Annuum Var Research Articles

NUTRIENT UPTAKE, PROLINE CONTENT AND ANTIOXIDANT ENZYMES ACTIVITY OF PEPPER (Capsicum annuum L.) UNDER HIGHER ELECTRICAL CONDUCTIVITY OF NUTRIENT SOLUTION CREATED BY NITRATE OR CHLORIDE SALTS OF POTASSIUM AND CALCIUM

This study was conducted to evaluate effects of higher conductivity of nutrient solution created by nitrate or chloride salts of potassium and calcium on growth characteristics of pepper plants (Capsicum annuum var annuum) during four months of growth period. Two EC5 and EC8 dS/m of Hoagland nutrient solution were prepared using various salt combinations, namely; KCl + CaCl2, KNO3 + CaNO3, and KNO3 + CaNO3 + NaCl. Hoagland nutrient solution with EC 1.8 dS/m was served as control. Higher conductivity treatments had different effects on pepper plant growth. The most significant reduction in growth parameters of plant height, shoot fresh weight, fruit yield and nutrients uptake were in plants treated with KCl + CaCl2 particularly at EC8. Application of KNO3 + CaNO3 particularly at EC5 showed no difference with control regarding many growth parameters. Application of KNO3 + CaNO3 at EC5 resulted in higher shoot fresh weight compared to control. All salinity treatments except KNO3 + CaNO3 at EC5 reduced fruit yield compared to control. Treatments of KCl + CaCl2 and KNO3 + CaNO3 + NaCl particularly at EC8 of nutrient solution resulted in higher leaf proline concentration, catalase and peroxidase enzymes activity compared to control. Other conductivity treatments showed no difference in catalase or peroxidase enzymes activity. The significant lowest amount of leaf N, K, Mg and Ca was in KCl + CaCl2 at EC8. On the other hand, the highest leaf macronutrient concentrations were in KNO3 + CaNO3 at EC5 and/or EC8 that showed only higher leaf N and Ca values compared to control. Leaf micronutrient concentrations were highest in KNO3 + CaNO3 at EC5 that generally showed no difference with control plants. However, application of KCl + CaCl2 particularly at EC8 and to less extent KNO3 + CaNO3 + NaCl at EC8 reduced leaf micronutrient concentrations. Application of KNO3 + CaNO3 at EC5 increased and KCl + CaCl2 or KNO3 + CaNO3 + NaCl at EC8 decreased the leaf Fe concentration compared to control plants.

Deposition, Distribution, Metabolism, and Reduced Application Dose of Thiamethoxam in a Pepper-Planted Ecosystem.

To decrease the application dose of thiamethoxam (TMX) to control the pepper whitefly (Bemisia tabaci Q), the deposition, dissipation, metabolism, and field efficacy of TMX were investigated in a pepper (Capsicum annuum var. grossum)-planted ecosystem using eight types of nozzles at six concentrations (56.25, 41.25, 26.25, 21.0, 15.75, and 10.5 g a.i./hm2). The initial deposition amount of TMX in the pepper plant first increased and then decreased with increasing application dose. The optimum spray conditions of TMX were found to be a droplet size of 200 μm volume median diameter and a spray volume of 350 L/hm2. Moreover, three metabolites, TMX-dm, clothianidin (CLO), and C5H8O2N3SCl, were detected in the pepper-planted system. The dissipation rate of TMX in the pepper-field ecosystem was leaves > stems > fruits > roots > soils. The results revealed the deposition and fate of TMX in the pepper-field ecosystem, and the application dose could be reduced by 20% based on the minimum recommended dose for controlling pepper whitefly.

Pan-plastome approach empowers the assessment of genetic variation in cultivated Capsicum species

Pepper species (Capsicum spp.) are widely used as food, spice, decoration, and medicine. Despite the recent old-world culinary impact, more than 50 commercially recognized pod types have been recorded worldwide from three taxonomic complexes (A, B, and P). The current study aimed to apply a pan-plastome approach to resolve the plastomic boundaries among those complexes and identify effective loci for the taxonomical resolution and molecular identification of the studied species/varieties. High-resolution pan-plastomes of five species and two varieties were assembled and compared from 321 accessions. Phyloplastomic and network analyses clarified the taxonomic position of the studied species/varieties and revealed a pronounced number of accessions to be the rare and endemic species, C. galapagoense, that were mistakenly labeled as C. annuum var. glabriusculum among others. Similarly, some NCBI-deposited plastomes were clustered differently from their labels. The rpl23-trnI intergenic spacer contained a 44 bp tandem repeat that, in addition to other InDels, was capable of discriminating the investigated Capsicum species/varieties. The rps16-trnQ/rbcL-accD/ycf3-trnS gene set was determined to be sufficiently polymorphic to retrieve the complete phyloplastomic signal among the studied Capsicum spp. The pan-plastome approach was shown to be useful in resolving the taxonomical complexes, settling the incomplete lineage sorting conflict and developing a molecular marker set for Capsicum spp. identification.

Candidate Markers Assay for Capsicum Pungency

Effectiveness of candidate markers for differentiating the pungent, slightly pungent and non-pungent chilli lines and their use in marker assisted selection programmes was assessed. Two pungent C. annuum, one pungent C. chinense, two pungent C. frutescens, one non-pungent C. annuum, two non-pungent C. annuum var. grossum and two slightly pungent C. annuum var. acuminatum cultivars were analysed using MAP1 marker for locus Pun1, CS and B markers for locus CS, Pun11 marker for locus Pun1 of C. annuum and Pun13 marker for locus Pun1 of C. frutescens. This paper discusses the universal suitability of these candidate markers in MAS programmes for levels of pungency in Capsicum. Through sequencing of markers it is further shown that the proposed CS gene lies within the Pun1 locus and since Pun1 markers are missing in non-pungent and slightly pungent lines, we propose that genes other than Pun1 are involved in pungency mechanism in Capsicum spp.

Variability in the Phytochemical Contents and Free Radical-Scavenging Capacity of Capsicum annuum var. glabriusculum (Wild Piquin Chili).

The variability in the phytochemical concentrations of Capsicum annuum var. glabriusculum has not been extensively analyzed among wild populations and ecologic niches in its phylogeographic area. This study aimed to determine the variations in the phytochemical and antioxidant contents of the wild Piquin chili. The total flavonoid content of hydroalcoholic extracts (0.06 to 0.70 mg equivalent of quercetin per gram of dry weight (mg QE/g DW)), free radical-scavenging capacity for 2,2-diphenyl-1-picrylhydrazyl (DPPH. ) radicals (0.55 to 8.55 mm TE/g DW), amount of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+ ) in aqueous extracts (18.13 to 107.6 mm TE/g DW) and pungency (21,760 to 88,476 Scoville heat units) were highly variable. By analyzing the spatial distribution using the first three principal components, correlations between the phytochemical content and the free radical-scavenging capacity (in both extracts) and flavonoid and phenolic contents (in the hydroalcoholic extract) were observed. Consistent with the statistical analysis, the spatial analysis showed intraregional differences in composition patterns, with an emphasis on central and coastal areas. Flavonoid contents, polyphenol contents and free radical-scavenging activity were the phytochemical components that mainly contributed to the diversity of the population.

Chilli leaf curl virus infection downregulates the expression of the genes encoding chloroplast proteins and stress-related proteins.

Virus infection alters the expression of several host genes involved in various cellular and biological processes in plants. Most of the studies performed till now have mainly focused on genes which are up-regulated and later projected them as probable stress tolerant/susceptible genes. Nevertheless, genes which are down-regulated during plant-virus interaction could also play a critical role on disease development as well as in combating the virus infection. Hence, to identify such down-regulated genes and pathway, we performed reverse suppression subtractive hybridization in Capsicum annuum var. Punjab Lal following Chilli leaf curl virus (ChiLCV) infection. The screening and further processing suggested that majority of the genes (approximately 35% ESTs) showed homology with the genes encoding chloroplast proteins and 16% genes involved in the biotic and abiotic stress response. Additionally, we identified several genes, functionally known to be involved in metabolic processes, protein synthesis and degradation, ribosomal proteins, energy production, DNA replication and transcription, and transporters. We also found 3% transcripts which did not show homology with any known genes. The redundancy analysis revealed the maximum percentage of chlorophyll a-b binding protein (15/96) and auxin-binding proteins (13/96). We developed a protein interactome network to characterise the relationships between proteins and pathway involved during the ChiLCV infection. We identified that the most of the interaction occurs either among the chloroplast proteins (Arabidopsis proteins interactive map) or biotic and abiotic stress responsive proteins (Solanum lycopersicum interactome). Taken together, our study provides the first transcriptome and protein interactome of the down-regulated genes during C. annuum-ChiLCV interaction. These resources could be exploited in deciphering the steps involved in the process of virus infection.

Anthelmintic Activity of Capsicum Annuum var. Longum (Siling-Haba) Placental Extracts Against Gastrointestinal Parasites in Broiler Chicken Stool

Soil-transmitted helminth infection is considered one of the Neglected Tropical Diseases (NTDs) worldwide. The Philippines is one of the countries in Asia with the highest prevalence of parasite infection. Adding to this problem is the resistance of pathogenic nematodes to commercial drugs in livestock hosts. Capsicum species exhibit antiparasitic activity against a wide range of endoparasites as fed to chicken. This study assessed the anthelmintic activity of the Capsicum annuum var. longum against gastrointestinal parasites found in broiler chicken stool and to identify the secondary metabolites from the placental region of the chili’s fruit. Phytochemical screening test indicated the presence of alkaloid, flavonoid, and tannins. The ethanolic extracts of 1%, 10%, 50%, and 100% concentrations were administered to a total of 15 broiler chicken. The anthelmintic efficacy of the plant extract was evaluated through Fecal Egg Count Method. All treatments displayed very high effectiveness on reducing egg parasites count which were comparable to the positive control. The result indicated that the Capsicum annuum var. longum (Siling-Haba) extracts were very effective against gastrointestinal parasites of the broiler chicken. This potency may be attributed to the high level of capsaicinoids content in the fruit. The findings may lead to a new organic anthelmintic drug alternative which is also environmentally sustainable.

Seed Physiological Potential of Capsicum annuum var. glabriusculum Genotypes and Their Answers to Pre-Germination Treatments

Piquin pepper (Capsicum annuum var. glabriusculum) is an important species that supports the economy of rural households; it is part of Mexican gastronomy and it is a highly valuable phytogenetic resource. There has been recent interest in domesticating and exploiting piquin pepper commercially, which has been limited until now due to the low germination rate, and this work had the purpose of promoting germination and determining the physiological capacity of genotypes. Ten piquin pepper genotypes from different geographical origins in Mexico were submitted to 11 pre-germination treatments. A completely randomized experimental design was carried out with arrangement in split-plot. The large plot had the treatments and the small plot had the genotypes. The results showed differences (p < 0.01) among treatments, genotypes, and treatment–genotype interaction. On one hand, treatments gibberellic acid (GA) and mechanical scarification + gibberellic acid (MSGA) increased the physiological potential of genotypes, reaching the highest values of germination speed (GS), germination index (IG) and germination percentage (GP); as well as the lowest values of dead seeds (DS) and hard Seeds (HS). In turn, the genotypes that presented the same condition were G8, G7, and G10. Regarding the interaction, each variable had a different condition. In conclusion, we can increase the physiological potential and solve the dormancy of piquin pepper seed by applying gibberellic acid. Likewise, the best genotypes were G8 and G10.

Green synthesis of silver nanoparticles using Jalapeño Chili extract and thermal lens study of acrylic resin nanocomposites

Green extract from Jalapeño Chili (Capsicum Annuum var Annuum), was used as a reducing agent in the synthesis of silver nanoparticles (AgNPs). The overall reduction was followed by UV–vis and Fourier-transform infrared spectroscopy (FTIR), confirming the formation and growth of AgNPs by the increase in the band intensity of the surface plasmon resonance (SPR) characteristic in silver nanoparticles around 460 nm. The characteristic infrared band of the amine at 3295 cm−1 decreased as the reaction progressed and the spectra showed slight changes indicating the consumption of the initial components of the extract as the reaction proceed. Photocurable acrylic resin and AgNPs were prepared in different concentrations to measure their thermal properties by means of photothermal techniques. Complementary analyzes for the determination of shape, size, crystal structure and composition of the AgNPs such as transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) spectroscopy were done. This is the initial step of a research conducted to study the physical and thermal properties of nanocomposites to improve their performance for possible applications in prosthetic parts, 3D printing and tissue engineering for scaffolds.

Comparison of nutritional, antioxidant vitamins and capsaicin contents in Capsicum annuum and C. frutescens

ABSTRACTPeppers (Capsicum spp.) contain several bioactive compounds with nutritional and pharmaceutical importance, and these differ between pepper types. The assessment of variation and relatedness among genotypes, varieties or accessions of plant species is important in breeding, conservation and management of genetic resources. Four varieties belonging to the Capsicum species: C. annuum L. and C. frutescens L. were characterized by their nutritional constituents, antioxidant vitamins and capsaicin contents. There was variability in nutritional, vitamins and capsaicin contents among varieties. Higher levels of vitamins were found in fresh than in dry samples. Capsaicin content was in the order: C. frutescens var. baccatum L.˃C. annuum var. abbreviatum Fingerh.˃C. annuum var. acuminatum Fingerh.˃C. annuum var. grossum L. Sendt. The varieties were separated into two clusters. The C. frutescens var. baccatum and C. annuum var. abbreviatum were grouped together on the first cluster while C. annuum var. grossum and C. annuum var. acuminatum occupied the second cluster. The varieties of Capsicum spp. contain important micro- and macro-elements and antioxidative vitamins, in varying amounts. The content of the different bioactive compounds can provide significant proportions of the recommended daily allowance and help improve overall health of humans.The diversity in the nutrient and bioactive substances within Capsicum species, and varieties, could be used in pepper breeding to generate improved commercial hybrids.

Contribution of Glycine Betaine and Proline to Water Deficit Tolerance in Pepper Plants

Water stress is the main factor responsible for decreased productivity, which affects the growth and development of crops. Plants respond to stress by accumulating compatible solutes, which have a key role in osmotic adjustment, thereby resulting in osmoprotection of the plants. The loss of water can increase the concentration of compatible osmolytes and molecules that regulate the plant metabolism. These solutes can be metabolized as sugars (sucrose, fructose, trehalosa), amino acids (proline), an amphoteric quaternary amine (glycine betaine), and other low-molecular-weight metabolites. However, among all these compatible solutes, proline and glycine betaine occur the most. Proline is an amino acid that can accumulate in low concentrations under optimal conditions; however, stress conditions contribute to its increased content. Few data are available regarding the levels of endogenous glycine betaine on Solanaceae, which is considered a nonaccumulator under water deficit conditions. The objective of this research was to evaluate the role of compatible osmolytes, glycine betaine and proline, in Capsicum sp. plants under different water deficit conditions. In this study, the presence of endogenous levels of proline and glycine betaine in two species of pepper (Capsicum chinense var. Genesis and Rex and Capsicum annuum var. Padron) were found. The concentration levels of proline were 362, 292, and 246 μmol·g−1 DW for Genesis, Rex and Padron respectively, and irrigation conditions (rehydration) of proline levels increased to 381, 395, and 383 μmol·g−1 DW at 21 days. However, glycine betaine levels were 30–70 μmol·g−1 DW. The relative water content, electrolyte leakage, and soil water potential were also analyzed; therefore, the information suggests that proline contributes better to tolerance to water deficit in the genus Capsicum after 14 days of water deficit treatment. It seems that the contribution of glycine betaine is less effective than that of proline; therefore, it does not have an important role in osmotic adjustment.

Evaluation of genetic relationship among varieties of Capsicum annuum L. and Capsicum frutescens L. in West Africa using ISSR markers

The taxonomic identity of two closely related Capsicum species; Capsicum annuum and Capsicum frutescens in West Africa has not been clarified because they have overlapping morphological traits. Effective control and management measures as well as improvement of crop plants in any breeding programme can only be implemented when plant species are correctly identified. The genetic relationships of the varieties of these Capsicum species were assessed using 10 ISSR primers for the first time. The varieties and species used include C. annuum var. abbreviatum; C. annuum var. acuminatum; C. annuum var. grossum and C. frutescens var. baccatum. PCR amplification of the isolated DNA from the four varieties of Capsicum revealed a total of 75 loci out of which 14 were found to be polymorphic. Average polymorphism information content (PIC) and heterozygosity (He) of the 10 ISSR markers were estimated as 0.67 and 0.78 respectively. The relatedness among the varieties assessed by Unweighted Pair Group Method with Arithmetic Mean (UPMGA) cluster analysis did not separate C. frutescens var. baccatum from the three cultivated varieties of C. annuum. The result from the principal component analysis (PCA) further supports the genetic relatedness and groupings obtained from the cluster analysis. Overall, the study indicated that ISSR markers were effective in assessing the genetic relatedness and revealed genetic homogeneity of the four varieties. Our results, therefore, support the inclusion of C. frutescens var. baccatum as a variety of C. annuum species.

Genetic diversity, population structure, and relationships in a collection of pepper (Capsicum spp.) landraces from the Spanish centre of diversity revealed by genotyping-by-sequencing (GBS)

Pepper (Capsicum spp.) is one of the most important vegetable crops; however, pepper genomic studies lag behind those of other important Solanaceae. Here we present the results of a high-throughput genotyping-by-sequencing (GBS) study of a collection of 190 Capsicum spp. accessions, including 183 of five cultivated species (C. annuum, C. chinense, C. frutescens, C. baccatum, and C. pubescens) and seven of the wild form C. annuum var. glabriusculum. Sequencing generated 6,766,231 high-quality read tags, of which 40.7% were successfully aligned to the reference genome. SNP calling yielded 4083 highly informative segregating SNPs. Genetic diversity and relationships of a subset of 148 accessions, of which a complete passport information was available, was studied using principal components analysis (PCA), discriminant analysis of principal components (DAPC), and phylogeny approaches. C. annuum, C. baccatum, and C. chinense were successfully separated by all methods. Our population was divided into seven clusters by DAPC, where C. frutescens accessions were clustered together with C. chinense. C. annuum var. glabriusculum accessions were spread into two distinct genetic pools, while European accessions were admixed and closely related. Separation of accessions was mainly associated to differences in fruit characteristics and origin. Phylogeny studies showed a close relation between Spanish and Mexican accessions, supporting the hypothesis that the first arose from a main genetic flow from the latter. Tajima’s D statistic values were consistent with positive selection in the C. annuum clusters, possibly related to domestication or selection towards traits of interest. This work provides comprehensive and relevant information on the origin and relationships of Spanish landraces and for future association mapping studies in pepper.

Manipulation of Carotenoid Metabolic Flux by Lycopene Cyclization in Ripening Red Pepper ( Capsicum annuum var. conoides) Fruits.

Carotenoids are essential phytonutrients for the human body. Higher plants usually synthesize and accumulate carotenoids in their leaves, flowers, and fruits. Most carotenoids have either two β-rings on both ends or β- and ε-rings separately on two ends of their molecules and are synthesized from the acyclic lycopene as the precursor. Lycopene β- and ε-cyclases (LCYB and LCYE, respectively) catalyze the β- and ε-cyclization of lycopene, respectively, and regulate the metabolic flux from lycopene to its downstream β,β-branches (by LCYB alone) and β,ε-branches (by LCYE and LCYB). In this study, we identified and characterized genes for two LCYBs (CaLCYB1 and CaLCYB2), one LCYE (CaLCYE1), and a capsanthin/capsorubin synthase (CaCCS1) which is also able to β-cyclize lycopene from the red pepper ( Capsicum annuum var. conoides) genome. By quantifying transcript abundances of these genes and contents of different carotenoid components in ripening fruits, we observed a correlation between the induction of both CaLCYBs and the accumulation of carotenoids of the β,β-branch during ripening. Although capsanthin was accumulated in ripened fruits, our quantification demonstrated a strong induction of CaCCS1 at the breaker stage, together with the simultaneous repression of CaLCYE1 and the decrease of lutein content, suggesting the involvement of CaCCS1 in competing against CaLCYE1 for synthesizing carotenoids of the β,β-branch. Our results provide important information for future metabolic engineering studies to manipulate carotenoid biosynthesis and accumulation in fruits.

Benefits of organic fertilizers spray on growth quality of chili pepper seedlings under cool temperature

In this study, effects of foliar application (with constant 0.2% concentration) of chemical NPK (N20:P10:K20) and organic fertilizers of Biomin (an organic aminochelate fertilizer), Humifolin (a humic acid based fertilizer), Biomin + Humifolin, a synthetic macro-micro mixture, soil application of NPK (600 mg.kg−1 of the N20:P10:K20 formulation), and a no fertilizer control were evaluated on growth and quality of chili pepper (Capsicum annuum var annuum) seedlings under greenhouse conditions with cool temperature of 15 ± 3 °C. The results showed that most growth and quality traits were best improved by foliar application of Biomin aminochelate followed by Humifolin fertilizer. Higher values for leaf area, leaf number, chlorophyl index, root and shoot biomass, and leaf concentration of soluble sugars, N, K, Ca, and Zn, were attributed to foliar application of Biomin and Humifolin. The mixture of Biomin + Humifolin had reduced values of those parameters indicating possible negative interaction when these two organic fertilizers are mixed.

Bacterial Wilt of Sacha Inchi (Plukenetia volubilis) Caused by Ralstonia pseudosolanacearum Phylotype I in Southern China

Sacha inchi (Plukenetia volubilis L.) is a little-known yet important perennial plant native to the Andes Mountains of Peru. It is a plant producing large, edible seeds rich in omega-3 fatty acids and proteins useful for promoting human health. The economic importance of sacha inchi has increased in recent years because its seeds produce significantly higher oil yields than those of other plants (Wong 2018). Sacha inchi was first introduced to grow in Xishuangbanna, Yunnan Province, southwest China in 2006, and then to Lingshui County, Hainan Province, southern China in 2014. However, just 2 years later, in April 2016, unusual wilting was observed on many sacha inchi plants in the fields of Lingshui County. The disease outbreak proved to be rapid and extensive, covering approximately 11 ha of sacha inchi growth and causing an 80% production loss in that crop’s area in just a few months. By 2017, the farmers had almost given up on continuing sacha inchi production owing to the severity and spread of this disease. In the fields, the disease caused the plant’s stem and leaves to wilt. On seedlings, their leaves wilted and drooped while still being photosynthetically active (i.e., green), followed by total plant collapse within a few days. Mature plants initially had symptoms of irregular, black necrotic lesions at their leaf base margins. But as the disease symptoms progressed, the necrotic leaves spread upward, and eventually the affected plants turned chlorotic and shed leaves and developed black stripes on their stems. Vascular necrosis and bacterial ooze were observed when longitudinal sections were obtained from the basal portion of infected stems. For identification, a total of 10 plants with the typical wilting symptoms were collected from the sacha inchi fields of Lingshui County. Six isolates were obtained from the roots and plantlets of six separate plants. All the isolates were gram negative, oblong to rod shaped, and 0.4 to 0.9 × 0.7 to 2.0 μm in size (n = 25) when viewed under electron microscopy. When cultured on Kelman’s tetrazolium chloride medium, the colonies appeared round to oval, fluidal, and entirely white with a pale red center after incubation at 30°C for 48 h. Three Ralstonia solanacearum-specific primer pairs, for the flagella subunit (Rsol_fliC-F/ Rsol_fliC-R) (Schonfeld et al. 2003), the polygalacturonase gene (pehA #3/ pehA #6) (Gillings et al. 1993), and 759/760 (Ito et al. 1998) yielded the expected amplicons. Two representative strains (ACCC60145 plu-3 and ACCC60146 plu-6) were identified as R. pseudosolanacearum phylotype I, sequevar 34, according to the phylotype-specific multiplex polymerase chain reaction (PCR) assay (Fegan and Prior 2005) and phylogenetic analysis of the partial egl gene sequences (GenBank accession nos. KY352419 and KY352421) (Safni et al. 2014). The two strains shared 99.9 and 100% sequence identity with R. pseudosolanacearum GMI1000 (AL646052), which had been identified using 16S ribosomal RNA (GenBank accession nos. KY346975 and KY346977) sequencing and sequence comparisons. For the pathogenicity test, stems of 30 1-month-old sacha inchi (cv. Pinto Recodo) seedlings were injected with 40-μl suspensions (10⁸ CFU/ml) of the representative isolates ACCC60145 plu-3 and ACCC60146 plu-6 (10 seedlings per isolate inoculation treatment). The injection point on the seedling stem was at 2 to 3 cm above the soil surface. Symptoms of wilt were observed 5 days after these inoculations of sacha inchi. To serve as a negative control, 20 healthy sacha inchi seedlings were likewise injected but with sterile water. No disease symptoms were observed on these control plants. Reisolations were done twice, as outlined above, on the symptomatic seedlings and control plants at 3 to 4 cm above the original injection points. To complete Koch’s postulates, the bacteria were then reisolated from the inoculated sacha inchi plants and reidentified by PCR. Following the same inoculation procedure, the bacterium also caused wilting in cherry tomato (Lycopersicon esculentum Mill.; 20 of 20 individuals), eggplant (Solanum melongena L. var. esculentum Nees.; 17 of 20), and pepper (Capsicum annuum var. conoide Mill. Irish; 18 of 20). To the best of our knowledge, this is the first report of R. pseudosolanacearum phylotype I sequevar 34 causing bacterial wilt of sacha inchi in China and around the world. These disease strain findings can be useful for developing effective strategies for control of the disease in the important oil and seed plant sacha inchi.

Capsicum Chlorosis Virus: A New Viral Pathogen of Pepper in Greece

Pepper (Capsicum annuum var. annuum) is an important vegetable crop in Greece cultivated both in open fields and greenhouses on more than 4,200 ha. On the island of Crete and more specifically in Ierapetra, pepper is an economically important crop, because for the last few years a high percentage of its production has been exported. In November 2017, virus-like symptoms similar to those caused by tospoviruses were observed in a greenhouse pepper crop (cultivar Areti) in Ierapetra. The symptoms included necrotic ringspots and mottling of leaves, and they appeared in low incidence of approximately 1%. To investigate the etiology of the disease, four samples were analyzed by tomato spotted wilt virus (TSWV)-specific primers TSWVF/TSWVR (Xiao et al. 2016) for the presence of TSWV, a tospovirus endemic in Greece for more than 50 years (Chatzivassiliou et al. 1996). Because the method gave negative results, the samples were also tested by a generic reverse transcription polymerase chain reaction (RT-PCR) assay against tospoviruses using the primer set gM410/gM870c (Chen et al. 2012). A DNA band of 500 bp corresponding to the NSm gene was amplified in all symptomatic samples. Two of the obtained amplicons were directly sequenced (accession nos. LT992917 to LT992918), and further nucleotide comparison revealed that the sequences were 97% identical to the isolates Qld-3432 and Ph of capsicum chlorosis virus (CaCV) from Australia and Thailand (accession nos. KM589494 and KC953854). Therefore, the same samples were also tested with the primers CaCF/CaCR (Krishnareddy et al. 2008) and CaCL1/CaCL2 (5′-ATTTATTCTATCWGTKGCTC-3′/5′-ATTGAYCAAATAAGGCARAGTGA-3′), which amplify a DNA fragment of approximately 850 bp from the nucleocapsid (N) gene and a fragment of 828 bp from the L protein gene of CaCV, respectively, as well as with antiserum against CaCV (DSMZ AS-864). Both RT-PCR and ELISA confirmed the presence of CaCV in all tested samples, and subsequent sequencing analysis of the two previous positive isolates (accession nos. LT993065 to LT993066 and LS992237 to LS992238) revealed 98% nucleotide identity of the N gene and 96% identity of the L gene with the isolate Qld-3432 (accession nos. KM589495 and KM589493). Mechanical inoculation of 10 plants each of cultivars Arlequin and Dovras using tissue from symptomatic pepper plants reproduced the original symptoms. Four to five weeks postinoculation, ringspots and mottling started to appear at the upper part in some of the pepper plants, whereas no symptoms appeared on noninoculated control plants. RT-PCR verified the presence of CaCV in 3 of 10 Arlequin and in 1 of 10 Dovras pepper plants. CaCV was initially reported in Australia (McMichael et al. 2002) and then in different countries of Asia and in Hoya calycina in Hawaii. To our knowledge, this is the first report of CaCV in this area and highlights its potential as a threat for pepper production in Greece and the Mediterranean basin. Even though so far its incidence is low, extensive surveys in other regions are required to unravel the spread of this new pathogen in pepper and other crops in Greece.

Candidate markers assay for Capsicum pungency

Effectiveness of candidate markers for differentiating the pungent, slightly pungent and non-pungent chilli lines and their use in marker assisted selection programmes was assessed. Two pungent C. annuum, one pungent C. chinense, two pungent C. frutescens, one non-pungent C. annuum, two non-pungent C. annuum var. grossum and two slightly pungent C. annuum var. acuminatum cultivars were analysed using MAP1 marker for locus Pun1, CS and B markers for locus CS, Pun11 marker for locus Pun1 of C. annuum and Pun13 marker for locus Pun1 of C. frutescens. This paper discusses the universal suitability of these candidate markers in MAS programmes for levels of pungency in Capsicum. Through sequencing of markers it is further shown that the proposed CS gene lies within the Pun1 locus and since Pun1 markers are missing in non-pungent and slightly pungent lines, we propose that genes other than Pun1 are involved in pungency mechanism in Capsicum spp.

The effectiveness of vegetable oil formulations in reducing oviposition of Bactrocera dorsalis Hendel (Diptera: Tephritidae) in large red chili fruits

Chili peppers (Capsicum annuum), in their many varieties, constitute a culturally and economically important horticultural crop in a number of countries. The Indonesian cayenne large red chili (Capsicum annuum var. annuum) is used widely in Indonesia mainly in cooking. There have been reports of increased infestation of large red chili by insect pests, particularly fruit flies. The aim of this study was to investigate the effectiveness of five edible vegetable oils (palm oil, coconut oil, soybean oil, corn oil, and candlenut oil) and one non-edible vegetable oil (neem oil) in reducing landings, oviposition, and infestation by the Oriental fruit fly (Bactrocera dorsalis Hendel) in large red chili fruits. This lab-based experiment entailed exposure of large red chili fruits to 20 mature B. dorsalis females (14–21 days old) inside a 15-l plastic container. Six separate containers each held 10 large red chili fruits with a single oil treatment in each. Prior to exposure, each of the treated and control large red chili fruits was punctured once with a needle in order to create an opening for oviposition. Results indicate that the coconut oil formulation was most effective in preventing damage from B. dorsalis females, and reducing fruit fly landings, oviposition, and infestation.

Deterioro de la calidad de la semilla de chile piquín de cuatro colectas de Querétaro y Guanajuato (Capsicum annuum var. Aviculare)

El objetivo de la presente investigación fue evaluar la calidad de semilla de chile piquín a través de la prueba de envejecimiento acelerado en colectas de chile piquín (Capsicum annuum var. Aviculare) del estado de Querétaro y Guanajuato. Las colectas se realizaron en cuatro localidades El Patol, El Cuervo e Higuerillas del municipio de Querétaro y El Tanque del municipio de Xichú. El vigor de la semilla se obtuvo mediante la prueba de envejecimiento acelerado que consistió en someter las semillas 24, 48, 72, 96, 120 y 144 h a una temperatura de 42 °C y 100% de humedad relativa, después de este periodo, las semillas se someten a una prueba normal de germinación a los 7, 14 y 21 días. Los resultados en el análisis de varianza expresaron efecto significativo en genotipos, siendo el mejor tiempo para el conteo realizado a los 7 días y a las 24 h. A los 14 días los mejores tiempos fue para el testigo las cero, 24 h, 48 h y 72 h. Por otro lado, se registró la calidad de la semilla, las cuales presentaron diferencias significativas para peso seco de vástago, los valores más altos fueron para El Tanque y El Patol. En peso seco de raíz, peso de cien semillas y velocidad de emergencia destacan las colectas provenientes de El Tanque, El Patol y El Cuervo. Higuerillas presentó valores más bajos en los caracteres antes indicados, diferencia que podría atribuirse a las condiciones ambientales.