Antalya İli Kumluca İlçesindeki Biber Yetiştirilen Seralarda Domates Lekeli Solgunluk Virüsü (Tomato spotted wilt tospovirus-TSWV)’ nün Yaygınlığı ve Konukçu Yabancı Ot Türlerinin Belirlenmesi

There are many viruses that infect pepper and limit its production. Among these viruses, Tomato spotted wilt tospovirus (TSWV) infects crops in 35 plant families that are economically important, including pepper. In the present study; totaly 156 leaf samples were collected, including 57 from pepper plants showing virus-like symptoms and 99 from weeds and/or plants other than peppers in and around the greenhouse, through surveys carried out in pepper greenhouses in Kumluca district of Antalya province, from September to December 2020. Then, the plant leaf samples were tested to determine TSWV infections by the Double Antibody Sandwich Enzyme-linked Immunosorbent Assay (DAS-ELISA) method. According to result of the tests, it was determined that 55.76% of the tested leaf samples were infected with TSWV, while this rate was determined as 96.49% for pepper samples and 32.32% for other plant samples. During the survey studies, it was revealed that the leaf samples of 13 out of 31 weed and different plant species except pepper were infected with at least one of the viruses. In addition, pepper plants showing symptoms TSWV-like symptoms in pepper greenhouses were counted during the survey, and the prevalence of this virus disease was calculated on the basis of Kumluca district and neighborhoods. As a result of these calculations, the prevalences of TSWV; for Kumluca, Mavikent, Beykonak, Salur, Hacıveliler, Adrasan, Merkez, and Kavakköy were determined as 26.93%, 26.92%, 32.27%, 20.66%, 21.13%, 17.66%, 13%, and 25%, respectively.

Eliciting Plant Defenses Through Herbivore-Induced Plant Volatiles’ Exposure in Sweet Peppers

Insect herbivory activates plant defense mechanisms and releases a blend of herbivore-induced plant volatiles (HIPVs). These volatile compounds may be involved in plant-plant communication and induce defense response in undamaged plants. In this work, we investigated whether the exposure of sweet pepper plants to HIPVs [(Z)-3-hexenol, (Z)-3-hexenyl acetate, (Z)-3-hexenyl propanoate, (Z)-3-hexenyl butanoate, hexyl butanoate, methyl salicylate and methyl jasmonate] activates the sweet pepper immune defense system. For this, healthy sweet pepper plants were individually exposed to the each of the above mentioned HIPVs over 48 h. The expression of jasmonic acid and salicylic acid related genes was quantified. Here, we show that all the tested volatiles induced plant defenses by upregulating the jasmonic acid and salicylic acid signaling pathway. Additionally, the response of Frankliniella occidentalis, a key sweet pepper pest, and Orius laevigatus, the main natural enemy of F. occidentalis, to HIPV-exposed sweet pepper plants were studied in a Y-tube olfactometer. Only plants exposed to (Z)-3-hexenyl propanoate and methyl salicylate repelled F. occidentalis whereas O. laevigatus showed a strong preference to plants exposed to (Z)-3-hexenol, (Z)-3-hexenyl propanoate, (Z)-3-hexenyl butanoate, methyl salicylate and methyl jasmonate. Our results show that HIPVs act as elicitors to sweet pepper plant defenses by enhancing defensive signaling pathways. We anticipate our results to be a starting point for integrating HIPVs-based approaches in sweet pepper pest management systems which may provide a sustainable strategy to manage insect pests in horticultural plants.

Characterization and pathogenicity of a Pythium aphanidermatum isolate causing ‘damping off’ in pepper seedlings

<p>The production of the pepper seedling (<em>Capsicum annuum</em>) is affected by the fungal complex that causes the ‘damping-off’, in which some species of the oomycete <em>Pythium</em> spp., stand out. The objective of the present study was to identify the causal agent of the death of pepper plants and evaluate its pathogenicity in pepper seeds and seedlings. A fast and aggressive growing oomycete was isolate from pepper plants, morphologically identified as P. aphanidermatum based on its sexual and asexual reproduction structures and, by molecular techniques. This isolate had a high degree of<em> in vitro</em> pathogenicity in pre-emergence and post-emergence in chile, showing 100% mortality. In addition, it presented a high rate of mycelial growth in different culture media (V8-Agar, Corn Agar, Corn Potato Agar, Potato Dextrose Agar, Czapek &amp; Oat Agar), being in V8-Agar medium the only medium where it developed reproduction structures sexual and asexual. The isolation presented a mycelial growth rate of 58.3 ± 0.3 mm / day at 26 ± 2 °C in PDA medium. Due to its rapid growth and its high degree of pathogenicity <em>in vitro</em>, it is an unusual and aggressive isolate for pepper seedlings.</p>

Effect of Graft and Nano ZnO on Nutraceutical and Mineral Content in Bell Pepper

The objective of this experiment was to evaluate the effects of grafting, zinc oxide nanoparticles (ZnO NPs), and their interaction on the nutritional composition of bell pepper plants. The treatments evaluated included grafted and non-grafted pepper plants with four concentrations of ZnO NPs (0, 10, 20, 30 mg L−1) applied to the foliage. The following parameters were evaluated: content of N, P, K+, Ca2+, Mg2+, Mn2+, Zn2+, Fe2+, Cu2+, total antioxidants, ascorbic acid, total phenols, glutathione, total proteins, fruit firmness, and total soluble solids. Grafting increased the content of N 12.2%, P 15.9%, K+ 26.7%, Mg2+ 20.3%, Mn2+ 34.7%, Zn2+ 19.5%, Fe2+ 18.2%, Cu2+ 11.5%, antioxidant capacity 2.44%, ascorbic acid 4.63%, total phenols 1.33%, glutathione 7.18%, total proteins 1.08%, fruit firmness 8.8%. The application of 30 mg L−1 ZnO NPs increased the content of N 12.3%, P 25.9%, Mg2+ 36.8%, Mn2+ 42.2%, Zn2+ 27%, Fe2+ 45%, antioxidant activity 13.95%, ascorbic acid 26.77%, total phenols 10.93%, glutathione 11.46%, total proteins 11.01%, and fruit firmness 17.7% compared to the control. The results obtained demonstrate the influence of the use of grafts and ZnO NPs as tools that could improve the quality and nutrient content in fruits of bell pepper crops.

Effect of aqueous extracts of three different plants on Myzus persicae Sulzer (Hemiptera: Aphididae) infesting pepper plants under laboratory conditions

This study aimed to determine the percentage infestation and population parameters of the green peach aphid Myzus persicae under laboratory conditions and evaluate the effect of aqueous extracts of three different plants (pot marigold: Calendula officinalis, mint: Mentha viridis and rosemary: Salvia rosmarinus) on the mortality of this aphid. Extracts of these plants were used at three concentrations (C1 = 15%, C2 = 30% and C2 = 45%). Results indicate a percentage infestation of 76.9 ± 9.4%, a mean relative growth rate of 0.062 ± 0.007 and generation time of 11.12 ± 1.42 days. All treatments reduced the numbers of aphids and statistically significantly reduced the number (α < 0.01) recorded after treatment with C1, C2 and C3 of each extract. C. officinalis extract was more effective than those of M. viridis and S. rosmarinus. The highest mortality (69.82 ± 5.23%) and efficacy (61.71 ± 4.46%) were recorded for the C3 of aqueous extract of C. officinalis, whereas the lowest mortality (38.24 ± 2.42%) and efficacy (32.41 ± 1.23%) were recorded for the C1 of extract of M. viridis. The data provided indicate that aqueous extracts of C. officinalis, M. viridis and S. rosmarinus have an insecticidal effect on M. persicae and can be integrated into a pest management strategy to reduce M. persicae abundance on pepper plants.

Effects of Se Application on Polyamines and Carbon–Nitrogen Metabolism of Pepper Plants Suffering from Cd Toxicity

Previous studies have shown that the application of selenium (Se) can efficiently mitigate the toxic effects of cadmium (Cd) on various crops. The objective of the present work is to decipher the mechanisms responsible for the efficiency of Se against the effects of Cd in pepper plants, with respect to the carbon and nitrogen metabolism. The following were analyzed: the concentrations of anions related with this metabolism, such as nitrates, nitrites, and ammonium, the activities of different enzymes such as nitrate reductase, nitrite reductase, and glutamate synthase, polyamines in their different forms, organic acid salts, amino acids, and sugars in the leaf and root tissues of the pepper plants grown in a hydroponics system. Four different treatments were applied: plants without Cd or Se applied (−Cd/−Se); plants grown with Cd added to the nutrient solution (NS) but without Se (+Cd/−Se); plants grown with Cd in the NS, and with the foliar application of Se (+CD/+SeF); and lastly, plants grown with Cd in the NS, and with Se applied to the root (+Cd/+SeR). The metabolites and enzymes related with carbon and nitrogen metabolism were analyzed 15 days after the application. The results showed the superiority of the +Cd/+SeR treatment with respect to the +Cd/+SeF treatment, as shown by an increase in the conjugated polyamines, the decrease in glutamate and phenylalanine, and the increase of malate and chlorogenic acid. The results indicated that SeR decreased the accumulation and toxicity of Se as polyamine homeostasis improved, defense mechanisms such as the phenylpropanoid increased, and the entry of Cd into the plants was blocked.

Comparison of Frequentist and Bayesian Generalized Linear Models for Analyzing the Effects of Fungicide Treatments on the Growth and Mortality of Piper Nigrum

Foot rot disease poses a devastating threat to pepper agriculture. In Vietnam, conventionally, fungicides are the control methods used against the disease. However, the practical effectiveness of fungicide treatment has yet to be quantitatively assessed. To fill this gap a three-factorial experiment was conducted, the factors of which were fungicide application, soil type, and infection pathway, with plant mortality and plant growth as the target variables. Two of the most common fungicides were chosen, including Agrifos 400 (potassium phosphonate) and Aliette 800WG (fosetyl-Al). The two fungicides were used in multiple treatment plans, with soil drenching selected as the means of controlling foot rot disease on red basalt soil and red basalt soil added with organic matter in a greenhouse experiment. Three-month-old pepper (Piper nigrum) plants were treated with Agrifos (application interval of 10 and 20 days), Aliette (application interval of 30 and 60 days), and a combination of both fungicides at half doses. Pepper plants were infected with the fungus Pythium spp. from soil or by direct inoculation. To assess the effect of fungicides on foot rot mortality and the growth of pepper plants, multiple generalized linear models were set up using frequentist and Bayesian approaches. Generally, both procedures suggest the same conclusions for model selection in terms of the Akaike information criterion (AIC) and the deviance information criterion (DIC). Fungicide type was found to be the main factor that affected the survival of plants. Most of the treatments (except Aliette, with an interval of 60 days) effectively reduced the mortality. The usage of fungicides affected the growth of plants in interaction with soil types. Aliette suppressed the growth of plants, especially on red soil, while Agrifos had no effect on the growth of pepper plants. The combined application of Agrifos and Aliette with half doses proves to be a promising solution for balancing cost and effectiveness in protecting plants against foot rot pathogens without affecting their growth. In our case, under the inhomogeneity of variance and unbalanced samples, the Bayesian inference appeared to be the most useful because of its flexibility in terms of model structure.