Occurrence of Helicoverpa armigera (Hübner, 1808) on citrus in the state of Sao Paulo, Brazil

The occurrence of Helicoverpa armigera (Hübner, 1808) was first reported in citrus orchard in the state of São Paulo (SP). High infestation levels of H. armigera were observed in October 2012, in the city of Botucatu, SP. The larvae was fed of all parts of the plants. The injuries on the leaves caused drastic reduction in the leaf area and the fruits attack occurred from an early stage of development to the ripe fruit. Thus, the first occurrence of H. armigera in this citrus culture adds to the list of hosts of this pest, and is of great importance, because it confirms H. armigera potential dispersion and polyphagia.

An isolate of Apple stem grooving virus associated with Cleopatra mandarin fruit intumescence

A citrus tatter leaf isolate (CTLV-Cl) of Apple stem grooving virus (ASGV) has been found to be associated with a fruit rind intumescence in Cleopatra mandarin (Citrus reshni) in Limeira (SP). The CTLV-Cl was mechanically transmitted to the main experimental herbaceous hosts of CTLV. Chenopodium quinoa and C. amaranticolor reacted with local lesions and systemic symptoms while other test plants reacted somewhat differently than what is reported for CTLV. A pair of primers designed for specific detection of ASGV and CTLV amplified the expected 801 bp fragment from the CTLV-Cl-infected plants. Typical capillovirus-like particles were observed by the electron microscope in experimentally infected C. quinoa and C. amaranticolor leaves.

Stability of Citrus tristeza virus protective isolate 'Pêra IAC' according to SSCP analysis of old and new lines of three sweet orange varieties

Clonal cleaning, followed by pre-immunization with protective complexes of Citrus tristeza virus(CTV), allowed the commercial cultivation of Pêra sweet orange, a variety that has great importance for Brazilian citriculture but is sensitive to the virus. The use of mild protective isolates in other citrus varieties, even those more tolerant to CTV, can also be of interest to prevent the spread of severe isolates. The aim of this study was to characterize, by means of SSCP (Single Strand Conformational Polymorphism) analysis of the coat protein gene, CTV isolates present in plants of the sweet orange cultivars Pêra, Hamlin and Valencia propagated from four budwood sources: 1) old lines, 2) nucellar lines, 3) shoot-tip-grafted lines, and 4) shoot-tip-grafted lines pre-immunized with the mild CTV protective isolate 'PIAC'. We also evaluated the correlation of the obtained SSCP patterns to stem pitting intensity, tree vigor and fruit yield. SSCP results showed low genetic diversity among the isolates present in different trees of the same variety and same budwood source and, in some cases, in different budwood sources and varieties. Considering tristeza symptoms, lower intensity was noted for plants of new, shoot-tip-grafted and pre-immunized shoot-tip-grafted lines, compared to old lines of the three varieties. The observed SSCP patterns and symptomatology suggested that more severe CTV complexes infect the plants of old lines of all three varieties. The protective complex stability was observed in the SSCP patterns of CTV isolates of some shoot-tip-grafted and pre-immunized clones. It was concluded that the changes detected in other electrophoretic profiles of this treatment did not cause loss of the protective capacity of CTV isolate 'PIAC' inoculated in the pre-immunization.

Nutritional value of organic acid lime juice (Citrus latifolia T.), cv. Tahiti

Acid lime can be used as fresh fruit or as juice to increase the flavor of drinks. Therefore, it is necessary to analyze organic acid lime nutritional composition in order to evaluate if there are important differences among those conventionally produced. No significant differences in total titrable acidity, pH, ascorbic acid, sucrose, calcium, and zinc were found between the acid lime juice from organic biodynamic crops and conventional crops. However, the organic biodynamic fruits presented higher peel percentage than the conventional ones leading to lower juice yield. On the other hand, fructose, glucose, total soluble solids contents, potassium, manganese, iron, and copper were higher in the conventional samples. These results indicated few nutritional differences between organic and conventional acid lime juices in some constituents. Nevertheless, fruit juice from biodynamic crops could be a good choice since it is free from pesticides and other agents that cause problems to human health maintaining the levels similar to those of important nutritional compounds.

Physicochemical and microbiological characteristics of minimally processed 'Champagne' oranges (Citrus reticulata × Citrus sinensis) in different packgings

The objective of this study was to investigate the influence of the level of minimal processing and modified atmosphere on the quality of 'Champagne' orange stored under refrigeration. The fruits were subjected to the following processing: a) whole fruit without flavedo; b) whole fruit without flavedo and albedo; and c) segmented into wedges and packed as follows: uncoated packaging (control); polyethylene film; PVC film; gelatin-based edible films (3%); and polyesthyrene translucent plastic container with a lid. The minimally processed oranges were stored at 5 ± 1°C for 8 days and were subjected to physicochemical and microbiological analyses every two days. Greater weight loss occurred in fruits without flavedo and segmented, uncoated, and coated with the edible gelatin film During storage, there was a slight increase in Total Soluble Solids (TSS) for the treatments with greater weight loss and reduction in acidity and ascorbic acid, regardless of the packaging type. The microbial counts did not exceed the acceptable limits in the treatments; however, higher counts were observed at the end of storage. The minimally processed fruit packed in lidded polystyrene containers and polyethylene and PVC films kept their overall fresh visual appearance with a few physicochemical and microbiological changes up to the 8th day of storage.

The impact of fruit flavonoids on memory and cognition

There is intense interest in the studies related to the potential of phytochemical-rich foods to prevent age-related neurodegeneration and cognitive decline. Recent evidence has indicated that a group of plant-derived compounds known as flavonoids may exert particularly powerful actions on mammalian cognition and may reverse age-related declines in memory and learning. In particular, evidence suggests that foods rich in three specific flavonoid sub-groups, the flavanols, anthocyanins and/or flavanones, possess the greatest potential to act on the cognitive processes. This review will highlight the evidence for the actions of such flavonoids, found most commonly in fruits, such as apples, berries and citrus, on cognitive behaviour and the underlying cellular architecture. Although the precise mechanisms by which these flavonoids act within the brain remain unresolved, the present review focuses on their ability to protect vulnerable neurons and enhance the function of existing neuronal structures, two processes known to be influenced by flavonoids and also known to underpin neuro-cognitive function. Most notably, we discuss their selective interactions with protein kinase and lipid kinase signalling cascades (i.e. phosphoinositide-3 kinase/Akt and mitogen-activated protein kinase pathways), which regulate transcription factors and gene expression involved in both synaptic plasticity and cerebrovascular blood flow. Overall, the review attempts to provide an initial insight into the potential impact of regular flavonoid-rich fruit consumption on normal or abnormal deteriorations in cognitive performance.

Proteomic analysis reveals suppression of bark chitinases and proteinase inhibitors in citrus plants affected by the citrus sudden death disease

Citrus sudden death (CSD) is a disease of unknown etiology that greatly affects sweet oranges grafted on Rangpur lime rootstock, the most important rootstock in Brazilian citriculture. We performed a proteomic analysis to generate information related to this plant pathogen interaction. Protein profiles from healthy, CSD-affected and CSD-tolerant stem barks, were generated using two-dimensional gel electrophoresis. The protein spots were well distributed over a pI range of 3.26 to 9.97 and a molecular weight (MW) range from 7.1 to 120 kDa. The patterns of expressed proteins on 2-DE gels made it possible to distinguish healthy barks from CSD-affected barks. Protein spots with MW around 30 kDa and pI values ranging from 4.5 to 5.2 were down-regulated in the CSD-affected rootstock bark. This set of protein spots was identified as chitinases. Another set of proteins, ranging in pI from 6.1 to 9.6 with an MW of about 20 kDa, were also suppressed in CSD-affected rootstock bark; these were identified as miraculin-like proteins, potential trypsin inhibitors. Downregulation of chitinases and proteinase inhibitors in CSD-affected plants is relevant since chitinases are well-known pathogenesis-related protein, and their activity against plant pathogens is largely accepted.

Caracterização morfológica, citogenética e molecular de uma população de tangerineiras híbridas de 'Clementina fina' (Citrus clementina Hort. ex Tan.) e 'Montenegrina' (Citrus deliciosa Ten.)

A produção citrícola se encontra dispersa por todos os continentes e no Brasil, os citros são a produção frutícola de maior volume de produção. A produção de citros de mesa, como as tangerinas, possibilita ao produtor obter maior valor pelo seu produto. O mercado consumidor é ávido por novas variedades e para tanto, um programa de melhoramento deve estar sempre em busca de genótipos que atendam ao mercado consumidor, bem como a cadeia produtiva. Na Estação Experimental Agronômica da Universidade Federal do Rio Grande do Sul, está localizada uma população de tangerineiras híbridas oriundas do cruzamento da tangerineira ‘Clementina Fina’ (Citrus clementina Hort. ex Tan.) e ‘Montenegrina’ (Citrus deliciosa Ten.) a qual foi caracterizada neste estudo, avaliando-se características morfológicas de acordo com os descritores propostos pelo International Board for Plant Genetic Resources, além da identificação da época de maturação, viabilidade de pólen, número cromossômico e caracterização molecular, utilizando marcadores do tipo microssatélites. Através da análise morfológica foi possível distinguir todas as 96 plantas avaliadas, porém não foi possível agrupar a F1 em grupos distintos de cada um dos genitores. A época de maturação de frutos das plantas se concentra entre a primeira quinzena de abril até a primeira quinzena de agosto. Todas as plantas analisadas apresentaram um alto grau de viabilidade de pólen, variando entre 79,04 e 98,08 %. Todas as plantas avaliadas são diplóides com um número cromossômico de 2n=18. Utilizando 12 pares de primers de microssatélites foi possível diferenciar 90 acessos do estudo, e agrupar a F1 em indivíduos mais próximos do genitor feminino e do genitor masculino. O PIC (Conteúdo de Informação de Polimorfismo) dos primers variou de 0,27 a 0,65. Não foi possível estabelecer uma relação entre a caracterização utilizando marcadores morfológicos e a caracterização utilizando marcadores moleculares.

EFEITO do ÁCIDO GIBERÉLICO (AG3) NA FLORAÇÃO E PRODUÇÃO da LIMA ÁCIDA 'TAHITI' (Citrus latifolia Tan.)

A floração nos citros, assim como em outras fruteiras, é um dos fatores determinantes para a produção. A possibilidade de inibição ou redução da florada normal e alteração da época de produção para a lima 'Tahiti' é fator primordial para determinar sua rentabilidade econômica. O presente trabalho teve como objetivo avaliar o efeito do ácido giberélico sobre a florada, número de flores formadas, da lima ácida 'Tahiti', nas condições do Estado de São Paulo durante dois anos, buscando inibir a florada normal e observar o efeito desta inibição sobre produções temporãs. O delineamento experimental foi em blocos casualizados (5 blocos) com 3 plantas por tratamento. Foi utilizada uma planta como bordadura entre os tratamentos e uma linha de plantas entre os blocos. Os tratamentos foram: testemunha, 20, 40 e 80 mg/L de ácido giberélico (AG3) + 10 ml/L de espalhante adesivo, e o pH da água utilizada foi 6,2. As plantas foram tratadas com ácido giberélico durante o inverno (estação seca) após 50 dias sem irrigação no primeiro ano e 60 dias no segundo. O ácido giberélico reduziu o número de flores formadas (-81%) e aumentou a produção de frutos temporões (+59,77% ou +16,04 kg/pl).

Desbaste da limeira-ácida-'Tahiti' (Citrus latifolia Tanaka) com TPA e efeitos na produção

Foram avaliadas concentrações de 0; 10; 20; 40 e 80 mg/L do 3,5,6-TPA (Ácid 3,5,6-tricloro-2-piridil- oxiacético), em sua formulação éster, para desbaste de frutos novos da limeira-ácida-'Tahiti' (Citrus latifolia Tanaka), nas condições ecológicas do Estado de São Paulo. O 3,5,6-TPA, na concentração 10mg/L, foi o tratamento mais eficaz para uso na cultura. Concentrações maiores causaram severos danos às plantas. Essa concentração, aplicada logo após a florada de outubro, reduziu em 65% a produção do mês de fevereiro seguinte. Todavia, as produções dos meses subseqüentes não diferiram entre si. A concentração de 10mg/L causou alongamento dos frutos, aumento da espessura da casca e redução do Brix, na época da colheita.

Effect of citrus sudden death on yield and quality of sweet orange cultivars in Brazil

Citrus sudden death (CSD) has greatly affected sweet orange cultivars grafted on Rangpur lime in São Paulo and Minas Gerais States, Brazil. To characterize and quantify CSD damage, fruit yield and quality were assessed in each combination of sweet orange cultivar (Hamlin, Pera, Natal, and Valencia), age class (3 to 5, 6 to 10, and 11 to 15 years old), and CSD severity class (0 = no symptom, 1 = initial symptoms, and 2 = severe symptoms). For each combination, 10 trees were harvested and 20 fruit were taken for quality analysis. Damage was characterized by reduc_ tion of: (i) total weight of fruit/tree (36 and 67% for severity class 1 and 2, respectively), (ii) number of fruit/tree (27 and 55%), (iii) fruit size (13 and 25% in diameter and height [stem to styler distance]), (iv) fruit weight (32 and 56%), (v) total soluble solids (TSS)/fruit (18 and 42%), and increase of (vi) Brix (14 and 34%), (vii) acidity (16 and 41%), and (viii) TSS/90-1b. box (21 and 33%). There was no alteration on Brix/acidity ratio and percentage of juice on fruit of affected trees. Sweet orange cultivars did not differ in percentage of reduction or increase of all yield and quality variables, with the exception of Pera, which expressed increases of Brix and acidity. For more severe affected trees, the youngest plants showed a higher reduction in fruit number/tree, whereas plants 6 to 10 years old showed a higher increase in fruit acidity and TSS/box. However, no differences in percentage of reduction or increase for other variables were observed among different age classes. The damage to the above probably was associated with reduced water absorption capacity of CSD-affected trees.

Susceptibility of citrus species to Alternaria alternata, the causal agent of the Alternaria brown spot

Alternaria alternata, the causal agent of Alternaria brown spot (ABS), causes necrosis on leaves, twigs, and fruit, reducing the productivity and quality of fruits. Tangerines and their hybrids are highly susceptible to the disease. Species, hybrids, and cultivars of Citrus from the germplasm bank of the Estacao Experimental de Citricultura de Bebedouro, São Paulo, Brazil, were evaluated in 2004 and 2005 with respect to their resistance to A. alternata, both through natural infection and by inoculation. Detached leaves were also used to demonstrate susceptibility or resistance to the disease. Ten cultivars of Satsumas (Citrus unshiu), and 14 cultivars of Clementine mandarin (C. clementina) did not show any symptoms of the disease in their leaves, either through natural infection or when inoculated in the field. The Burguess SRA-412, Wallent SRA-438, Carvalhais, Ampefy SRA-459, Ananas SRA, and Macaque SRA-426 mandarin hybrids (C. reticulata) did not show symptoms of the disease under natural or artificial infection in the field. Some cultivars of C. deliciosa, C. tangerina, C. erythrosa, and C. temple showed symptoms of the disease, even though no previous record of their susceptibility to Alternaria brown spot had been previously reported. The hybrids Fairchild, Nova, Page, Fortune, and Sunburst were susceptible to the disease. However, Fremont mandarin (a crossing between C. clementina and C. reticulata), Encore (C. nobilis x C. deliciosa), and Fallglo (C. reticulata x C. paradisi) did not show symptoms in field, and few symptoms were verified in detached leaves. These materials are promising for the cultivation of tangerines, and will enable genetic improvement for the development of cultivars resistant to Alternaria brown spot. (c) 2007 Elsevier B.V. All rights reserved.

Biofertilizer for control of Guignardia citricarpa, the causal agent of citrus black spot

Biofertilizers generated from the anaerobic and aerobic digestion of cattle manure, known as Bio1 and Bio2, respectively, were studied with regard to their microbial composition and effect on the mycelial growth of Phyllosticta citricarpa, the causal agent of citrus black spot (CBS). Two field experiments were conducted to determine the biofertilizer's potential (Bio1) in controlling CBS (2001/2002 and 2002/2003 crops). It was observed that the greatest number of microorganisms was found in the aerobically produced biofertilizer. Bio2 did not inhibit the mycelial growth of P. citricarpa. Mycelial growth of P. citricarpa was inversely proportional to the Bio1 biofertilizer concentration. In the 2001/2002 cropping season, the Biol effect in controlling CBS was directly proportional to its concentration, at the rate of 0 (healthy fruit), with R-2 = 0.88. Biol had a significant effect in controlling CBS, at a concentration of 10%, during the 2001/2002 cropping season, with DI values of 0.246 and 0.229 for the. 10 and 20% doses, respectively, compared to DI of 0.329 for the control. A directly proportional effect of the biofertilizer concentration on the percentage of fruits with a rating of zero was. also observed in the 2002/2003 cropping season, with R-2 = 0.48. However, even at doses higher than in the preceding cropping season, the biofertilizer was less effective, possibly due to a higher occurrence of the disease. Copper oxychloride and combined applications of copper oxychloride and carbendazim plus mancozeb controlled the disease. The possibility of using the biofertilizer as a protective biofungicide to replace copper oxychloride, especially in organic agriculture, should be explored. (c) 2005 Elsevier Ltd. All rights reserved.

Postharvest harpin or Bacillus thuringiensis treatments suppress citrus black spot in 'Valencia' oranges

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Transmission of Citrus leprosis virus C by Brevipalpus phoenicis (Geijskes) to Alternative Host Plants Found in Citrus Orchards

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)