Activation of defence in sweet pepper, Capsicum annum, by cis-jasmone, and its impact on aphid and aphid parasitoid behaviour

BACKGROUND: Two important pests of the sweet pepper, Capsicum annuum, are the peach potato aphid, Myzus persicae, and the glasshouse potato aphid, Aulacorthum solani. Current aphid control measures include the use of biological control agents, i.e. parasitic wasps, but with varying levels of success. One option to increase parasitoid efficiency is to activate plant defence. Therefore, sweet pepper plants were treated with the naturally occurring plant defence activator cis-jasmone, and its impact upon the behaviour and development of aphids and aphid parasitoids was investigated. RESULTS: Growth rate studies revealed that the intrinsic rate of population increase of A. solani and M. persicae on sweet pepper plants treated with cis-jasmone (cJSP) was not affected compared with untreated plants (UnSP), but the positive behavioural response of alate M. persicae towards the volatile organic compounds (VOCs) from UnSP was eliminated by cis-jasmone treatment 48 h previously (cJSP48). In addition, the aphid parasitoid Aphidius ervi preferred VOCs from cJSP48 compared with UnSP, and a significant increase in foraging time was also observed on cJSP. Analysis of VOCs collected from cJSP48 revealed differences compared with UnSP. CONCLUSION: There is evidence that treatment with cis-jasmone has the potential to improve protection of sweet pepper against insect pests. © Crown copyright 2012. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.     

Corynespora blight of sweet pepper (<Emphasis Type="Italic">Capsicum annuum</Emphasis>) caused by <Emphasis Type="Italic">Corynespora cassiicola</Emphasis> (Berk. &; Curt.) Wei

In 2004, Corynesopra cassiicola was isolated from dark brown spots on leaves and fruits and from black blights on stems of sweet pepper plants in Kochi Prefecture, Japan. The isolated fungus was then used to inoculate sweet pepper plants and subsequently reisolated from the plants with dark brown spots and black blights, showing that C. cassiicola is a new pathogen causing Corynespora blight on sweet pepper plants. The nucleotide sequence data reported are available in the DDBJ/EMBL/GenBank databases as accession numbers AB366649 (TS-C11), AB366650 (TS-C21), AB366651 (TI-C32) and AB366652 (TI-C51)     

Differential reaction of sweet pepper to infection with the crinivirus tomato chlorosis virus probably depends on the viral variant

The tomato chlorosis virus (ToCV), transmitted by whitefly species of the genera Bemisia and Trialeurodes in a semipersistent manner, causes significant losses in solanaceous crops including tomato (Solanum lycopersicum) and sweet pepper (Capsicum annuum). Worldwide reports of natural and experimental infection of sweet pepper plants with ToCV are contradictory, raising the question of whether the critical factor determining infection is related to the susceptibility of sweet pepper cultivars or the genetics of virus isolates. In this work, ToCV isolates obtained from different hosts and geographical origins were biologically and molecularly analysed, transmitted by B. tabaci MEAM1 and MED, and the reaction of different sweet pepper cultivars was evaluated under different environmental conditions. Brazilian ToCV isolates from tomato, potato (S. tuberosum), S. americanum, and Physalis angulata did not infect plants of five sweet pepper cultivars when transmitted by B. tabaci MEAM1. Temperatures did not affect the sweet pepper susceptibility to tomato-ToCV isolates from São Paulo, Brazil, and Florida, USA. However, sweet pepper-ToCV isolates from Spain and São Paulo, Brazil, were transmitted efficiently to sweet pepper plants by B. tabaci MEAM1 and MED. Although the results indicated that ToCV isolates from naturally infected sweet pepper plants seem to be better adapted to plants of C. annuum, phylogenetic analyses based on the complete nucleotide sequences of RNA1 and RNA2 as well as the p22 gene did not reveal significant nucleotide differences among them. Additional studies are needed to identify intrinsic characteristics of ToCV isolates that favour infection of sweet pepper plants.     

Plant food effects on prey consumption by the omnivorous predator Macrolophus pygmaeus

Omnivorous predatory Heteroptera are important biological control agents of pests in several crops. They can feed on plant food resources that may positively affect their biological characteristics. In the current paper, the influence of leaves and flowers on the predation rate of the omnivorous predator Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae) was investigated. Its predation rates were recorded on prey offered on (a) a single leaf of tomato, pepper or black nightshade (Solanum nigrum), or (b) a leaf of pepper or S. nigrum plus flowers of pepper or S. nigrum, respectively. In all cases the aphid Myzus persicae (Sulzer) (Homoptera: Aphididae) was used as prey at densities of 4, 8, 12, 16, 20 and 24 nymphs of the second instar. The experiments were conducted in petri dishes at 25 ± 1°C and prey consumption was evaluated after 24 h. The predation rate of M. pygmaeus was significantly higher on leaves of S. nigrum than on those of pepper at the prey density of 20 prey items. Therefore, the hypothesis that increased predation rates should occur on plants of lower suitability for development or reproduction was not supported under our experimental conditions. The flower availability did not alter the prey consumption among the prey densities on S. nigrum. However, the presence of a pepper flower caused a significant decrease in the predation rates on pepper leaves, at prey densities higher than eight prey items. Thus, pepper flowers can provide the predator with nutrient sources that may partially substitute for prey consumption, with practical implications in biological control.     

大草蛉幼虫对不同寄主植物上烟粉虱卵的捕食功能反应与搜寻效应

为了研究不同寄主上大草蛉Chrysopa pallens(Rambur)幼虫对烟粉虱Bemisia tabaci(Gennadius)卵的捕食功能反应与搜寻效应,在室内条件下评估了大草蛉捕食功能反应模型,并研究了大草蛉3龄幼虫对棉花、烟草和辣椒上烟粉虱卵的搜寻效应和控害潜能。结果显示,在3种寄主植物上大草蛉3龄幼虫捕食量均随猎物密度的增加而升高,在烟草、棉花、辣椒上的捕食量分别为7.6~28.4、5.4~23.2、6.0~18.8粒;3种寄主植物上的大草蛉捕食功能反应均拟合Holling II、III功能反应模型;在烟草上大草蛉的瞬间攻击率最大,为0.470,处理时间最短,为0.021;在3种寄主植物上大草蛉3龄幼虫搜寻效应均随猎物密度的增加而下降,当猎物密度相同时,在烟草上的搜寻效应高于棉花和辣椒。研究表明,不同寄主植物能够影响大草蛉3龄幼虫对烟粉虱卵的瞬间攻击率及其搜寻效应。     

Biology and behaviour of Ephestiasula pictipes (Wood-Mason) (Hymenopodidae: Mantodea) under captive breeding

The biology and behaviour of a common predator in cashew plantations, Ephestiasula pictipes (Wood-Mason), were studied under captivity for three seasons using greater wax moth larvae as prey. During Feb–May, incubation and nymphal developmental period were shorter when compared with Jun–Sep and Oct–Jan. The female mantids laid ootheca once in every 3–4 days, for a period of 70–77 days. Adult longevity and oviposition period were significantly higher during Feb–May, while no significant difference was observed in sex ratio, oviposition interval and pre oviposition period during different seasons. Sexual behaviour consisted of preliminary courtship and copulation, involving 14 activities in sequence. Duration of mounting, copulation and riding around on the female by the male widely varied from 2 min to 28 h; 5.15 to 6.10 h; and 2 to 74 h, respectively. High fertility, high fecundity, shorter life cycle, multivoltinism and feasibility of laboratory rearing throughout the year are the advantageous features of E. pictipes that permits for its mass rearing and emergence as a viable biocontrol agent in future.     

Mitigation of Salt Stress Negative Effects on Sweet Pepper Using Arbuscular Mycorrhizal Fungi (AMF), <Emphasis Type="Italic">Bacillus megaterium</Emphasis> and Brassinosteroids (BRs)

A study was conducted at the experimental farm of Faculty of Agriculture, Ain Shams University, Cairo, Egypt, during two successive summer seasons (2014 and 2015) to investigate the effects of arbuscular mycorrhizal fungi (Glomus irradicans 10% w/w), Bacillus megaterium (10?ml/pot) and brassinosteroids (24-EBL, C₂₈H₄₈O_6; 2?µM) on growth, nutrient absorption, chlorophyll, proline content, antioxidant enzymes activity and fruit yield of sweet pepper plants (Capsicum annuum L.) cv. Marconi. Plants were grown under three levels of salinity (0, 25 and 50?mM). The obtained results showed that plants grown under non-saline water (0?mM NaCl), with or without treatments, significantly gave the most vigorous vegetative growth and had the highest fruit yield compared with those grown under salt stress conditions. All anti-salinity treatments (Mycorrhiza, Bacillus and Brassinosteroids) improved growth when compared with untreated plants (control). Plants inoculated with mycorrhiza or treated with brassinosteroids showed better vegetative growth and shoot biomass (total fresh and dry weight per plant), chlorophyll a and b concentrations, antioxidant content expressed as total soluble phenols and proline concentrations at all studied salinity levels followed by plants inoculated with Bacillus megaterium compared with control plants which showed severe growth retardant especially under higher salt concentration (50?mM). Carotenoids concentration increased proportionally with the increase of salinity concentration. The maximum leaf relative water content (LRWC) and lowest values of membrane permeability (MP) were significantly observed with mychorhiza inoculated plants and brassinosteroid application respectively, followed by Bacillus inoculated plants. Antioxidant enzyme activity were highest in plants irrigated with moderate saline water (25?mM) than plants under high salinity irrigation water (50?mM) except polyphenol oxidase (PPO) as compared with unstressed plants (0?mM). Mycorrhizal inoculated plants accumulated higher K and lower Na and Cl followed by plants treated with brassinosteroids and then plants inoculated with Bacillus megaterium. Anti-salinity treatments positively enhanced fruit yield of sweet pepper plants under all salinity stress levels and the highest fruit yield were significantly observed with brassinosteroid application followed by mychorhiza inoculated plants and then Bacillus inoculated plants.     

短翅蚜小蜂对桃蚜的取食和寄生功能反应

为评估短翅蚜小蜂对桃蚜的搜寻及控害潜能,采用叶碟法研究了短翅蚜小蜂对甘蓝和辣椒2种植物上桃蚜2龄若虫的取食与寄生行为。结果表明,短翅蚜小蜂对甘蓝桃蚜和辣椒桃蚜的取食和寄生功能反应均符合Holling II及Holling III型方程。短翅蚜小蜂的取食和寄生搜寻效应均随蚜虫密度的增加而降低,当桃蚜密度小于35头时,短翅蚜小蜂对甘蓝桃蚜的取食搜寻效应大于辣椒桃蚜,而当桃蚜密度大于35头时,短翅蚜小蜂对辣椒桃蚜的取食搜寻效应大于甘蓝桃蚜;短翅蚜小蜂在所有密度下对辣椒桃蚜的寄生搜寻效应均大于甘蓝桃蚜。短翅蚜小蜂取食甘蓝桃蚜的瞬间攻击率a'为0.3289,处理时间T_h为0.2597,均大于辣椒桃蚜,寄生甘蓝桃蚜的瞬时攻击率a'为0.8213,小于辣椒桃蚜,而处理时间T_h为0.0275,大于寄生辣椒桃蚜;短翅蚜小蜂对甘蓝桃蚜的理论最大取食量和寄生量均小于辣椒桃蚜。研究表明,短翅蚜小蜂对不同密度的桃蚜均有一定的控制能力,且对辣椒桃蚜的控制作用大于甘蓝桃蚜。     

Response of a red clone of Myzus persicae (Hemiptera: Aphididae) to sublethal concentrations of imidacloprid in the laboratory and greenhouse

BACKGROUND: Pest resurgence following a pesticide application may occur owing to a stimulatory (hormetic) response to sublethal insecticide concentrations. The objective of the present study was to examine the potential for a greenhouse‐derived red clone of Myzus persicae to exhibit resurgence owing to a hormetic response following a systemic imidacloprid treatment in a bell pepper greenhouse. RESULTS: No differences in mortality and fecundity were observed among apterous adults exposed to sublethal imidacloprid concentrations on excised pepper leaves fed aqueous solutions of imidacloprid. Survival of first‐generation progeny was negatively affected by imidacloprid exposure, yet surviving progeny exhibited no differences in development rates or fecundity from progeny of adults unexposed to imidacloprid. Aphid mortality declined most rapidly in clip cages on pepper leaves at the top of the pepper canopy as compared with leaves present at the middle or bottom of the pepper canopy. CONCLUSION: Imidacloprid decays rapidly in mature pepper plants, resulting in sublethal concentrations in the upper canopy in as little as 4 weeks. Sublethal insecticide concentrations have been implicated in the resurgence of pest populations; however, exposure to sublethal doses of imidacloprid are unlikely to result in pesticide‐induced resurgence of the M. persicae aphid clone examined in this study. Copyright © 2011 Society of Chemical Industry     

Biological and molecular characterization of tomato spotted wilt virus (TSWV) resistance-breaking isolates from Argentina

Tomato spotted wilt virus (TSWV) has been present in Argentina since 1938 and had limited sweet pepper and tomato production until the introduction of resistant cultivars bearing Tsw and Sw-5b genes. However, the wide use of TSWV-resistant pepper plants in La Plata Horticultural Belt (LPHB) triggered the emergence of resistance-breaking isolates (RB), increasing the economic impact of TSWV in pepper. This work characterized 11 natural RB pepper isolates from LPHB that have overcome the Tsw resistance gene in Capsicum sp. but are unable to break the Sw-5b-mediated resistance in tomato. Phylogenetic analysis of the N gene showed that the LPHB isolates are most closely related to isolates from Asia, indicating that Argentine TSWV isolates might have emerged from the Asian continent. The NSs sequence analysis reinforces the hypothesis that the appearance of an RB phenotype is a consequence of a number of different single amino acid substitutions spread along the NSs gene that lead to multiple independent evolutionary events. These results provide information on the current situation of the tospovirus–pepper/tomato pathosystems in LPHB, which represents a fundamental prerequisite to include these RB isolates in future screening programmes in order to select new and durable sources of resistance to TSWV in pepper.     

Effect of temperature on predation of Chilocorus bipustulatus L. (Col.: Coccinellidae) feeding on Agonoscena pistaciae (Hem.: Psyllidae)

Chilocorus bipustulatus L. (Col.: Coccinellidae) is a predatory coccinellid with a wide geographical distribution. Biological control programs should have a good understanding of the capacity of a predator to kill the target prey. Therefore, the age-stage specific predation rate and functional response of C. bipustulatus feeding on Agonoscena pistaciae (Hem.: Psyllidae) were studied at 18, 25, and 32 °C (65?±?5%RH and 16 L: 8D) to confirm its potential as a biological control agent of common pistachio psylla. The functional response at 18 and 25 °C were described by type II and type III at 32 °C. The estimated maximum attack rate (T/Th) was at 25 °C. Moreover, the highest net feeding (C₀) was observed at 25 °C (3271.5 psyllids). This laboratory study, thus, suggested that the predatory coccinellid C. bipustulatus reacted to the rise of temperature by enhancing the predation rate on A. pistaciae.

     

PM 7/110 (1) Xanthomonas spp. (Xanthomonas euvesicatoria,Xanthomonas gardneri,Xanthomonas perforans,Xanthomonas vesicatoria) causing bacterial spot of tomato and sweet pepper

Specific scope

This standard describes a diagnostic protocol for Xanthomonas spp. causing bacterial spot of tomato and sweet pepper (Xanthomonas euvesicatoria, Xanthomonas gardneri, Xanthomonas perforans, Xanthomonas vesicatoria) ¹ .

Specific approval and amendment

Approved in 2012–09.     

Life-table analyses for the tomato leaf miner,Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae): effects of plant genotype

BACKGROUND

Host plant resistance plays an important role in integrated pest management programs. Crop resistance assessments commonly focus on only a single dependent variable, such as larval survival/plant damage, which limits the ability to appreciate the impact of host plants on pest populations in the full sense. Therefore, we performed life-table analyses for tomato leaf miner Tuta absoluta, on 19 Solanum lycopersicum genotypes and a wild Solanum habrochaites accession. These analyses assess the ability of the pest to attain a high population density on different tomato genotypes. Based on the resulting ranking of tomato resistance at the vegetative stage (45-day-old plants), we tested the resistance of six selected genotypes at the reproductive stage (4-month-old plants).

RESULTS

T. absoluta performance was significantly inferior on vegetative-stage S. habrochaites plants (LA 1777); time taken for the first instars to mine the leaves (5 ± 0.14 days), development time of early- and late-stage larvae (8.8 ± 0.2 and 4.2 ± 0.2 days, respectively), pupal period (11.2 ± 0.58 days), and total developmental time (29.4 ± 0.83 days) were significantly longer, fecundity was significantly lower (18.66 ± 7.24 days), and the highest total mortality (63.33%) also recorded compared with other genotypes, resulting in the lowest net reproductive rate (R₀) (11.20 ± 2.51). For the six selected genotypes, the ranking of plant resistance did not change between plants at the vegetative and reproductive stages.

CONCLUSION

This study suggested that of 20 screened tomato genotypes, LA 1777 and EC-620343 are the least suitable hosts for T. absoluta to establish fast-growing populations, and thus can be employed in integrated T. absoluta management. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Helicoverpa armigera preference and performance on three cultivars of short-duration pigeonpea (Cajanus cajan): the importance of whole plant assays

BACKGROUND

Helicoverpa armigera is a major pest of pigeonpea (Cajanus cajan). Efforts to develop pigeonpea varieties resistant to H. armigera attack have been met with limited success, despite reports of high levels of resistance to H. armigera in wild relatives of pigeonpea and reports of low to moderate levels of resistance in cultivated varieties. Here we examined H. armigera oviposition preference and larval performance on whole plants of three cultivars of short-duration pigeonpea: a susceptible control (ICPL 87) and two cultivars with purported host–plant resistance (ICPL 86012 and ICPL 88039).

RESULTS

In our no-choice oviposition experiment, H. armigera laid similar numbers of eggs on all three cultivars tested, but under choice conditions moths laid slightly more eggs on ICPL 88039. Larval growth and development were affected by cultivar, and larvae grew to the largest size (weight) and developed fastest on ICPL 86012. Moths laid most of their eggs on floral structures, sites where subsequent early instar larvae overwhelmingly fed. Experimentally placing neonate larvae at different locations on plants demonstrated that larvae placed on flowers experienced greater survival, faster development, and greater weight gain than those placed on leaves. The type and density of trichomes (a potential resistance trait) differed among cultivars and plant structures, but larvae selected to feed at sites where trichomes were absent.

CONCLUSION

Future work examining host–plant resistance against H. armigera should incorporate the behavioural preference of moths and larvae in experiments using whole plants as opposed to bioassays of excised plant parts in Petri dishes. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Pathogenic and genetic variation among isolates of Corynespora cassiicola in Japan

In order to develop a method for discrimination of Corynespora cassiicola isolates pathogenic to sweet pepper among Japanese isolates, this study analysed pathogenic variations of 64 Japanese isolates of C. cassiicola on perilla, cucumber, tomato, aubergine and sweet pepper, and their multigene phylogeny. Japanese isolates were divided into seven pathogenicity groups (PG1–PG7). The virulence of isolates in PG1–PG5 was restricted to perilla, cucumber, tomato, aubergine and sweet pepper, respectively. Isolates in PG6 were virulent to sweet pepper, tomato and aubergine. Isolates in PG7 were avirulent to all tested plants. Multigene phylogenetic analysis of the isolates based on β‐tubulin, translation elongation factor 1‐α, calmodulin and actin genes showed three divergent clusters, MP‐A, MP‐B and MP‐C. These clusters included all isolates in PG1, PG2, PG8 and PG9 (MP‐A), PG3 and PG5 (MP‐B) and PG4 and PG6 (MP‐C). Isolates in PG7 were distributed amongst all clusters. Furthermore, random amplified polymorphic DNA (RAPD) analysis using universal primers, Q17 (5′‐GAAGCCCTTG‐3′) and Q13 (5′‐GGAGTGGACA‐3′), facilitated discrimination of isolates virulent on sweet pepper amongst isolates in MP‐B and MP‐C, respectively. Together, a combination of the multigene analysis and the RAPD technique allowed the discrimination of the isolates virulent to sweet pepper.     

Field trial measuring the compatibility of methoxyfenozide and flonicamid with Orius laevigatus Fieber (Hemiptera: Anthocoridae) and Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) in a commercial pepper greenhouse

BACKGROUND: Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) are among the most serious pests of sweet peppers in greenhouses. Chemical control is difficult because of their high reproductive rates and insecticide resistance, and seasonal inoculative releases of Orius laevigatus (Fieber) and Amblyseius swirskii (Athias‐Henriot) are commonly used to reduce their populations. As chemical treatments are often needed in the crop against other pests, the side effects of methoxyfenozide (an insect growth regulator against lepidopteran pests) and flonicamid (a selective feeding inhibitor against sucking insects) were studied in both beneficial organisms in a commercial greenhouse. RESULTS: Orius laevigatus and A. swirskii were released at commercial rates (4–5 and 100 m^?2), and a strong establishment and a very homogeneous distribution were reached. One pesticide treatment with the maximum field recommended concentration of methoxyfenozide and flonicamid (96 and 100 mg AI L^?1) was done when they were well established, and their population levels were not affected either immediately or up to 30 days after treatment. CONCLUSION: The results are indicative of no impact of methoxyfenozide and flonicamid on the two natural enemies in the field, and both can be considered as potential alternatives to be included in IPM programmes in sweet pepper. Copyright © 2011 Society of Chemical Industry     

Comparative life history characteristics of the mite predator Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) on mite and pollen diets

The food diversification strategy that can offer suitable nutrients as a diet for the natural enemies may possibly help to decrease pest populations by boosting the efficiency of predators. Therefore, my objective was to evaluate the effects of plant and animal diets on biological parameters of the phytoseiid mite Neoseiulus cucumeris (Oudemans). This predator that is a natural enemy of mites was reared on plant pollens (maize (Zea mays L.), sweet pepper (Capsicum annuum L.), mungbean (Vigna radiata L.), cucumber (Cucumis sativus L.), tomato (Lycopersicon esculentum Mill.), and rose (Rosa multiflora Thunb.), offered alone, and in combination with the prey mite Tyrophagus putrescentiae (Schrank). Results showed that N. cucumeris fed, developed and reproduced better when it was provided with plant and animal diets together, compared to pollens offered alone. The predator showed the most efficient capability for completion of life parameters (development, survival, fecundity, oviposition, longevity and instantaneous rate of increase) with maize and mungbean ingested pollens in combination with T. putrescentiae. The least competency was observed on cucumber and rose pollens used separately. The lowest developmental time of the predator from neonate larva to adult emergence, the highest immature survivorship, higher fecundity, long oviposition period, and the highest adult female's life span were observed when offered maize pollens along with T. putrescentiae compared to other treatments. Accordingly, the instantaneous rate of population increase (r_i) day^?1 was surpassed by N. cucumeris for the combination of pollen and T. putrescentiae diets than pollens utilized alone. It is determined that N. cucumeris can reproduce and develop more successfully on a food complex consisting of pollen and animal diets than any single diet. These findings reveal that pollen can be used by N. cucumeris as a suitable alternative food in periods when prey in the field is sparse or absent. Moreover, such propensity of predators to feed on food from plant origin increases their survival during periods when prey is locally scarce, but natural enemies might occur at the expense of an ability to utilize food as efficiently as specialized predators to boost the management strategies of pest species in field's ecosystem.     

Tomato chlorosis virus in pepper: prevalence in commercial crops in southeastern Spain and symptomatology under experimental conditions

Tomato chlorosis virus (ToCV), a member of the genus Crinivirus (family Closteroviridae), has been present in Spain since at least 1997, causing annual epidemics of yellowing in protected tomato crops. In 1999, sweet pepper plants exhibiting stunting and symptoms of interveinal yellowing and mild upward curling in the leaves, were found to be infected with ToCV in a greenhouse heavily infested with the whitefly Bemisia tabaci in the province of Almería, southeastern Spain. This study investigated the prevalence of ToCV in tomato and pepper crops in the major growing areas of southeastern Spain (Murcia, Almería and Málaga provinces) over a 3‐year period. In addition, an experimental system was developed for ToCV inoculation using B. tabaci as a vector, which allowed analysis of susceptibility of different pepper cultivars to the virus. The disease syndrome and yield losses induced by ToCV in pepper were also studied under experimental conditions, confirming severe yield reduction in infected plants.     

First report of Moroccan pepper virus on lisianthus (Eustoma grandiflorum) in Japan

In sap from plants of lisianthus (Eustoma grandiflorum) with necrotic stunt symptoms in Yamaguchi Prefecture in Japan, spherical particles with a diameter of about 30 nm were observed with transmission electron microscopy. We sequenced the complete genome of an isolate using the tombusvirus-specific primers and found that it shared about 96 % nucleotide identities with Moroccan pepper virus (MPV) in the genus Tombusvirus. The isolate reproduced necrotic stunt symptoms on lisianthus plants after mechanical inoculation. This is the first report of MPV on lisianthus in Japan.     

Endophytes of <Emphasis Type="Italic">Lippia citriodora</Emphasis> (Syn. <Emphasis Type="Italic">Aloysia triphylla</Emphasis>) enhance its growth and antioxidant activity

Sweet pepper (Capsicum annuum) is a popular crop worldwide and an asymptomatic host of the begomovirus (Geminiviridae) Tomato yellow leaf curl virus (TYLCV). A previous study showed that TYLCV could be transmitted by the seeds of tomato plants, but this phenomenon has not been confirmed in other plants. In 2015, four different cultivars of sweet pepper (‘Super Yellow,’ ‘Super Red,’ ‘Sunnyez’ and ‘Cupra’) known to be susceptible to TYLCV were agro-inoculated with a TYLCV infectious clone. Three months after inoculation, the leaves of the ‘Super Yellow’ cultivar showed 80% (8/10) susceptibility and the other three sweet pepper cultivars showed 30 to 50% susceptibilities. All of the ‘Super Yellow’ seed bunches (five seeds per bunch) from plants whose leaves were confirmed to be TYLCV-infected were also TYLCV-infected (8/8). The seeds of other cultivars showed 20 to 40% susceptibilities. Virus transmission rates were also verified with 10 bunches of seedlings for each cultivar (five seedlings per pool). Eight bunches of ‘Super Yellow’ seedlings (8/10) were confirmed to be TYLCV-infected and one to three bunches of each of the other cultivar seedlings were also infected. Viral replication in TYLCV-infected seeds and seedlings was confirmed via strand-specific amplification using virion-sense- and complementary-sense-specific primer sets. This is the first report of TYLCV seed transmission in sweet pepper plants and among non-tomato plants. Because sweet pepper is an asymptomatic host of TYLCV, seeds infected with TYLCV could act as a silent invader of tomatoes and other crops.