Effects of Oligochitosan on Postharvest Alternaria Rot, Storage Quality, and Defense Responses in Chinese Jujube (Zizyphus jujuba Mill. cv. Dongzao) Fruit

2011 ◽  
Vol 74 (5) ◽  
pp. 783-788 ◽  
Author(s):  
JIAQI YAN ◽  
JIAN LI ◽  
HONGWEI ZHAO ◽  
NI CHEN ◽  
JIANKANG CAO ◽  
...  

Effects of oligochitosan (OCH) on postharvest rot caused by Alternaria alternata in Chinese jujube (Zizyphus jujuba Mill. cv. Dongzao) fruit were investigated. An in vitro test indicated that mycelial growth of A. alternata was strongly suppressed by OCH at 0.5, 1, 2, 5, 10, 15, or 20 g/liter. The half-inhibition concentration of OCH against this fungus was 0.76 and 1.69 g/liter on days 4 and 6 of incubation, respectively. Lesion area and disease incidence in the jujube fruit inoculated with A. alternata were remarkably reduced by the OCH treatments at concentrations higher than 1 g/liter, but 5 g/liter OCH was considered the optimal treatment for inhibiting disease development. OCH also significantly reduced postharvest natural decay, promoted fruit firmness, delayed decline in soluble solids and loss of ascorbic acid, and increased total phenolic compounds during storage at 0°C and 85 to 95% relative humidity. Biochemical evaluations revealed that the activities of the main defense-related enzymes in the jujube fruit, including phenylalanine ammonia–lyase, peroxidase, chitinase, and β-1,3-glucanase, were significantly enhanced (P < 0.05) by OCH treatment. OCH increased superoxide dismutase activity but decreased catalase activity and, consequently, elevated hydrogen peroxide levels in the fruit. These results suggest that OCH might trigger several defense mechanisms in the jujube fruit for disease control in addition to its direct antifungal activity. OCH could be a viable alternative to conventional control of postharvest diseases of horticultural products.

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 803
Author(s):  
Elia Nora Aquino-Bolaños ◽  
Alma Karina Garzón-García ◽  
Jimena Esther Alba-Jiménez ◽  
José Luis Chávez-Servia ◽  
Araceli Minerva Vera-Guzmán ◽  
...  

The green bean is an important crop worldwide, because it is rich in protein, dietary fiber, vitamins, and minerals, as well as bioactive compounds that provide it with important functional properties; however, the composition of many landraces is still unknown. The purpose of this project was to characterize Phaselus vulgaris and coccineus L. landrace green beans on pH, titratable acidity, total soluble solids, total sugars, color parameters, total phenols, monomeric anthocyanins, and in vitro antioxidant activity (DPPH and FRAP). Regarding the content of total sugars, differences were registered between both species, as opposed to results observed in total soluble solids. Color parameters showed higher reddish tones for P. vulgaris landraces, though P. coccineus had a higher total phenolic content, especially the reddish landraces, which correlated directly to a higher antioxidant activity by DPPH and FRAP. In the protein content, the species P. vulgaris registered the highest content. These results could contribute to a greater use and even promote the genetic improvement of the outstanding pods that serve as one of the main food products in rural regions for higher benefits.


2012 ◽  
Vol 15 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Paula Judith Perez Espitia ◽  
Nilda de Fátima Ferreira Soares ◽  
Laura Costa Moreira Botti ◽  
Nathália Ramos de Melo ◽  
Olinto Liparini Pereira ◽  
...  

Rot and damage caused by post-harvest phytopathogenic fungi affect fruit quality. Essential oils (EO) are considered as an alternative to fungicides. Postharvest diseases of fruits may also be controlled by the bagging approach and the use of antimicrobial packaging. Based on the beneficial properties of EO and the concepts of bagging and antimicrobial packaging, this study aimed to develop sachets containing EO to be used as part of an antimicrobial packaging system. The activities of oregano, cinnamon and lemon grass EO were evaluated testing the sachets in vitro against the phytopathogenic fungi Alternaria alternata, Fusarium semitectum, Lasiodiplodia theobromae and Rhizopus stolonifer. The effects of the sachets on the microbiological and physicochemical parameters of post-harvest papaya were also evaluated. Both pure and sachet-incorporated EO showed antifungal activity in vitro against all tested fungi. For papaya, sachets containing cinnamon, oregano and lemon grass showed a significant reduction in the growth of mesophilic aerobic bacteria, yeasts and mould, with the cinnamon sachet causing the greatest reduction in microorganisms at the end of the storage time. Physicochemical parameters of papaya, such as weight loss, colour, firmness, total soluble solids/titratable acidity ratio and pH were not significantly altered by the presence of EO sachets, thus not affecting the natural ripening process of the papaya.


2017 ◽  
Vol 9 (2) ◽  
pp. 162 ◽  
Author(s):  
Juliane Mendes Lemos Blainski ◽  
Argus Cezar da Rocha Neto ◽  
Caroline Luiz ◽  
Márcio José Rossi ◽  
Robson Marcelo Di Piero

Lactic acid bacteria produce several exopolysaccharides (EPS) that may have antimicrobial action and/or induce defense responses in plants. This work aims to evaluate the potential of EPS produced by Lactobacillus plantarum in the protection of tomato plants against bacterial spot caused by Xanthomonas gardneri, as well as to predict the possible mechanisms of action. The EPS were characterized through FTIR and applied at 0; 0.5; 1.5 and 3.0 mg mL-1 in tomato plants with five expanded leaves, followed by the pathogen inoculation after 3 or 7 days. Antimicrobial activity of the biopolymer (1.5 or 10.0 mg mL-1) was evaluated in bioassay when EPS was incorporated into culture medium or embedded in antibiogram disk. The defense mechanisms i.e., total phenolic compounds and flavonoids content, phenylalanine ammonia-lyase (PAL), glutathione reductase (GR) and lipoxygenase (LOX) activities, were measured in tomato plants treated with EPS (1.5 mg mL-1), inoculated or not with X. gardneri. EPS reduced bacterial spot symptoms by up to 72.0% compared to the control. There were no direct effects of EPS on the in vitro growth of X. gardneri. The spectrophotometric profile, ascorbic and ellagic acid concentrations were change in tomato plants after EPS application, in plants challenged with the pathogen. Increases in PAL, GR and LOX activities were observed in plants treated with EPS. Thus, the application of L. plantarum exopolysaccharides can be considered as an effective alternative for controlling bacterial spot in tomato plants. This paper also discusses how these exopolysaccharides reduced the severity of the disease.


Author(s):  
Deepak K. Koche ◽  
Arvind D. Chaudhary

Most cultivars of Vigna radiata (L) Wilczek grown in Indian subcontinent are susceptible to various biotic and abiotic stresses. Cercospora leaf spot (CLS) is a major biotic stress resulting in poor yield of this crop. Therefore, it is essential to investigate resistance status of different cultivars to CLS and develop effective strategy. Present investigation was focused on the role of biochemical compounds in resistance response of this crop to CLS in naturally grown population and after artificial induction with pathogen derived elicitor. The defense responses in vivo and in vitro were analyzed in the form of phytoalexin genestein, PAL and PR- proteins in their leaves. PR-proteins, PAL and genestein were assayed employing established protocols. In naturally grown population, four cultivars- Kopergaon, TARM-1, TARM-2 and TARM-18 showed lesser accumulation of genestein and lower level of PAL and PR- proteins. However, Pant M-3, ML-1037 and ML-936 showed resistant interaction with very high accumulation of genestein, PAL and PR proteins. Similar trends of accumulation of these biochemicals were observed in in vitro condition after elicitation with pathogen derived elicitor. The correlation study showed that the cultivars with lower defense related expression showed high disease incidence (51-61%) and with higher defense related expression were with less than 5% CLS incidence. It could be stated that PR-proteins, PAL and genestein has prominent role in defense mechanism of mungbean against CLS  as biochemical markers and further their utility in early screening for disease resistance of crop plants could be explored.


2016 ◽  
Vol 46 (3) ◽  
pp. 245-253 ◽  
Author(s):  
Elizandra Pivotto Pavanello ◽  
Auri Brackmann ◽  
Ivan Francisco Dressler da Costa ◽  
Vanderlei Both ◽  
Vagner Ludwig

ABSTRACT Peach brown rot, caused by the Monilinia fructicola fungus, is the main disease affecting peach crops, and it is mainly controlled via frequent fungicide applications. This study aimed at searching for alternatives to the intensive use of chemicals, evaluating silicon doses to control pre and postharvest peach brown rot and their influence on maturation parameters and fruit quality. Treatments consisted of control (water) and sodium metasilicate doses (2 g L-1, 4 g L-1, 6 g L-1, 8 g L-1 and 10 g L-1 of water). The following assessments were made: spore germination and in vitro mycelial growth, brown rot incidence, soluble solids, titratable acidity, flesh firmness, total polyphenol content and fruit ethylene production and respiration rate. The 2 g L-1 dose reduced spore germination by 95 %. Doses of 6 g L-1 and 8 g L-1 satisfactorily reduced the disease incidence in the field, with 77 % and 89.2 % control, respectively. Sodium metasilicate resulted in the maintenance of great fruit firmness, reduced respiration and ethylene production and increased total polyphenol synthesis, but it did not influence the titratable acidity or soluble solids. Applying 6 g L-1 may potentially control pre and postharvest peach brown rot, besides increasing the total polyphenol synthesis and maintaining a higher flesh firmness.


2013 ◽  
Vol 8 (1) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Agnieszka Kicel ◽  
Maria Wolbiś

In order to facilitate the quality control of Trifolium repens flowers and leaves, a RP-HPLC method with UV detection was developed for the simultaneous quantitative determination of flavonols and isoflavones. The total flavonoid and phenolic (TPC) contents were determined spectrophotometrically in a visible part of the light spectrum at 425 and 760 nm, respectively. Additionally, evaluation of the antioxidant properties of the plant materials was performed using the DPPH in vitro test. The results showed that the flowers are the richest source of phenolics ranging from 28.7 to 38.8 mg GAE/g, and flavonoids, calculated for hyperoside, up to 20 mg HP/g, which hydrolyzed mainly to flavonols (the quercetin level greater than 6 mg/g). T. repens is poor in isoflavones; similar quantities of ca. 0.2 mg/g were detected in the flowers and leaves. The flower and leaf extracts showed antioxidant activity towards DPPH with EC50 values ranging from 72.3 to 179.3 μg/mL. Significant linear correlations were found between antioxidant potentials of the studied plant materials and total phenolic and flavonoid contents determined by HPLC and spectrophotometric methods ( R2 in the range of 0.97 - 0.99).


Author(s):  
MI Hossain ◽  
MR Islam ◽  
MN Uddin ◽  
SM Arifuzzaman ◽  
GN Hasan

The experiments were conducted at Laboratory of the Department of Plant Pathology and in the farm of Sher-e-Bangla Agricultural University, Dhaka-1207, Bangladesh during Rabi season of the year 2007-2008. Four fungicides viz. Bavistin 50 WP (Carbendazim), Tilt 250 EC (Propiconazole), Cupravit 50 WP (Copperoxychloride) and Dithane M-45 (Mancozeb) and micronutrients (Gypsum, ZnO and Boric acid) were evaluated against Phomopsis vexans causing Phomopsis blight and fruit rot of eggplant. The fungicides and micronutrients either applied individually or in combination showed significant effect in terms of per cent leaf infection, fruit infection, leaf area diseased and fruit area diseased in comparison to control. Effect of each fungicide applied in combination with micronutrients always showed better performance in reducing disease incidence and disease severity than the fungicides applied alone. Among the fungicides, Bavistin 50 WP (0.1%) proved to be effective arresting the spore germination and mycelia growth of Phomopsis vexans assayed in in vitro test. Reduction of leaf area diseased caused by Bavistin 50 WP (0.1%) in combination with micronutrients were 58.17, 67.37, 78.41 and 85.25%, respectively at preflowering, post-flowering, fruiting and fruit ripening stages while Bavistin 50 WP (0.1%) alone reduced by 52.22, 58.67, 74.19 and 83.09%, respectively at those stages. Similarly reduction of fruit area diseased caused by Bavistin 50 WP (0.1%) in combination with micronutrients were 57.93 and 79.79%, respectively at fruiting and fruit ripening stages while Bavistin 50WP (0.1%) alone reduced by 56.93 and 76.14%, respectively at those stages. Micronutrients had little effect against the disease but significantly better than control.Int. J. Agril. Res. Innov. & Tech. 3 (1): 66-72, June, 2013 DOI: http://dx.doi.org/10.3329/ijarit.v3i1.16095


2020 ◽  
Vol 10 (17) ◽  
pp. 6007 ◽  
Author(s):  
Yung-Sheng Lin ◽  
Wen-Shin Lin ◽  
Jing-Wen Tung ◽  
Ya-Chih Cheng ◽  
Min-Yun Chang ◽  
...  

In this study, the effects of different fruit parts and extraction conditions on the antioxidant properties of jujube (Ziziphus jujuba Mill.) fruit were investigated. Five in vitro antioxidant models and statistical analyses were performed. The results revealed that jujube peel with pulp (peel pulp) exhibited better antioxidant capacity than did seeds. Overall, jujube peel pulp extracted using 50% ethanol at 60 °C exhibited the best antioxidant capacity in terms of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (0.3 ± 0 mg/mL), 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity (0.5 ± 0 mg/mL), total phenolic content (38.3 ± 0.4 mg gallic acid equivalent per gram dry weight), total flavonoid content (43.8 ± 0.2 mg quercetin equivalent per gram dry weight), and reducing power (41.9 ± 2.2 mg ascorbic acid equivalent per gram dry weight). The results indicated that jujube peel pulp is a more potential natural antioxidant than seeds.


2021 ◽  
Vol 1033 ◽  
pp. 87-92
Author(s):  
Lilis Kistriyani ◽  
Lutfi Kurniawan ◽  
Fadhli Syaputra ◽  
Achmad Chafidz

The purpose of this study was to determine and compare the effect of oven drying and spray drying treatments on the encapsulation of anthocyanin, flavonoid and phenolic extracted from watermelon rind. The analysis done in this work were as follow: total anthocyanin (TA), total flavonoid (TF) and total phenolic (TPC) content in the supernatant, yield of nanocapsule, Particle Size Analysis, and In Vitro test (test for flavonoid and phenolic release) in the supernatant food. The analysis results showed that the total anthocyanin content in watermelon rind with a spray drying treatment was 0.1113 mg/L, total flavonoid was 0.6159 g/mL, and total phenolic was 0.3410 g/mL. While using the oven, the anthocyanin content was 0.0891 mg/L, total flavonoid was 1.4590 g/mL, and total phenolic was 1.1349 g/mL. As noticed, the total content of anthocyanin resulted by using a spray dryer was greater than by using an oven. However, the total flavonoid and total phenolic resulted by using a spray dryer was smaller than by using an oven. During In Vitro analysis, the results of the release of flavonoid and phenolic resulted by using an oven into the distilled water were much larger and unstable than by using a spray dryer. This is likely because chitosan-Na (TPP) bonds are weak. Additionally, the yield of capsule on the use of spray dryer was 0.6, higher than the use of an oven, which was 0.48. While, the average particle size in the use of a spray dryer was 2.296 μm, smaller than the use of an oven, which was 61.998 μm.


Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 497-501 ◽  
Author(s):  
Guo Zheng Qin ◽  
Shi Ping Tian

An antagonistic yeast, Cryptococcus laurentii, alone or in combination with a low dose of imazalil (25 μg a.i./ml) or kresoxim-methyl (50 μg a.i./ml), was investigated for its ability to control Alternaria alternata and Monilinia fructicola on jujube fruit under different storage conditions. Biocontrol activity of C. laurentii against A. alternata and M. fructicola at 20°C was enhanced significantly by combination with either fungicide. An integrated strategy for control of A. alternata and M. fructicola was developed that included a combination of C. laurentii, a low dose of fungicide, and controlled-atmosphere (CA) storage. Fruit treated with C. laurentii plus imazalil at 25 μg a.i./ml or kresoxim-methyl at 50 μg a.i./ml and stored in CA storage with 10% O2 + 0% CO2 at 0°C showed a lower disease incidence caused by both pathogens than fruit stored in air at 0°C. Application of imazalil (25 μg a.i./ml) or kresoxim-methyl (50 μg a.i./ml) did not inhibit the growth of C. laurentii in wounds of jujube fruit stored in air at 20 and 0°C or in CA at 0°C. The yeast grew rapidly in the wounds of jujube fruit under all storage conditions. The ability of C. laurentii to effectively control postharvest diseases of jujube fruit, the resistance of C. laurentii to low rates of fungicides, and the adaptability of this yeast to CA storage indicate that C. laurentii has great commercial potential as a biological control product.


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