Suppress Anthracnose Disease Research Articles

Effect of chitosan-tripolyphosphate to suppress anthracnose (Colletotrichum spp.) in post-harvest chili

Anthracnose disease (Colletotrichum spp.) in chili can lead to low fruit quantity and quality from planting to the postharvest stage. The environmentally friendly management using chitosan (CS) is expected to suppress anthracnose disease and increase the shelf-life of chili. This study aimed to determine the effect of the chitosan-tripolyphosphate (CS-TPP) to suppress anthracnose on chili during postharvest storage through in-vitro and in-vivo assays. In the in-vitro assay, CS-TPP solution with a ratio of [5:2] and [3:1] was applied into a warm Potato Dextrose Agar (PDA) medium. It was grown by Colletotrichum pathogen, while on in vivo assay, CS-TPP was applied to chili fruit before being inoculated by the pathogen. A control treatment was prepared without CS-TPP application. Results revealed that the CS-TPP ratios affected the growth of Colletotrichum spp. at the in-vitro assay. The CS-TPP [5:2] ratio was more effective than CS-TPP [3:1] in reducing the growth of Colletotrichum spp. with the fungal inhibition of 62,65% and 55,56%, respectively, compared to the control treatment. Moreover, it also showed anthracnose disease suppression on chili fruit of 51%, and 29%, respectively, compared to control treatment at in-vivo assay. This study showed the potential use of CS-TPP as a coating application for anthracnose disease management on storage chili, however further study such as viability and longevity of formula need to be done.

Consortia of endophytic bacteria for controlling Colletotrichum gloeosporiodes causing anthracnose disease in chili plant

Abstract. Nurbailis, Yanti Y, Resti Z, Djamaan A, Rahayu SD. 2023. Consortia of endophytic bacteria for controlling Colletotrichum gloeosporiodes causing anthracnose disease in chili plant. Biodiversitas 24: 3503-3511. Anthracnose disease caused by Colletotrichum gloeosporioides is the main disease in chili plants, which reduces yields by up to 90%. Using a consortium of endophytic bacteria is an alternative way to control the disease at a low cost and is environmentally friendly. The aim of the study was to obtain the best consortium of endophytic bacteria to control anthracnose caused by C. gloeosporioides and improve the growth and yield of chili plants. This research was arranged in an experimental method consisting of two stages, namely (i) compatibility test between endophytic bacterial consisting of 28 species, and (ii) test of the endophytic bacterial consortium ability to control anthracnose in chili using a Completely Randomized Design (CRD) with 14 treatments and provided with 3 replications. All treatments of endophytic bacterial consortium showed the potential to suppress anthracnose disease caused by C. gloeosporioides and improve the growth and yield of chili plants. The best bacterial consortium treatment in suppressing the development of anthracnose disease by C. gloeosporioides and increasing the growth and yield of chili plants was the consortium B. cereus SNE 2.2 + B. cereus TLE 1.1 with dis-ease severity of 0.00%, plant height of 58.33 cm and fruit weight of 208.97 g.

Pengaruh Limbah Padat Kelapa Sawit untuk Penyakit Antraknosa (Colletotrichum spp.) Pada Tanaman Cabai Rawit

Chili plants are plants that are very commonly cultivated in Indonesia for consumption. Chili plant production has increased every year. With this, efforts to increase the production of chili plants continue to be increased. One of the chili plant problems that can affect chili production is anthracnose disease caused by a fungus (Colletotrichum spp.). This study aims to determine the effect of liquid smoke from palm oil solid waste to suppress anthracnose disease in cayenne pepper plants. This study uses palm oil solid waste as the main ingredient for making liquid smoke. This study used a one-factor Completely Randomized Design (CRD). The results showed that the treatment had no significant effect on disease incidence, significantly affected plant height in the TF (fiber) and TJ (empty bunch) treatments.

Pengaruh Beberapa Pestisida Nabati Dalam Menekan Kejadian Penyakit Antraknosa Pada Cabai Rawit Hiyung Di Desa Tajau Landung

Research on the use of several botanical pesticides from karamunting leaves, kramai leaves and rhizomes (turmeric, sand ginger and galangal) on cayenne pepper hiyung in Tajau Landung Village. Cayenne pepper (Capsicum frustescens L.) is a typical commodity of South Kalimantan, and one of the local varieties is known as hiyung chili. One of the causes of the decrease in chili production both in quality and quantity is anthracnose disease caused by Colletotrichum sp. This study aims to determine the effect of several vegetable pesticides in suppressing the incidence of anthracnose disease in Hiyung cayenne pepper in the swamp land of Tajau Landung Village. A total of 20 separate experiments were carried out, all of which followed a Completely Randomized Design (CRD) with 4 treatments and 5 replications each. The growth parameters measured were chili plant height, number of chilies, chili fruit weight and the incidence of anthracnose disease in chilies. The results of this study were the application of biologicalpesticides, karamunting and rhizomes (turmeric, sand ginger and galangal) were able to suppress anthracnose disease compared to the control treatment. However, in each treatment, karamunting and rhizomes (turmeric, kencur and galangal) had the same effect in reducing the spread of anthracnose in Hiyung cayenne pepper as grown in Tajau Landung.

Kemampuan Trichoderma viride Isolat PP2 dalam Mengendalikan Colletotrichum gloeosporioides pada Tanaman Cabai (Capsicum annuum Linnaeus) secara In-Planta

The culture filtrate is a secondary metabolite produced from the multiplication of fungi in a liquid medium during the incubation period, separated between the fungal cell and their supernatants. Trichoderma viride culture filtrate testing has been widely carried out and used as a biocontrol agent. This study aimed to determine the ability of Trichoderma viride PP2 culture filtrate concentration in suppressing anthracnose disease caused by C. gloeosporioides on the red chili pepper. The study was conducted with a randomized block design (RBD) consisting of 5 treatments and five replications. The treatments were the concentration of T. viride PP2 culture filtrate, i.e., 0% (control), 25%, 50%, 75% and 100%. Parameters observed were incubation period, percentage of infected, and infected intensity. The results showed that the application of filtrate of T. viride isolate PP2 with different concentrations has not been able to suppress the development of anthracnose disease caused by C. gloeosporioides in-planta. It is necessary to conduct further research on the effect of temperature and time application on suppressing the filtrate of T. viride isolate PP2.

Uji Cara Aplikasi PGPR dalam Menekan Kejadian Penyakit Antraknosa pada Tanaman Cabai Hiyung di Lahan Rawa

Chili Hiyung is a local chili variety typical of South Kalimantan. At this time began to be exposed to a lot of anthracnose disease. Control using pesticides needs to be avoided by finding more convenient control methods. Area-friendly disease control includes using PGPR (Plant Growth Promoting Rhizobacteria). The use of PGPR for chili plants in the swamp land of Hiyung village has not been studied, meanwhile its potential has been tested on several other plants. This research aims to identify the effect of PGPR in suppressing anthracnose disease in Chili Hiyung in the swamp land of Hiyung Village. The design used was a single aspect Completely Randomized Design (CRD) based on 4 (four) treatments, namely the leak, spray, or spray and leak methods. The results of the research show that the PGPR application does not affect the incidence of anthracnose disease in Hiyung chili plants in Hiyung village. But the PGPR application can increase plant size and fruit weight per branch.

Potensi Isolat Kamir Filosfer Buah Cabai sebagai Antagonis Terhadap Patogen Antraknosa

Anthracnose disease in chili is caused by C. acutatum. This disease can cause a decrease in quality and production of chili pepper. The use of biological control agents can be an alternative in controlling of C. acutatum. The use of biological agents is more environmentally friendly and reduces the negative effects of synthetic pesticides. This study aims to obtain yeast isolates from the phyllosphere that have the potential to suppress anthracnose disease. The research was carried out at the Laboratory of Diseases at the Faculty of Agriculture, Tanjungpura University, Pontianak from July to October 2019. Yeast isolation used a pouring plate method on the media YGCA after the yeast on the fruit surface was enriched in liquid media YGC during 24 hours. Yeast antagonism test against C. acutatum using the dual culture method, conidia viability, and the ability of pathogens to infect fruit. The results of the isolation obtained 8 yeast isolates in healthy chili of Gada variety. Antagonism test obtained 3 yeast isolates with the highest inhibitory to C. acutatum growth, isolates K2, K3 and K5. Inhibition is greater than 50%. Based on the severity index of the disease in the hypovirulent test, the three yeast isolates were not pathogenic. In the in vivo test with the immersion method, both using yeast cells and filtrate showed that yeast cells could inhibit the growth of C. acutatum infection ability better than yeast filtrate. All yeast isolates can suppress the growth of C. acutatum with a different percentage of disease.

Effect of UV-C Hormesis in Regulating Anthracnose Disease and Postharvest Quality of Tomato

Purpose : Anthracnose disease caused by Colletotrichum coccodes is a significant postharvest disease in tomatoes. Although there are negative impacts of fungicides usage on fresh produce, at present, it is the most common method of eliminating diseases. UV-C hormesis was used in this study as a trending non-chemical postharvest treatment.Research Method : Tomato varieties ‘Thilina’ and ‘Roma’ were used to check the efficacy of UV-C treatments. Five different UV-C dosages (0, 1, 2, 3, 4, 5 kJ/m2) were applied to pure cultures of C. coccodes (254 nm at a distance of 15 cm). The selected dosages (3.0 and 4.0 kJ/m2) were tested on the effect of anthracnose disease development in vivo and the change in postharvest quality parameters (weight loss, firmness, shelf life, antioxidant and total phenolic content). Antifungal activity of the peel was investigated using Cladosporium bioassay. Findings : Weight loss of treated ‘Thilina’ variety has significantly increased (P < 0.05). The antioxidant activity and the total phenolic content of both treated varieties have increased. The firmness has significantly retained in treated ‘Thilina’ variety. Further, the shelf life has significantly extended in both treated varieties by approx. 2 folds compared to the non-treated control. All tested tomato samples indicated the presence of antifungal compounds in their peels. Therefore, to suppress anthracnose disease 4.0 kJ/m2, and 3.0 and 4.0 kJ/m2 are the most suitable UV-C dosage for ‘Thilina’ and ‘Roma’ respectively.Research Limitations : This research is based on the available tomato cultivars in the market.Originality / Value : This is a non-chemical treatment which could be utilized by farmers in future, to control postharvest anthracnose in tomatoes.Purpose : Anthracnose disease caused by Colletotrichum coccodes is a significant postharvest disease in tomatoes. Although there are negative impacts of fungicides usage on fresh produce, at present, it is the most common method of eliminating diseases. UV-C hormesis was used in this study as a trending non-chemical postharvest treatment.Research Method : Tomato varieties ‘Thilina’ and ‘Roma’ were used to check the efficacy of UV-C treatments. Five different UV-C dosages (0, 1, 2, 3, 4, 5 kJ/m2) were applied to pure cultures of C. coccodes (254 nm at a distance of 15 cm). The selected dosages (3.0 and 4.0 kJ/m2) were tested on the effect of anthracnose disease development in vivo and the change in postharvest quality parameters (weight loss, firmness, shelf life, antioxidant and total phenolic content). Antifungal activity of the peel was investigated using Cladosporium bioassay. Findings : Weight loss of treated ‘Thilina’ variety has significantly increased (P < 0.05). The antioxidant activity and the total phenolic content of both treated varieties have increased. The firmness has significantly retained in treated ‘Thilina’ variety. Further, the shelf life has significantly extended in both treated varieties by approx. 2 folds compared to the non-treated control. All tested tomato samples indicated the presence of antifungal compounds in their peels. Therefore, to suppress anthracnose disease 4.0 kJ/m2, and 3.0 and 4.0 kJ/m2 are the most suitable UV-C dosage for ‘Thilina’ and ‘Roma’ respectively.Research Limitations : This research is based on the available tomato cultivars in the market.Originality / Value : This is a non-chemical treatment which could be utilized by farmers in future, to control postharvest anthracnose in tomatoes.

Shelf-life of Bacillus subtilis B298 inclusion in biopesticide microencapsule formula and its efficacy in suppressing anthracnose disease on chili

Bacillus subtilis B298 is an antagonistic bacterium isolated from the rhizosphere of potatoes. It is capable in controlling diseases both caused by fungi and bacteria. Inclusion of B. subtilis B298 in biopesticide microencapsule formula (BMF) is an effort to extend its shelf life, which maintain its stability and relatively more resistant to environmental change conditions. This study aimed to determine the shelf life of B. subtilis B298 in BMF, and its effectiveness in BMF to suppress chili anthracnose disease. Application of B. subtilis B298 in BMF was conducted by chili seed coating for 24 hr, after seed sowing the biopesticide was applied again by watering the roots of plants, i.e. 10, 20 and 30 d after planting. The experiment was arranged in a completely randomized block design with 4 treatments (control, B. subtilis B298 BMF, fungicide and combination of B. subtilis B298 BMF and fungicide), each treatment was repeated 6 times. Variables observed were; B. subtilis B298 population in the BMF, the disease intensity and infection rate by Colletotrichum sp. The study showed that B. subtilis B298 in BMF was capable to survive for 5 wk with a population of 14.4 107 cfu/g and suppressed chili anthracnose by 53.71%.

Management of postharvest anthracnose of banana using inorganic salts alone and in combination with hot water

Experiments were conducted to evaluate selected inorganic salts alone and in combination with hot water for management of banana anthracnose disease. The efficacy of hot water treatment (HWT) and either sodium bicarbonate (SBC), sodium carbonate (SC) or sodium hypochlorite (SH) applied alone and in combination to suppress anthracnose disease was investigated in both naturally infected and artificially inoculated banana fruit cv. Kolikuttu during the storage. The in vitro efficacy of the selected salts on the inhibition of colony growth of the anthracnose fungal pathogen was also tested. Postharvest treatment involving fruit dipped for 30 min in 1% (w/v) SC following HWT (50°C, 3 min) reduced the severity of anthracnose, which was statistically similar (P > 0.05) with that of homai fungicide treatment. Among the tested salts, SC recorded the significantly highest (P < 0.05) in vitro inhibition of mycelial growth of anthracnose pathogen. Integration of SC with HWT could be a commercially acceptable and economically feasible non-fungicidal approach for the postharvest management of anthracnose during the storage of banana.

Biodiversity of Endophytic Fungi from Lowland Tomato Plants and Their Potential as Biological Control Agents for Anthracnose Disease in Chili Plants at Green House

Anthracnose disease is one of important diseases of fruit crops that need to be controlled, influence of chili production in Indonesia, and cause significant yield loses of economic importance. Control of the disease until now using fungicides that have negative impact for the environment and the results have not been satisfactory. Based on that, alternative methods of control are studied. The control method is the use of endophytic fungi that isolated from tomato roots in the lowlands. The purpose of this study was to obtain candidates for endophytic fungi that could potentially be biological agents for controlling anthracnose disease. The stages of the research are antagonism test using dual culture method, identification, application suspension of endophytic fungi using root immersion method. Endophytic fungi be isolated from root lowland tomato plants (Jombang and Kediri) and was cultured on Potato Dextrose Agar (PDA) media to get pure culture so identified based on book Illustrated Genera of Imperfect Fungi by H. L. Barnett, Barry B. Hunter (1998). Chilli plants were inoculated with pathogens (Colletotrichum sp.) using spray techniques on leaves then endophytic fungi was applied. The identification results get Penicillium sp., Aspergillus sp., Fusarium sp., antagonistic test get 7 candidate isolates were able to inhibit the growth of Colletotrichum sp., and application suspension of endophytic fungi showed that J8 had highest potential to suppress anthracnose disease in chili plants at greenhouse (51.94%).

Rhizobacteria Bacillus spp. induce resistance against anthracnose disease in chili (Capsicum annuum L.) through activating host defense response

Bacillus sp. BSp.3/aM, a beneficial rhizobacteria, was analyzed for the ability to improve plant health of chili by suppressing anthracnose disease. In the dual culture assay, the bacterium Bacillus sp. BSp.3/aM was found inhibitory to Colletotrichum capsica (6 mm). Further, upon seed priming, it reduced the seed-borne incidence of C. capsici (2%) and improved seedling vigor (1374 ± 7.15 vigor index) and germination (98 ± 0.57 %) of chili seedlings. Under greenhouse conditions, seed priming resulted in reducing the anthracnose disease incidence up to 20%. Induction of resistance against invading pathogen is through enhancing the activities of defense-related enzymes and higher accumulation of phenolic compounds in the host plant. The activity of phenylalanine ammonia-lyase (PAL; 95 units) was more at 48 hpi; peroxidase (POX; 6.49 units) at 24 hpi; polyphenol oxidase (PPO; 5.81 units) at 24 hpi and lipoxygenase (LOX; 9.9units) at 24 hpi. Maximum accumulation of the phenolics and chitinase accumulation was observed in BSp.3/aM + pathogen treated seedlings 120 hpi (94.7 μg/g tissue) and at 96 hpi (9.36 units), respectively. Thus, increased activities of defense-related enzymes (PAL, POX, PPO, LOX, and chitinase) correlated well with the decreased anthracnose incidence. Induced systemic resistance (ISR) mediated by PGPR was due to the upregulation of defense-related enzymes and by the accumulation of phenolic compounds.

Bio-Sulfur Pre-Treatment Suppresses Anthracnose on Cucumber Leaves Inoculated with Colletotrichum orbiculare

Bio-sulfur can be produced in the process of desulfurization from a landfill and collected by some microorganism such as Thiobacillus sp. as a sulfur element. In order to investigate practical use of bio-sulfur as an agent for controlling plant disease, in vitro antifungal activity of bio-sulfur was tested against Colletotrichum orbiculare known to cause cucumber anthracnose. Efficacy of bio-sulfur for suppressing anthracnose disease was also evaluated in vivo using cucumber leaves. Mycelial growth of C. orbiculare on medium containing bio-sulfur was inhibited. Disease severity of cucumber leaves pre-treated with bio-sulfur was significantly decreased compared to that of untreated ones. To illustrate how bio-sulfur could suppress anthracnose disease, structures of cucumber leaves infected with C. orbiculare were observed under a fluorescent microscope and a scanning electron microscope (SEM). Cucumber leaves pre-treated with bio-sulfur showed a low rate of appressorium formation whereas untreated ones showed abundant appressoria. Shrunk fungal hyphae were mostly observed on bio-sulfur-pretreated leaves by SEM. Similar results were observed on leaves pre-treated with a commercial fungicide Benomyl®. These results suggest that inhibition of appressorium formation of C. orbiculare by bio-sulfur may contribute to its suppression of cucumber anthracnose.

Bio-management of anthracnose disease in chilli with microencapsulates containing Bacillus subtilis B298

The objectives of this research were to evaluate the Bacillus subtilis B298 strain as antagonist of Colletotrichum sp. pathogens in vitro, and to evaluate the ability of microencapsulated B. subtilis B298 strain formula to suppress anthracnose disease of chilli in the fields. Methods for antagonism test of B. subtilis B298 against Colletotrichum sp. was conducted by dual culture on potato dextrose agar medium. Microencapsulated formula 2g. L−1 of B. subtilis B298 spray was used as control of anthracnose disease in the fields. The four treatments were arranged by Randomized Completely Block Design consist of control, B. subtilis B298, fungicide, and combination of B. subtilis B298 and fungicide with six replications. The measured variable in vitro was inhibition percentage, and that of in field were; disease intensity, infection rates and plant total phenol. Results showed that B. subtilis B298 strain inhibited 56% growth of Colletotrichum sp. in vitro, micro capsulated B. subtilis B298 reduced disease intensity by 48% with infection rates of 0,02 unit.day−1. Microencapsulated B. subtilis B298 induced plant systemic disease resistance on chili as total phenol of the treated plant increased.

Plant growth promoting rhizobacteria- Bacillus amyloliquefaciens improves plant growth and induces resistance in chilli against anthracnose disease

The present study was aimed to screen plant growth promoting rhizobacteria (PGPR) for their effect on induction of resistance in chilli (Capsicum annum L.) against anthracnose disease. A total of 59 PGPR were evaluated for their antagonistic activity against Colletotrichum truncatum and only fourteen PGPR were able to inhibit the mycelial growth of the pathogen. The pathogenicity and root colonization of the selected PGPR showed that out of fourteen isolates only eight isolates of Achromobacter, Bacillus, Burkholderia, Enterobacter, Ochrobactrum and Providencia genera were able to be both non-pathogenic and possessed the ability to colonize the host plant. Among the PGPR isolates, seed treatment with Bacillus amyloliquefaciens resulted in maximum enhancement of seed germination (84.75%), seedling vigor (1423.8) along with an increase in vegetative growth parameters. Significant disease protection of 71% against anthracnose disease was observed in plants pretreated with B. amyloliquefaciens followed by B. cepacia and P. rettgeri, under greenhouse conditions. The induced resistance obtained upon PGPR treatment was in line with higher activity of defense enzymes [phenylalanine ammonia lyase (PAL), peroxidase (POX), polyphenol oxidase (PPO) and β-1,3-glucanase]. It was observed that, almost one to two-fold increase in enzyme activities was observed in PGPR treated challenge inoculated seedlings compared to control inoculated seedlings. The results evidenced that the PGPR- B. amyloliquefaciens possesses immense potential to increase the plant growth apart from suppressing anthracnose disease in chilli.

Potential of Bacillus spp. as biological control agents to suppress anthracnose disease of dragon fruit (Hylocereus undatus)

Potential of <i>Bacillus</i> spp. as biological control agents to suppress anthracnose disease of dragon fruit (<i>Hylocereus undatus</i>)

KESINTASAN BEBERAPA JAMUR ANTAGONIS PADA BUAH CABAI DAN POTENSINYA DALAM MENEKAN PENYAKIT ANTRAKNOSA YANG DISEBABKAN OLEH COLLETOTRICHUM GLOEOSPORIOIDES

Persistence of several antagonistic fungus on chilli and its potential to suppress anthracnose disease caused by Colletotrichum gloeosporioides. Anthracnose disease caused by C. gloeosporioides is one of the important diseases on chilli because its directly gives negative impact on chilli production. The aim of this research was to obtain the superior antagonistic fungi that have ability to persist on chili fruit and potential to control anthracnose disease caused by C. gloeosporioides The experiment consist of two units: 1. Testing of persistence ability of antagonistic fungi on chilli fruit, 2. Testing the potential of antagonistic fungi to suppress anthracnose disease on chilli fruit. Both of the test used Randomized Block Design (RBD) with 10 treatments and 4 replication, each of replication consist of 4 chilies fruit. Those treatments were Trichoderma-PP1, Trichoderma-PP3, Trichoderma-AG2, Trichoderma-PYK3, Paecilomyces-PP6, Paecilomyces-PP7, Paecilomyces-AG4, Paecilomyces-PYK4, Aspergillus PP2 and without antagonistic fungi (control). The result indicated that all antagonistic fungi isolate could persist on chili fruit. The highest persistence were Trichoderma-PP3 and TrichodermaAG2 (95.83%) and the lowest belonged to Paecilomyces-PP7 (50%). Trichoderma-PP3 and Trichoderma-AG2 were the best isolates for suppressing anthracnose disease caused by C. gloeosporioides.

Best Management Practices Effects on Anthracnose Disease of Annual Bluegrass

Increased N fertilization, mowing height, and sand topdressing are management practices that can suppress anthracnose disease of annual bluegrass [Poa annua L. f. reptans (Hausskn) T. Koyama; ABG] caused by Colletotrichum cereale Manns. A 3‐yr field study evaluated the relative importance and interactions of these factors on anthracnose severity, turfgrass quality, and ball roll distance (BRD) on ABG turf in North Brunswick, NJ. A factorial combination of mowing height (2.3 and 3.2 mm), N fertilization (100 and 200 kg ha−1 yr−1), and sand topdressing (46 and 98 Mg ha−1 yr−1 in 2012; 37 and 81 Mg ha−1 yr−1 during 2013 and 2014) was arranged in a split‐split‐plot design with four replications. The practice of applying greater N fertilization (200 kg ha−1) provided the greatest reduction in disease severity and improvement in quality than the practices of higher mowing (3.2 mm) or greater sand topdressing (98 or 81 Mg ha−1). Combining greater N with higher mowing and greater sand topdressing provided acceptable disease suppression without the use of fungicides during moderate but not severe anthracnose epidemics. Higher mowing often produced unacceptable BRD (&lt;2.9 m) especially when combined with greater N fertilization; whereas, under lower mowing, BRD was acceptable on most observation dates (91–96%) and less influenced by greater N fertilization. Thus, when adjustments in best practices for anthracnose management are needed to enhance BRD; lowering the mowing height will provide that enhancement while not greatly increasing the risk for anthracnose especially when greater N and increased topdressing practices are also employed.

Combined treatment with hot water and UV-C elicits disease resistance against anthracnose and improves the quality of harvested mangoes

This research investigated the effects of hot water, UV-C irradiation and their combination on the induction of resistance to anthracnose disease and on quality improvement in harvested mangoes. Naturally infected mango fruits were harvested, surface-disinfested with a solution of 100 ppm sodium hypochlorite and air dried. The fruits were then treated with UV-C irradiation at a dose 6.16 kJ m−2, with hot water at 55 °C for 5 min or with hot water followed by UV-C irradiation. Untreated fruits served as the control. All fruit samples were kept at 13 °C for 12 days. The combined treatment significantly suppressed the severity of anthracnose symptoms compared with either single treatment. Additionally, the specific activities of key plant defense-related enzymes, such as phenylalanine ammonia lyase (PAL), peroxidase (POD), chitinase (CHI) and β-1,3-glucanase (GLU), increased in both the peel and the pulp of the mango fruits. The expressions of the MI-PAL, MI-POD, MI-CHI and MI-GLU genes in the mango peel were markedly enhanced in the fruits treated with the combined treatment in comparison with those treated with hot water or UV-C alone, while the control fruits showed the lowest expression of these genes. The combined treatment or UV-C treatment alone significantly delayed fruit ripening by maintaining fruit firmness, retarding the progressive increase of total soluble solids (TSS) and delaying the decrease in titratable acidity (TA). Weight loss was not significantly different among the treatments. The results suggested that the combination of hot water and UV-C treatment may be used as a tool not only for suppressing anthracnose disease but also for improving the quality of harvested mangoes by inducing the expression of plant defense-related genes.

Eliciting Plant Defense on Anthracnose Disease in Chili (Capsicum annuum Linn.) by Sodium Nitroprusside Solution

The study on the induction of plant defense against to anthracnose disease of chili by sodium nitroprusside solution was investigated during pre- and post-harvest. Pre-harvest treatment was conducted by spraying the chili plants with sodium nitroprusside (SNP, nitric oxide donor) solution at 0 (control), 0.05 and 0.1 mM every 3 days for 9 times before inoculating with the spore suspension of Colletotrichum gloeosporioides (the causal agent of anthracnose disease) and then sprayed with SNP again 1 time after inoculating. The results revealed that 0.1 mM SNP was the best concentration to suppress anthracnose disease by reducing disease incidence and disease index on chili leaves, and showing the lowest loss of yield caused by anthracnose disease. This founding also showed that either pathogenic inoculation or SNP treatment had ability to induce the activities of peroxidase (POD) and phenylalanine ammonia lyase (PAL) of chili leaves, particularly the chili plant inoculated with pathogenic fungi followed by treated with 0.1 mM SNP showed the highest POD and PAL activities. Post-harvest treatment was done by inoculating the mature chilli fruit with C. capcisi for 4 h and followed by dipping in 0 (control) and 4 mM SNP. All fruit samples were kept at 13C for 15 days. The results showed that chili fruit dipped with 4 mM SNP reduced disease incidence, disease index, delayed weight loss, respiration rate, ethylene production, and also maintained the changes of fruit color (ΔE) better than non-treated fruit (control). The activities of chitinase (CHI) and β-1,3-glucanase (GLU) in chili fruit were induced by SNP with the highest peak on day 6 of storage but they were not significant different with the control fruit. These results indicated that SNP might potential leading to the reduction of anthracnose disease in chili by eliciting plant defense related enzymes in both pre- and post-harvest periods.