L.) landraces represent an important source of genetic diversity, particularly for traits related to seed germination and early seedling development. This study aimed to evaluate emergence behavior and cotyledon morphological traits in nine Tunisian hot pepper landraces under controlled conditions. Emergence parameters, including days to emerge, emergence percentage, and mean emergence time, were recorded, while cotyledon colour, shape, length, and width were assessed at the cotyledon stage. Significant differences were observed among landraces in days to emergence and mean emergence time, indicating variation in germination kinetics and early seed vigor. Cayenne, D’hirat, Baklouti, and Kairouan exhibited faster and more synchronized emergence, whereas Semmene, Beldi, and Nabeul showed delayed emergence. Despite these differences, germination percentage remained high across all landraces (95-100%), reflecting good seed viability. Cotyledon colour and shape were uniform, with all landraces displaying green, lanceolate cotyledons; however, cotyledon length and width varied significantly, highlighting genetic diversity in early seedling morphology. These results demonstrate that germination dynamics and cotyledon traits are effective indicators of early vigor and morphological variation among local pepper landraces, providing useful criteria for germplasm characterization, conservation, and breeding programs.

Seed longevity is a critical determinant of crop performance and germplasm conservation, yet strong genotype-dependent variability remains poorly documented in pepper (Capsicum annuum L.). This study investigates the impact of a decade of storage on the germination performance of three Tunisian genotypes (Nabeul, Mahdia and Kairouan). Seed lots harvested in 2013 and 2023 were evaluated under controlled conditions using viability, germination speed and vigor metrics. Long-term storage caused significant reductions in viability, germination rate, and vigor across genotypes, reflecting pronounced physiological deterioration. Fresh seeds exhibited consistently higher germination percentage, capacity, speed index, coefficient of velocity, and germination vigor index values, together with markedly lower mean germination time. Strong genotype-specific responses were identified: Nabeul maintained high germination and vigor regardless of storage duration, whereas Mahdia showed excellent performance when fresh but severe deterioration after 10 years; Kairouan displayed intermediate sensitivity. These findings highlight substantial genetic variation in seed aging tolerance and underscore the value of long-lived genotypes such as Nabeul for seed conservation, breeding programs, and long-term germplasm management.

The assessment of water stress levels in plants should be an essential part of precise irrigation management, and a good and quick method is useful in plant phenotyping. There are many options for this task, but the effectiveness varies between crop species and environments. Apparently open field applications face the most difficulties. This study aimed to test a large number of vegetation indices (VIs) and multivariate models based on hyperspectral reflectance data (325–1075 nm) regarding their correlation and prediction abilities to leaf stomatal conductance, relative water content (RWC), and detailed chlorophyll and carotenoid components.Data of the abovementioned variables was collected during three consecutive growing seasons in processing tomato cultivated under different water supply regimes to provide data with varying water stress levels. Then the relation of the measured variables to 226 VIs was tested created according to the formulas collected in the Index DataBase, established within the IDB Project. New VIs were also developed derived from the most important variables of the ML algorithms, customised to tomato water stress assessment. Standard normal variate and its combination with Savitzky-Golay first derivative were used for pre-processing the spectra, and principal component regression (PCR), partial least squares regression (PLSR), elastic net (ENET), support vector regression (SVR), random forest (RF) and extreme gradient boosting (XGB) algorithms were tested.The newly developed indices outperformed the existing formulas, except in the case of β-carotene. The most reliable index was developed for RWC estimation; that was the difference of the reflectance on the 986 and 701 nm wavelengths.The ENET and SVR algorithms produced the best models depending on the pre-processing method. The blue, near-infrared (NIR), and green regions, respectively, were the most important regarding all models according to the variable importance analysis. The model with the best metrics was developed for chlorophyll-a (R2=0.82, nRMSE=11%, RPIQ=2.41), followed by RWC (R2=0.72, nRMSE=14%, RPIQ=2.53).

Peaches are a climacteric and highly perishable fruit with a short shelf life under ambient storage conditions which hampers further marketing and leads often to economic losses. Consequently, searching for pre-storage treatments to maintain shelf life and preserve the quality of peach fruit is an important task. Therefore, the present study was designed to investigate the efficiency of marigold flower extract (MFE) application on the shelf life and some quality attributes of peach fruit under ambient storage conditions. Peach fruit of cv. Early grand was treated with different concentrations of MFE (control, 10

Pepper is one of the most economically important vegetable crops grown and consumed in Tunisia. Interest in assessing bioactive compounds with antioxidant capacity and potential health benefits in pepper and pepper-based products is increasing. There is limited information undertaking the chemical properties and quality of commercial red-hot pepper pastes (harissa) in Tunisia compared to traditionally prepared varieties. The variability in ascorbic acid, phenolic, and carotenoid contents and antioxidant activity of ten red-hot pepper pastes covering almost the commercial types available in Tunisian hypermarkets were determined and compared with traditionally processed harissa. Ascorbic acid, phenolic, and carotenoid contents and antioxidant activity varied significantly between different red-hot pepper paste. Traditional home-processed harissa outperformed different commercial pepper pastes in terms of bioactive compounds. Ascorbic acid varied from 57.33 to 210.41 mg/100 g FW. The levels of phenolics in different studied red-hot pepper paste varied from 207.34 to 317.24 mg GAE/100 g FW. Significant differences were found also in carotenoids content between different red-hot pepper pastes (coded as CH1-10) ranging from 284.78 mg β-CaE/kg FW in ‘CH2’ to 761.69 mg β-CaE/kg FW in ‘CH8’. ‘CH9’ showed the highest antioxidant activity attaining 2,812 μmol TE/100 g FW. Hydrophilic antioxidant activity was negatively and significantly correlated with ascorbic acid content ( r = −0.700; P < 0.05) and carotenoids content ( r = −0.674; P < 0.05). This study highlighted the variability in different commercial hot pepper pastes consumed in Tunisia, with respect to quality attributes, and showed the importance of optimising a traditional-like process to create new labels and quality suitable for new consumer demands.

This study assessed the morphological diversity of floral traits among sixteen Tunisian Capsicum annuum landraces grown under open-field conditions. Significant variation was recorded for all examined traits, including days to flowering, corolla length, anther and filament length, and calyx diameter. Flowering time ranged from 43 to 133 days, indicating a wide phenological divergence among genotypes. Most landraces exhibited pendant flower orientation, while a few showed intermediate positions. Correlations ranged from r = 0.69 to r = 0.85 among corolla, anther, filament, and calyx dimensions, suggesting coordinated floral development, whereas flowering time was largely independent of flower size. Cluster analysis distinguished early- and late-flowering groups, reflecting contrasting adaptive strategies and potential genetic differentiation. Overall, the observed floral variability underscores the diversity present within Tunisian pepper germplasm, offering valuable opportunities for breeding programs targeting earliness, reproductive efficiency, and environmental adaptability.

The application of plant derived extracts is increasingly becoming effective, environmentally friendly, innovative alternative approaches used to manage and control postharvest senescence, preserving quality, and maintaining storage life of horticultural crops. Neem extract is characterized by antioxidative, antifungal, antibacterial properties and contains several bioactive compounds which help reduce postharvest senescence and prolong shelf life. Peach fruits are perishable with short shelf life attributable to elevated respiration and transpiration rate afterward postharvest. Thus, contemporary research aimed to examine the impact of neem leaf extract (NLE) application using different concentrations (control, 10%, 20%, and 30% NLE) on the antioxidant activity and physiochemical characteristics of peach fruit over nine-day period under room temperature storage. Results indicated that NLE (30%) significantly diminished weight loss, decay, and respiration rate whereas yielding higher firmness than control. Moreover, peach fruit treated with NLE showed higher titratable acidity compared to untreated fruits, but their ripening index and soluble solids content were lower than control fruits. Furthermore, NLE-treated peach fruits preserved a much greater total phenolic and ascorbic acid content associated with lower total, reducing and non-reducing sugar contents than the control fruits. Enzymatic antioxidant activity including superoxide dismutase, peroxidase, catalase and protein content were significantly higher in 30%-treated peach fruit NLE compared to control fruits. Practically, these verdicts suggested that postharvest application of NLE 30% might be a useful strategy for maintaining peach fruit quality and extending its storage life for up to nine days.

Climate change poses significant challenges for the rainfall patterns at the global and regional scales which affect the production of canola (Brassica napus L.) plants. This research was designed to investigate and quantify the impact of water stress during the seedling stage on the morphology and physiology of two varieties of Pioneer hybrid canola (Y84 and Pr73) under a controlled environment chamber. Two-month-old canola seedlings were arranged in a randomized complete block design (RCBD) and treated with two-water regimes: 25–30

Agriculture faces great challenges to overcome global warming and improve system sustainability, requiring access to novel genetic diversity. So far, wild populations and local landraces remain poorly explored. This is notably the case for the two diploid species, Brassica oleracea L. (CC, 2n=2x=18) and B. rapa L. (AA, 2n=2x=20). In order to explore the genetic diversity in both species, we have collected populations in their centre of origin, the Mediterranean basin, on a large contrasting climatic and soil gradient from northern Europe to southern sub-Saharan regions. In these areas, we also collected 14 populations belonging to five B. oleracea closely related species. Our objective was to ensure the absence of species misidentification at the seedling stage among the populations collected and to describe thereafter their origins. We combined flow cytometry, sequencing of a species-specific chloroplast genomic region, as well as cytogenetic analyses in case of unexpected results for taxonomic verification. Out of the 112 B. oleracea and 154 B. rapa populations collected, 103 and 146, respectively, presented a good germination rate and eighteen populations were misidentified. The most frequent mistake was the confusion of these diploid species with B. napus. Additionally for B. rapa, two autotetraploid populations were observed. Habitats of the collected and confirmed wild populations and landraces are described in this study. The unique plant material described here will serve to investigate the genomic regions involved in adaptation to climate and microbiota within the framework of the H2020 Prima project ‘BrasExplor’.

Given the global importance of sweet potatoes as a nutrient-rich staple food, this research aimed to find the optimal cultivation practices to improve both yield and carotenoid content, with a particular focus on enhancing β-carotene content. In this study, the effects of different cultivation methods and plant densities on the agronomic parameters, physiological characteristics and carotenoid content of the ‘Beauregard’ variety were investigated across two consecutive growing seasons. Besides storage root yield, the key physiological parameters, including SPAD and chlorophyll fluorescence (Fv/Fm), were monitored to assess plant health and photosynthetic performance. Carotenoid content, including trans-β-carotene, cis-β-carotene, and ζ-carotene, was quantified using high-performance liquid chromatography (HPLC). Results indicated that the ridge cultivation method, particularly when combined with twin-row planting, consistently produced the highest yields, reaching the maximum of 40.87 t ha−1 in 2020. The flat cultivation method, especially in simple rows, showed the lowest yield. The analysis revealed that plant density had a more pronounced effect on yield and carotenoid content than the ridge or flat cultivation method alone. The maximum β-carotene content was achieved in the simple row (17,500 plants/ha) treatment planted on ridges with 247 µg/g. Significant correlations between both SPAD readings and Fv/Fm and yield were revealed, but no correlations with storage root carotenoid content were found. This suggests that, while these leaf physiological traits can be used to estimate the yield, they are not directly associated with the carotene content of the storage root. The study highlights the ridge cultivation and 35,000 plants/ha method as a stable and high-yielding option for ‘Beauregard’ in terms of improving and balancing the yield and carotenoid content; however, reducing the plant density resulted in elevated carotenoid content with significant yield reductions. The findings contribute to the understanding of how agronomic practices influence the nutritional and physiological traits of sweet potatoes, with implications for improving food security and nutritional outcomes in sweet potato cultivation.

Fresh fruits of five guava ( Psidium guajava L.) cultivars were assessed for ascorbic acid (AA) content and enzymatic antioxidants (superoxide dismutase [SOD] and ascorbate peroxidase [APX]) activities, while extracted peel and pulp samples were analyzed for total phenol (TP) and total flavonoids (TFs). The hydrophilic and lipophilic antioxidant activity was evaluated using six different analytical assays. We noticed significant differences in the antioxidant compounds (AA, TP, and TF). SOD and APX activities varied from ∼54 to 71 and ∼41 to 59 U/g FW, respectively. Cv. KG Guava had the highest TP (in both hydrophilic and lipophilic peel and pulp fractions) and TF (in hydrophilic pulp and lipophilic peel and pulp fractions). Therefore, the strongest antioxidant potential was exhibited by KG Guava using most of the assays, which was followed by the cultivars Kimchu and Salithong. The results provide valuable information about antioxidant potential of guava peel and pulp fractions, which is essential for their future application in the food and health industry.

Potato ( Solanum tuberosum L.) is a staple food widely consumed in Tunisia and represents a source of various secondary metabolites with human health benefits. However, cold storage of potato tuber affects their bioactive properties and functional quality. Despite the importance of this fact, few studies have examined the effects of extended cold storage on potato tubers quality. Therefore, the objective of the present work was to evaluate the effect of cold storage on the main quality traits of different potato genotypes grown in Tunisia. This investigation focused on four cultivated potato varieties including three commercial (Selena, Elbeidha, and Naima) and a selected clone CL27 grown under late cropping season conditions with planting at the beginning of autumn and a winter tuberization. The tubers from this trial were stored for 90 days at 8°C. The results obtained showed that quality traits of potato tubers were strongly influenced by storage at 8°C throughout 90 days. Additionally, disregarding the genotype, total carotenoids, phenolics, and flavonoids contents increased significantly following 90 days storage at 8°C. However, genotypic differences underlying the antioxidant activity in both hydrophilic and lipophilic fractions were detected suggesting their sensibility to cold storage. This study might be useful for breeders working on potato genotypes suitable for extended storage duration and for growers storing their material for extended period under low temperature.

The tomato as a raw material for processing is globally important and is pivotal in dietary and agronomic research due to its nutritional, economic, and health significance. This study explored the potential of machine learning (ML) for predicting tomato quality, utilizing data from 48 cultivars and 28 locations in Hungary over 5 seasons. It focused on °Brix, lycopene content, and colour (a/b ratio) using extreme gradient boosting (XGBoost) and artificial neural network (ANN) models. The results revealed that XGBoost consistently outperformed ANN, achieving high accuracy in predicting °Brix (R² = 0.98, RMSE = 0.07) and lycopene content (R² = 0.87, RMSE = 0.61), and excelling in colour prediction (a/b ratio) with a R² of 0.93 and RMSE of 0.03. ANN lagged behind particularly in colour prediction, showing a negative R² value of −0.35. Shapley additive explanation’s (SHAP) summary plot analysis indicated that both models are effective in predicting °Brix and lycopene content in tomatoes, highlighting different aspects of the data. SHAP analysis highlighted the models’ efficiency (especially in °Brix and lycopene predictions) and underscored the significant influence of cultivar choice and environmental factors like climate and soil. These findings emphasize the importance of selecting and fine-tuning the appropriate ML model for enhancing precision agriculture, underlining XGBoost’s superiority in handling complex agronomic data for quality assessment.

Landraces are considered a crucial component of biodiversity conservation, serving as a reservoir of genetic diversity. Consequently, the collection, cultivation, and detailed characterization of such landraces constitute an inherent aspect of the world’s natural resource heritage. This effort holds promise for the development of elite varieties capable of thriving amidst continuous global climate fluctuations. In this context, we conducted a comprehensive assessment of the main agronomic attributes, physico-chemical properties, and functional quality traits of the major hot pepper landraces adapted to diverse climatic conditions in Tunisia. These landraces include ‘Dhirat’, ‘Semmane’, ‘Beldi’, ‘Nabeul’, ‘Jerid’, ‘Mahdia’, ‘Cayenne’, ‘Kairouan’, and ‘Baklouti’. Most of the pepper landraces exhibited satisfactory yields, ranging from 1163.25 to 1841.67 g plant−1 in ‘Jerid’ and ‘Kairouan’, respectively, indicating robust productivity, especially under prevailing climatic changes and high temperatures during both growing cycles. The levels of antioxidants comprising capsaicinoids, carotenoids, phenolics, and tocopherols, as well as radical scavenging activity, emerged as key discriminating factors among pungent pepper landraces. Irrespective of genotype, capsaicin and dihydrocapsaicin constituted the major capsaicinoids, accounting for 44–91% of the total capsaicinoids content. Total capsaicinoids ranged from 1.81 µg g−1 fw to 193.71 µg g−1 fw, with ‘Baklouti’ and ‘Jerid’ identified as the most pungent landraces. Total carotenoids ranged from 45.94 µg g−1 fw to 174.52 µg g−1 fw, with ‘Semmane’ and ‘Jerid’ exhibiting the highest levels. Considerable variation was observed in β-carotene content, spanning from 3% to 24% of the total carotenoids. α-Tocopherol content ranged from 19.03 µg g−1 fw in ‘Kairouan’ to 30.93 µg g−1 fw in ‘Beldi’, exerting a notable influence on the overall tocopherol content. Conversely, the β- and γ-tocopherol isomers were detected at very low concentrations. The total vitamin C content ranged from 132 mg 100g−1 fw in ‘Mahdia’ to 200 mg 100 g−1 fw in ‘Nabeul’, indicating relatively low genetic variability. However, large variability was detected in total phenolics content, ranging from 168.58 mg GAE kg−1 fw in ‘Beldi’ to 302.98 mg GAE kg−1 fw in ‘Cayenne’. Landraces such as ‘Dhirat’, ‘Nabeul’, ‘Semmane’, ‘Kairouan’, ‘Cayenne’, and ‘Mahdia’ appear suitable for both fresh consumption and processing, owing to their favorable average fruit weight, soluble solids content, and bioactive content. Among the pepper landraces tested, ‘Cayenne’ achieved the highest value of radical scavenging activity in both hydrophilic and lipophilic fractions (RSAHF and RSALF), with variations ranging from 59% to 120% for RSAHF and from 4% to 63% for RSALF. This study aims to preserve and enhance the value of local genetic resources and contribute to identify desirable traits for incorporation into breeding programs to develop high-quality, high-yielding landraces and elite lines.

Potato (Solanum tuberosum L.) is a staple food widely consumed in Tunisia and a source of nutrients beneficial for human health. The tubers are, indeed, important source of vitamins, minerals, and bioactive compounds, including carotenoids, polyphenols, and flavonoids. However, data regarding the functional quality of potato varieties grown and consumed in Tunisia are very scarce. For this reason, two field trials were conducted to focus on the effect of the growing season on the functional quality of four potato genotypes (Selena, El Beidha, Naima, and CL07F172.5): a first autumnal trial in Teboulba, Monastir (September 2015-February 2016), which is the late cropping season (LCS) and a second summer cropping season (SCS) in El ksour, El Kef region at an altitude > 1000 m (July 2015-October 2015). Total carotenoids, total phenolics, and flavonoids contents, as well as the hydrophilic radical scavenging activity and lipophilic radical scavenging activity (LRSA) were determined. The obtained results confirmed the importance of potato tubers as a source of bioactive compounds. All quality traits varied significantly among varieties and cropping seasons. Tubers grown under colder weather conditions (LCS: minimum and maximum averages temperatures and relative humidity (RH) ranging between 14.25 and 22.55 degrees C and 25.46% and 83.07%, respectively) accumulated the highest total vitamin C content and exhibited the highest LRSA values. However, temperature and warmer growing conditions (SCS: minimum and maximum averages temperatures and RH ranging between 19.74 and 34.22 degrees C and 35.46% and 87.51%, respectively) probably enhanced the synthesis and accumulation of total carotenoids, total phenolics, and total flavonoids, associated with higher LRSA values.

Agriculture faces great challenges to overcome global warming and to improve system sustainability, requiring access to novel genetic diversity. So far, wild populations and local landraces remain poorly explored. This is notably the case for the two diploid species, Brassica oleracea L. (CC, 2n=2x=18) and B. rapa L. (AA, 2n=2x=20). In order to explore genetic diversity in both species, we have collected numerous populations in their center of origin, the Mediterranean basin, on a large contrasting climatic and soil gradient from northern Europe to southern sub-Saharan regions. In these areas, we also collected 14 populations belonging to five B. oleracea closely related species. Before further genetic and agronomic investigations, we controlled the absence of species misidentification using flow cytometry, sequencing of species specific chloroplast genomic region, as well as cytogenetic analyses in case of unexpected results. Looking at the 102 B. oleracea and 146 B. rapa populations showing a good germination among the 112 and 154 populations collected, seventeen populations were misidentified. The most frequent mistake was a confusion of these diploid species with B. napus . Additionally for B. rapa , 2 autotetraploid populations were observed. Habitats of the collected wild populations and landraces are described in our work. This provides a unique plant material characterization that will pave the way for further analyses investigating the genomic regions involved in climatic and microbiota adaptation. This research is supported by the H2020 Prima project ‘BrasExplor’.

Papaya fruit has a limited shelf life due to its sensitivity to decay and chilling damage during cold storage. The application of methyl jasmonate (MeJA) is known to reduce the incidence of disease and chilling injury, and to maintain the overall quality of the papaya fruit when stored at low temperature. Consequently, the effects of postharvest MeJA (1 mM) immersion on papaya fruits during low-temperature storage (10 °C ± 2 °C) for 28 days were studied. The experiment revealed that MeJA treatment significantly decreased the papaya fruit's weight loss, disease incidence, and chilling injury index. Furthermore, the accumulation of malondialdehyde and hydrogen peroxide was markedly lower after the application of MeJA. In addition, MeJA treatment exhibited significantly higher total phenols, ascorbic acid, antioxidant activity, and titratable acidity in contrast to the control. Similarly, MeJA-treated papaya fruits showed higher antioxidant enzymatic activity (superoxide dismutase, catalase, and peroxidase enzymes) with respect to the control fruits. In addition, MeJA reduced the soluble solids content, ripening index, pH, and sugar contents compared to the control fruits. Furthermore, MeJA-treated papaya fruit exhibited higher sensory and organoleptic quality attributes with respect to untreated papaya fruits. These findings suggested that postharvest MeJA application might be a useful approach for attenuating disease incidence and preventing chilling injury by enhancing antioxidant activities along with enhanced overall quality of papaya fruits during low-temperature storage.

Tomato landraces have progressively faded into obscurity, making way for new hybrids and elite tomato cultivars. This study presents a comprehensive evaluation of the agronomic attributes, physicochemical properties, and functional traits across seven cultivars, comprising two high-pigment varieties, ‘HLT−F81’ and ‘HLT−F82’, as well as five underutilized ancient-tomato genotypes considered as landraces. Most of the studied genotypes exhibited satisfactory horticultural and processing traits. The average fruit weight ranged from 73.3 g in ‘Rimone’ to 91.83 g in ‘HLT−F81’, while the soluble solids content ranged from 4.66 °Brix in ‘Justar’ to 6.08 °Brix in ‘HLT−F81’. The functional quality and the content of most antioxidants, as well as the antioxidant activity in both hydrophilic and lipophilic fractions, proved to be the most discriminating parameters among the tomato genotypes. The content of β−carotene and lycopene spanned from 2.94 mg kg−1 fw in ‘Rio Grande’ to 13.94 mg kg−1 fw in ‘HLT−F82’ and 227.8 mg kg−1 fw in ‘HLT−F81’, yielding large variations compared to ‘Rio Grande’. The total phenolic content ranged from 139.83 mg GAE kg−1 fw in ‘Rimone’ to 352.41 mg GAE kg−1 fw in ‘HLT-F81’, while the flavonoid content varied from 136.16 mg RE kg−1 fw in ‘Justar’ to 311.23 mg RE kg−1 fw in ‘HLT-F82’. The presence of tocopherol isomers was genotype-dependent, with a higher content in lines carrying the high-pigment mutations. Among the tested tomato genotypes, the high-pigment tomato line ‘HLT−F81’ achieved the highest hydrophilic and lipophilic antioxidant activity values. This study primarily focused on the recovery and valorization of tomato genetic resources and landraces. It also aimed to identify desirable horticultural (yield, low-input, and low-water demand), processing (°Brix and titratable acidity), and quality (rich antioxidant berries) traits for introgression into new tomato cultivars better suited to the evolving climate conditions of the near future.