Horticultural Crops Research Articles

A Review on Biocontrol Agents as Sustainable Approach for Crop Disease Management: Applications, Production, and Future Perspectives

Horticultural crops are vulnerable to diverse microbial infections, which have a detrimental impact on their growth, fruit quality, and productivity. Currently, chemical pesticides are widely employed to manage diseases in horticultural crops, but they have negative effects on the environment, human health, soil physiochemical properties, and biodiversity. Additionally, the use of pesticides has facilitated the development and spread of resistant pathovars, which have emerged as a serious concern in contemporary agriculture. Nonetheless, the adverse consequences of chemical pesticides on the environment and public health have worried scientists greatly in recent years, which has led to a switch to the use of biocontrol agents such as bacteria, fungi, and insects to control plant pathogens. Biocontrol agents (BCAs) form an integral part of organic farming, which is regarded as the future of sustainable agriculture. Hence, harnessing the potential of BCAs is an important viable strategy to control microbial disease in horticultural crops in a way that is also ecofriendly and can improve the soil health. Here, we discuss the role of the biological control of microbial diseases in crops. We also discuss different microbial-based BCAs such as fungal, bacterial, and viral and their role in disease management. Next, we discuss the factors that affect the performance of the BCAs under field conditions. This review also highlights the genetic engineering of BCAs to enhance their biocontrol efficiency and other growth traits. Finally, we highlight the challenges and opportunities of biocontrol-based disease management in horticulture crops and future research directions to boost their efficacy and applications.

Transcription factors LvBBX24 and LvbZIP44 coordinated anthocyanin accumulation in response to light in lily petals.

Lily (Lilium spp.), a horticultural crop serving both ornamental and edible functions, derives its coloration primarily from anthocyanins. However, limited studies have been conducted on the accumulation of anthocyanins within lilies. In this study, we cloned a light-induced transcription factor named as LvBBX24 in lilies. Through genetic and biochemical analysis, we determined that LvBBX24 could upregulate the transcription of LvMYB5 and facilitate anthocyanin synthesis. Moreover, we identified that darkness promoted the degradation of LvBBX24 protein. Through screening a yeast library, we identified LvbZIP44 acts as its interacting partner. Genetic testing confirmed that LvbZIP44 also plays a role in promoting lily anthocyanin synthesis. This indicates a potential synergistic regulatory effect between LvBBX24 and LvbZIP44. Our study indicates that LvBBX24 and LvbZIP44 cooperate to regulate anthocyanin accumulation in lily petals. These findings provide compelling evidence supporting the idea that LvBBX24 and LvbZIP44 may form a looped helix surrounding the LvMYB5 promoter region to regulate anthocyanin biosynthesis.

Role of Horticultural Crops in Food and Nutritional Security: A Review

Horticultural crops perform a very important role in both food and nutritional security more especially in developing countries. Fruit and vegetables have high content of both nutritional and health promoting compounds which consist mostly of essential vitamins, minerals and anti-oxidant that is not present in major staple food crops. Fruits and vegetables supply a large constituent of human nutrition, as they are vital sources of minerals, vitamins, nutrients, dietary fiber, ant-oxidant and phytochemicals that are easy to produce and have short production cycle. A diet rich in fruits and vegetables can help in reducing high blood pressure, lower the risk of heart disease and stroke, provide protection against most types of cancer, reduce the risk of eye and digestive problems, and have a significant effect controlling blood sugar levels which serve as appetite booster. The higher the amount of daily intake of fruits and vegetables, the lower the risk of developing cardiovascular diseases. Fruits and vegetables also contain fiber that assist in bowel movements and can relieve or prevent constipation. Eating fruits and vegetables can also keep eyes healthy and may help prevent two common eye diseases like cataracts and macular degeneration. The FAO, IFAD, UNICEF, WFP and WHO report on state of World food and nutrition security for the year 2021 painted a gloomier picture. The report estimated that between 720 and 811 million people in the world faced hunger in 2020 with close to 2.37 billion people did not have access to adequate food in 2020. Thus the need to encourage the production of horticultural crops can help in enhancing food and nutritional security since it is an enterprise that maximizes small space in terms of value and health benefits.

Advance in the Thermoinhibition of Lettuce (Lactuca sativa L.) Seed Germination.

Thermoinhibition refers to the inability of seeds to germinate when inhibited by high temperatures, but when environmental conditions return to normal, the seeds are able to germinate rapidly again, which is different from thermodormancy. Meanwhile, with global warming, the effect of the thermoinhibition phenomenon on the yield and quality of crops in agricultural production is becoming common. Lettuce, as a horticultural crop sensitive to high temperature, is particularly susceptible to the effects of thermoinhibition, resulting in yield reduction. Therefore, it is crucial to elucidate the intrinsic mechanism of action of thermoinhibition in lettuce seeds. This review mainly outlines several factors affecting thermoinhibition of lettuce seed germination, including endosperm hardening, alteration of endogenous or exogenous phytohormone concentrations, action of photosensitizing pigments, production and inhibition of metabolites, maternal effects, genetic expression, and other physical and chemical factors. Finally, we also discuss the challenges and potential of lettuce seed germination thermoinhibition research. The purpose of this study is to provide theoretical support for future research on lettuce seed germination thermoinhibition, and with the aim of revealing the mechanisms and effects behind lettuce seed thermoinhibition. This will enable the identification of more methods to alleviate seed thermoinhibition or the development of superior heat-tolerant lettuce seeds.

Evaluation of the Impact of the Ripening Stage on the Composition and Antioxidant Properties of Fruits from Organically Grown Tomato (Solanum lycopersicum L.) Spanish Varieties.

Tomato (Solanum lycopersicum L.) is a widely cultivated horticultural crop. It belongs to the Solanaceae family and is known for its high concentration of essential nutrients, including vitamins, minerals, and bioactive compounds with antioxidant properties. The Mediterranean countries, including Italy, Spain, and Greece, have a diverse range of tomato landraces. Assessing the nutritional and bioactive composition of different tomato varieties and their ripening stages is crucial to determine their suitability for the market. Therefore, the aim of this study was to investigate the effect of ripening on nutritional composition (including carotenoids and polyphenols content) and antioxidant activities of fruits of three specific tomato varieties grown in Spain: Josefina and Karelya, which are cherry-like tomatoes, and Muchamiel, a type of salad tomato. In addition to evaluating their characteristics and composition (including carotenoids and polyphenol content), the antioxidant activities of these varieties at three different ripening stages were quantified. As expected, the results reveal that, as the tomatoes matured, their antioxidant capacity increased along with higher levels of carotenoids and polyphenols. Interestingly, cherry-like tomatoes showed a higher antioxidant activity than the salad tomatoes. This investigation emphasizes the role of fruit ripening in increasing carotenoid levels, which contribute to the antioxidant activity of three tomato varieties.

Growth and Yield of Celery (Apium Graveolens L.) in Organic Cultivation on Alluvial Soil

Celery (Apium graveolens L.) is a horticultural crop that is consumable and offers numerous health benefits. The purpose of this study was to ascertain how celery growth and yield cultivated on alluvial soil were affected by the interaction between liquid organic NPK fertilizer and chicken manure. The study utilized a field experiment that was designed completely randomized comprising two factors. The first factor was the dosage of chicken manure with three levels: C1: 50 g/pot, C2: 100 g/pot, and C3: 150 g/pot. The second factor was liquid organic NPK fertilizer with three levels: L1: 1%, L2: 2%, and L3: 3%. All treatment combinations were performed in triplicates. The results indicated that the interaction between chicken manure and liquid organic NPK fertilizer significantly affected the number of tillers and dry weight of celery yield. Chicken manure as a single factor significantly influenced the number of stems and tillers. Liquid organic NPK fertilizer as a single factor significantly influenced the number of tillers, fresh weight, dry weight, and plant height. The combination of chicken manure and liquid organic NPK fertilizer (C1L3) produced the highest number of stems per clump (79.44 stems) and the highest number of tillers per clump (9.78 tillers). The combination of C2L3 yielded the highest fresh weight (184 g) and dry weight (17.33 g). Keywords: Alluvial soil, Celery, Chicken manure, Liquid organic NPK fertilizer

Optimizing the quality of horticultural crop: insights into pre-harvest practices in controlled environment agriculture.

In modern agriculture, Controlled environment agriculture (CEA) stands out as a contemporary production mode that leverages precise control over environmental conditions such as nutrient, temperature, light, and other factors to achieve efficient and high-quality agricultural production. Numerous studies have demonstrated the efficacy of manipulating these environmental factors in the short period before harvest to enhance crop yield and quality in CEA. This comprehensive review aims to provide insight into various pre-harvest practices employed in CEA, including nutrient deprivation, nutrient supply, manipulation of the light environment, and the application of exogenous hormones, with the objective of improving yield and quality in horticultural crops. Additionally, we propose an intelligent pre-harvest management system to cultivate high-quality horticultural crops. This system integrates sensor technology, data analysis, and intelligent control, enabling the customization of specific pre-harvest strategies based on producers' requirements. The envisioned pre-harvest intelligent system holds the potential to enhance crop quality, increase yield, reduce resource wastage, and offer innovative ideas and technical support for the sustainable development of CEA.

Unlocking Rapid and User-Friendly Strategies to Improve Horticultural Crop Qualities

Climatic changes and global warming affect the growth, development, and productivity of crops. In this review, we highlight the possible benefits of using innovative breeding techniques like clustered regularly interspaced short palindromic repeats (CRISPRs), exogenous phytohormone-like strigolactones (SLs), nanomaterials (NMs), and beneficial microbial endophytes to address the challenges in sustainable cultivation of horticultural crops. These applications are evaluated by examining how they affect different metabolic, morphological, and biochemical parameters in diverse crops. Endophytes are symbiotic microorganisms and can be used as nematicides for improving crop yield. With an emphasis on quality control, we examined the impacts of applying NMs, a novel family of phytohormones called SLs, and microbial endophytes on horticultural commodities. Furthermore, we reviewed the benefits of CRISPR for the editing of plant genomes, as well as how it affects gene expression and transcription factors to increase crop tolerance and yield. These innovations hold the potential to improve crop yield, quality, and resilience by acting as safe, natural components in biofertilizers and plant protection solutions. Gradually adopting these methods could decrease reliance on agrochemicals, thereby reducing their negative effects on biodiversity, soil fertility, and human health.

IN SILICO STUDIES OF IDENTIFIED COMPOUNDS FROM ETHANOLIC EXTRACT OF CELOSIA TRIGYNA AGAINST NEMATODE (Meloidogyne incognita)

Plant-parasitic nematodes (PPNs) have been found to be a major cause of considerable economic burden on the horticultural crops industry. Celosia genus have been renown to purpose antimicrobial activity. This study tends to swing the antimicrobial activity of one species of this genus i.e. Celosia trigyna against root-knot nematodes employing molecular docking methods. The identification of compounds in the leaf extract with the potential to inhibit Meloidogyne incognita was carried out in silico. Liquid Chromatography Mass Spectrometry (LCMS) was employed for analysis of the ethanolic leaf extract of this plant, it revealed the presence of cis-9-tetradecanoic acid, vitexin-glucoside, 6”-O-deoxyhexoside, gallic acid, malic acid, sinapic acid, 3-feruloylquinic acid in the extract. Site-directed multiligand docking of the identified compounds was performed on protein 2MIF of Meloidogyne incognita and employing Bifenazate and Boscalid as positive controls. The binding affinity of 3-feruloylquinic (– 4.2 kcal/mol) was significantly higher than the positive control compounds i.e. Bifenazate and Boscalid (– 4.0 kcal/mol and – 3.9 kcal/mol). The interactions of this molecule with the amino acids of the protein showed that the mechanism of its inhibitory action is similar to that of the cocrystallized ligand. This result validates that the antimicrobial activity of the ethanolic extract of the leaves of C. trigyna could be employed against root-knot nematodes for sustainable agriculture.

An integrated QTL and RNA-seq analysis revealed new petal morphology loci in Brassica napus L.

BackgroundRapeseed (Brassica napus L.) is one of the most important oil crops and a wildly cultivated horticultural crop. The petals of B. napus serve to protect the reproductive organs and attract pollinators and tourists. Understanding the genetic basis of petal morphology regulation is necessary for B. napus breeding.ResultsIn the present study, the quantitative trait locus (QTL) analysis for six B. napus petal morphology parameters in a double haploid (DH) population was conducted across six microenvironments. A total of 243 QTLs and five QTL hotspots were observed, including 232 novel QTLs and three novel QTL hotspots. The spatiotemporal transcriptomic analysis of the diversiform petals was also conducted, which indicated that the expression of plant hormone metabolic and cytoskeletal binding protein genes was variant among diversiform petals.ConclusionsThe integration of QTL and RNA-seq analysis revealed that plant hormones (including cytokinin, auxin, and gibberellin) and cytoskeleton were key regulators of the petal morphology. Subsequently, 61 high-confidence candidate genes of petal morphology regulation were identified, including Bn.SAUR10, Bn.ARF18, Bn.KIR1, Bn.NGA2, Bn.PRF1, and Bn.VLN4. The current study provided novel QTLs and candidate genes for further breeding B. napus varieties with diversiform petals.

Alternaria alternata Pathogen from Cuscuta japonica Could Serve as a Potential Bioherbicide.

Dodder (Cuscuta spp.) is a dangerous parasitic plant that causes serious damage to crop production and is challenging to eliminate. Herbicide application is a common strategy to control dodder in the field, but it is costly, ineffective, and further results in hazardous outcomes. Therefore, our study aims to identify the potential pathogens in naturally occurring dodder infections which may provide efficient biocontrol options. In this regard, the pathogens were isolated from the infected plants, their pathogenicity was validated through inoculation, and the optimal culture conditions for their growth were identified by determining the pathogenicity difference. The pathogenicity range was determined in vitro using the leaves of common horticultural plants and crops. Furthermore, a small range of horticultural plants parasitized by Cuscuta reflexa in the field were inoculated with the pathogen to determine their biosafety and biocontrol potential, and the pathogens were identified by morphological and molecular characterization. We found 7 strains that were isolated after pathogen enrichment culture. Among them, Cbp6 and Cbp7 showed the highest pathogenicity against C. reflexa. After testing the inoculation of more than 50 species of plants, only 9 species showed varying degrees of lesions on leaves, which proved the high biosafety for common plants. Field spraying of these pathogens showed a good control effect on C. reflexa after 21 days; the disease severityreached 66.0%, while its host plant did not display obvious symptoms. In conclusion, the pathogens Cbp6 and Cbp7 were identified as Alternaria alternata, and the results of this study provide a theoretical basis for the biological control of dodder.

Multistress‐tolerant Pseudomonas aeruginosa SSVP3 uses multiple strategies to control Meloidogyne incognita in tomato

AbstractTomato is the most important horticultural crop, and India is its second largest producer; however, the plant‐pathogenic nematode Meloidogyne incognita is a serious pest of tomato, causing detrimental losses in its production. This study is focused on the use of multistress‐tolerant Pseudomonas aeruginosa SSVP3 to control this devastating nematode and attempts to decipher the roles of its metabolites and volatile organic compounds (VOCs) during this interaction. The supernatant of P. aeruginosa SSVP3 caused 58% mortality in M. incognita J2 juveniles. The major nematicidal metabolites, identified using liquid chromatography‐mass spectrometry, were pyocyanin, pyoluteorin, pyochelin, benthocyanin and phenazines. The VOCs secreted by P. aeruginosa SSVP3, which were identified via gas chromatography–mass spectrometry (HS‐SPME‐GC–MS) in a mixture, caused 98% mortality in M. incognita J2 juveniles. In a pot experiment, seedling root treatment with P. aeruginosa SSVP3 activated the induced systemic response in tomato plants to M. incognita by increasing the activity of defence and antioxidant enzymes as well as the proline and phenolic contents. The malondialdehyde content in P. aeruginosa SSVP3‐treated plants decreased as compared to those in the other treatment groups. The number of galls formed and the number of endoparasitic stages of M. incognita in the untreated nematode control plants were much greater (19 and 35) than those in the P. aeruginosa SSVP3‐treated (0.33 and 1) and chemically treated groups (0.67 and 1.33). These results indicate that P. aeruginosa and its secreted metabolites and VOCs have a high potential for controlling nematodes.

Quantitative Trait Loci Mapping and Comparative Transcriptome Analysis of Fruit Weight (FW) in Watermelon (Citrullus lanatus L.).

The watermelon (Citrullus lanatus L.) holds substantial economic value as a globally cultivated horticultural crop. However, the genetic architecture of watermelon fruit weight (FW) remains poorly understood. In this study, we used sh14-11 with small fruit and N14 with big fruit to construct 100 recombinant inbred lines (RILs). Based on whole-genome resequencing (WGR), 218,127 single nucleotide polymorphisms (SNPs) were detected to construct a high-quality genetic map. After quantitative trait loci (QTL) mapping, a candidate interval of 31-38 Mb on chromosome 2 was identified for FW. Simultaneously, the bulked segregant analysis (BSA) in the F2 population corroborated the identification of the same interval, encompassing the homologous gene linked to the known FW-related gene fas. Additionally, RNA-seq was carried out across 11 tissues from sh14-11 and N14, revealing expression profiles that identified 1695 new genes and corrected the annotation of 2941 genes. Subsequent differential expression analysis unveiled 8969 differentially expressed genes (DEGs), with 354 of these genes exhibiting significant differences across four key developmental stages. The integration of QTL mapping and differential expression analysis facilitated the identification of 14 FW-related genes, including annotated TGA and NAC transcription factors implicated in fruit development. This combined approach offers valuable insights into the genetic basis of FW, providing crucial resources for enhancing watermelon cultivation.

Comparative transcriptomics analysis of tolerant and sensitive genotypes reveals genes involved in the response to cold stress in bitter gourd (Momordica charantia L.)

Bitter gourd is an economically important horticultural crop for its edible and medicinal value. However, the regulatory mechanisms of bitter gourd in response to cold stress are still poorly elucidated. In this study, phytohormone determination and comparative transcriptome analyses in XY (cold-tolerant) and QF (cold-sensitive) after low temperature treatment were conducted. Under cold stress, the endogenous contents of abscisic acid (ABA), jasmonic acid (JA) and salicylic acid (SA) in XY were significantly increased at 24 h after treatment (HAT), indicating that ABA, JA and SA might function in regulating cold resistance. RNA-seq results revealed that more differentially expressed genes were identified at 6 HAT in QF and 24 HAT in XY, respectively. KEGG analysis suggested that the plant hormone signal transduction pathway was significantly enriched in both genotypes at all the time points. In addition, transcription factors showing different expression patterns between XY and QF were identified, including CBF3, ERF2, NAC90, WRKY51 and WRKY70. Weighted gene co-expression network analysis suggested MARK1, ERF17, UGT74E2, GH3.1 and PPR as hub genes. These results will deepen the understanding of molecular mechanism of bitter gourd in response to cold stress and the identified genes may help to facilitate the genetic improvement of cold-resistant cultivars.

CO2 Laser-labeling on Fresh Produce: Evaluating Postharvest Quality, Microbial Safety, and Economic Analysis

Fresh produce is traditionally labeled with plastic price lookup (PLU) stickers that are attached to the produce surface using edible glue. However, both the stickers and glue are environmental contaminants, and the stickers can still easily detach from the produce surface during handling and disrupt traceability. An alternative method of labeling, the CO2 laser-labeling technology (LLT), has been gaining attention in recent years. However, engraving Quick Response (QR) code using LLT is unique, and the performance of this technology varies from produce item to produce item, and information on its effects on postharvest quality, microbial safety, and economic feasibility has not been reported. The objectives of this study were to investigate the effect of laser-labeling technology on (1) postharvest quality, (2) microbial safety, and (3) economic analysis of this technology. Three horticultural crops, ‘Red Delicious’ apple (Malus pumila), green bell pepper (Capsicum annuum), and cucumber (Cucumis sativus) were procured from a local grocery store. Each produce was engraved with a Quick Response (QR) code or 6-digit alphanumerical (text) code using the commercially available Trotec Speedy 300 CO2 laser engraver, followed by the application of edible wax. Fresh weight loss for laser-printed produce was higher compared to controls, but no difference in visual quality ratings was observed. The laser-labeled produce was assessed for microbial contamination by artificially inoculating rifampicin-resistant Escherichia coli (E. coli) log10 6 CFU/mL to the labeled fruit. The results showed that the population of rifampicin-resistant E. coli was statistically higher in all three products labeled with text code compared to the nontreated controls. The QR-coded treatments were similar to the controls. The wax application did not affect the microbial attachment on the laser-labeled produce. The CO2 laser labeling technology has the potential for industrial application.

Contribution of the postharvest period to soil N2O emissions from arable Mediterranean crops

Soil nitrous oxide (N2O) emissions are a relevant contributor to the global warming potential of Mediterranean agro-ecosystems and therefore should be accurately quantified. Here, we investigated the quantitative relevance of considering postharvest N2O measurements when calculating annual soil N2O emissions from herbaceous crops (excluding rice). Data from 25 studies conducted in Mediterranean climates were compiled from a variety of crops and cropping systems, soil types, tillage practices, and nitrogen (N) fertilizer management practices. The differences between cumulative N2O emissions in the cropping period (preharvest emissions) and in the postharvest period were evaluated through a meta-analysis, as were the maximum N2O peaks in both periods and the resultant N2O emission factors (EFs). The relative contribution of the postharvest period to total cumulative N2O emissions was a mean 26%, but showed high variability. The average N2O EFs in the field experiments included in this study were 0.21% and 0.27% when not considering and when considering the postharvest period, respectively. The relative and absolute contribution of postharvest emissions was significantly greater for winter cereals than for either horticultural crops or maize. The maximum preharvest fluxes were higher than the maximum postharvest fluxes in 72% of the observations, but notable postharvest N2O peaks after soil rewetting were obtained in some studies. On average, postharvest emissions in nonfertilized plots were similar to those in fertilized winter crops. Other factors such as N source (greater relevance for organic fertilizers, particularly in summer crops), N rate, tillage intensity and soil texture significantly affected the amount of postharvest emissions. Taking measurements during the postharvest period in Mediterranean cropping systems are encouraged in studies that include winter crops, use of organic fertilizers or have unbalanced N rates. Our results may contribute to improving N2O measurement protocols and to re-evaluating N2O EFs in Mediterranean and semiarid areas.

Biochemical versus stomatal acclimation of dynamic photosynthetic gas exchange to elevated CO2 in three horticultural species with contrasting stomatal morphology.

Understanding photosynthetic acclimation to elevated CO2 (eCO2) is important for predicting plant physiology and optimizing management decisions under global climate change, but is underexplored in important horticultural crops. We grew three crops differing in stomatal density-namely chrysanthemum, tomato, and cucumber-at near-ambient CO2 (450 μmol mol-1) and eCO2 (900 μmol mol-1) for 6 weeks. Steady-state and dynamic photosynthetic and stomatal conductance (gs) responses were quantified by gas exchange measurements. Opening and closure of individual stomata were imaged in situ, using a novel custom-made microscope. The three crop species acclimated to eCO2 with very different strategies: Cucumber (with the highest stomatal density) acclimated to eCO2 mostly via dynamic gs responses, whereas chrysanthemum (with the lowest stomatal density) acclimated to eCO2 mostly via photosynthetic biochemistry. Tomato exhibited acclimation in both photosynthesis and gs kinetics. eCO2 acclimation in individual stomatal pore movement increased rates of pore aperture changes in chrysanthemum, but such acclimation responses resulted in no changes in gs responses. Although eCO2 acclimation occurred in all three crops, photosynthesis under fluctuating irradiance was hardly affected. Our study stresses the importance of quantifying eCO2 acclimatory responses at different integration levels to understand photosynthetic performance under future eCO2 environments.

Evaluation of endophytic colonization and establishment of entomopathogenic fungi against Tuta absoluta (Lepidoptera: Gelechiidae) in tomato plants.

The tomato, Solanum lycopersicum L., is one of the most important horticultural crops that can be consumed fresh or after being processed worldwide. The tomato leaf miner (Tuta absoluta) is one of the most devastating pest to tomato plants due to its mine-feeding nature in the mesophyll tissue of the plant. Fungal entomopathogens can exist naturally in plants as an asymptote. This study aimed to detect the endophytic colonization of Beauveria bassiana and Metarhizium robertsii within tomato plants via artificial inoculation and their virulence effects on Tuta absoluta. Isolates with the highest percent germination and virulence against T. absoluta were selected for endophytic evaluation within tomato plants by different artificial inoculation techniques. This study revealed that, isolates with the highest percent germination and virulent to Tuta absoluta had the potential to colonize tomato plants. The result showed that, the maximum mortality rate (97.5%) of Tuta absoluta larvae was achieved by Metarhizium robertsii isolate K-61 at a concentration of 1x10 8conidial/ml at 7 days post inoculated. However, the highest cumulative mortality (100%) was recorded by Beauveria bassiana isolate APPRC-27 at 10 days post inoculated through the direct contact method. The highest endophytic colonization was registered by isolate APPRC-27 (76.67%) at 7 days post-inoculated using the leaf spray technique, but it declined to 11.67% after 28 days of inoculated. In the case of the seedling inoculation technique, the highest endophytic colonization was obtained in the root tissues of tomatoes at 28 days of inoculated by isolate K-61. This study revealed that the leaf spray inoculation technique was the most effective method, followed by seedling inoculation, for the deployment of Beauveria bassiana and Metarhizium robertsii endophytes in tomato plant tissues. Therefore, virulent Beauveria bassiana and Metarhizium robertsii, are promising bioagents for the control of Tuta absoluta if deployed as endophytes.

Identifying the Traditional and Existing Tree–Crop Combination of Agroforestry System in Southern Part of Chhattisgarh, India

The present study was conducted in Bastar district of Chhattisgarh to identify the traditional and existing agroforestry practices used by farmers. The data were collected through survey of field visits and filled out of pre-prepared questionnaires in four blocks of Bastar district, namely Jagdalpur, Bastar, Tokapal and Bakawand. The survey revealed six different types of agroforestry system practices i.e., agrisilvihorticulture, agrisilviculture, silvihorticulture, agrisilvipastoral, silvihortipastoral, and agrisilvihortipastoral. Among these, 67% of farmers were practiced agrisilvihorticulture-type agroforestry systems. Farmers in Bastar were found to use 29 different tree crops, 17 horticultural crops, 20 vegetable crops, and 11 agricultural crops in their fields.

Transcription factor MdbZIP44 targets the promoter of MdPPO2 to regulate browning in Malus domestica Borkh.

Apple (Malus domestica Borkh.) is among the most widely planted and economically valuable horticultural crops globally. Over time, the apple fruit's cut surface undergoes browning, and the degree of browning varies among different apple varieties. Browning not only affects the appearance of fruits but also adversely affects their taste and flavor. In the present study, we observed browning in different apple varieties over time and analyzed the expression of genes in the polyphenol oxidase gene family. The results indicated a strong correlation between the browning degree of the fruit and the relative expression of the polyphenol oxidase gene MdPPO2. With the MdPPO2 promoter as bait, the basic leucine zipper (bZIP) transcription factor MdbZIP44 was identified using the yeast single-hybrid screening method. Further investigation revealed that the overexpression of MdbZIP44 in ‘Orin’ callus could enhance the expression of MdPPO2 and promote browning of the callus. However, knocking out MdbZIP44 resulted in a callus with no apparent browning phenotype. In addition, our results confirmed the interaction between MdbZIP44 and MdbZIP11. In conclusion, the results indicated that MdbZIP44 can induce apple fruit browning by activating the MdPPO2 promoter. The results provide a theoretical basis for further clarifying the browning mechanism of apple fruit.