Mandarin Varieties Research Articles

Reação de híbridos de citros à inoculação com Alternaria alternata

RESUMO A mancha marrom de alternária (MMA), causada por Alternaria alternata, que produz uma toxina específica ao hospedeiro (Host Specific Toxin – HST) é uma doença de grande importância nos pomares de tangerinas no mundo. A doença afeta tangerinas, alguns de seus híbridos interespecíficos e pomelos, sendo que no Brasil, as principais variedades plantadas, a tangerina Ponkan e o tangor Murcott, são altamente suscetíveis ao fungo, que também é saprofítico alternativo, se reproduz nos pomares, sendo seus esporos facilmente disseminados pelo vento. Para esse trabalho, foram selecionados híbridos de citros, obtidos por cruzamentos dirigidos, por apresentarem características agronômicas que os tornam potenciais novas variedades de laranjas e tangerinas, tanto para a citricultura industrial, quanto de mesa. Esses híbridos foram avaliados quanto à resposta à MMA por meio da inoculação com A. alternata in vitro e in vivo, uma etapa imprescindível para a liberação de novas variedades. Foram selecionados mais de trinta genótipos resistentes ou que apresentaram poucos sintomas da doença. A seleção de variedades resistentes à doença é de grande importância econômica, pois além de diminuir os custos de produção, aumentados sobremaneira com a utilização do controle químico, contribui para a diminuição de inóculo no campo.

English

The goals of the present study were to identify resistant mandarin varieties with potential for the fresh fruit market that could enable an extension of the harvesting season and to develop appropriate methods to maintain fruit quality for longer storage periods. Fremont mandarin fruits were harvested at optimum maturity and stored with and without wax coating under different storage conditions: ambient (21 ± 2°C and 60 ± 5% relative humidity (R.H.)) and under refrigeration (8 ± 2°C and 90 ± 5% R.H.). Fruit physicochemical characteristics and acceptability and purchase intention, which were assessed through sensory analysis, were evaluated weekly. Mass loss was higher for fruits stored at ambient temperature. The soluble solids concentrations of fruits stored under refrigeration remained similar to the values measured at harvest. Fruits stored under refrigeration exhibited slightly higher gloss and color than fruits stored at ambient temperature. Wax-coated fruits exhibited lower mass loss and higher gloss and color than uncoated fruits. Similar results were observed for the sensory analysis: wax-coated fruits stored under refrigeration were better rated by panelists until the final evaluation (day 35 after the beginning of storage). Purchase intention was higher for fruits stored under refrigeration than at ambient temperature. It is concluded that uncoated fruits stored at ambient temperature exhibit a tendency to lose quality, which confirms the need for refrigeration and wax coating for post-harvest preservation of fresh citrus fruits. However, the physicochemical and sensory qualities of Fremont mandarins stored under refrigeration for 30 to 35 days are accepted by consumers.   Key words: Citrus spp., preservation, refrigerated storage, sensory analysis, post-harvest.

Traits Driving Tolerance to Atmospheric Fluoride Pollution in Tree Crops

Increased emissions of fluoride into the atmosphere contribute to reducing the sustainability of agricultural systems worldwide. In order to improve the understanding of the factors behind such phenomenon, varieties of citrus (Citrus spp.), Valencia sweet-orange, Ponkan mandarin, and Lisbon lemon and coffee (Coffea spp.), Obata, Catuai, and Apoata, were treated with fluoride nebulization. The trees were exposed to nebulization for 60 min inside a chamber by using medium (0.04 mol L−1) and high (0.16 mol L−1) doses of fluoridic acid (HF) during three nonconsecutive days in a single week, for a total of 26 days of exposure during the experiment. Sixty days after beginning nebulization, we evaluated leaf gas exchange, (ultra)structural organization, tree growth, and fluoride and nutrient concentrations in plant tissue. Photosynthesis and leaf dry mass of citrus and coffee varieties were affected differently by fluoride toxicity, and based on the tolerance index (relative leaf dry mass of control versus leaf dry mass of trees treated with 0.16 mol L−1 HF), the order of sensitivity for the varieties of each species was as follows: for citrus, lemon > mandarin > sweet-orange; and for coffee, Apoata > Catuai > Obata. The ability of the trees to control fluoride absorption most likely explained this contrast in sensitivity among varieties because both photosynthesis and leaf growth were negatively correlated with leaf fluoride concentration. Although disorganization of the thylakoids, degeneration of vascular cells, and disruption of the middle lamella occurred in leaves of all varieties exposed to fluoride, the more severe damage was observed in those with greater sensitivity to the pollutant (i.e., lemon and Apoata coffee). Taken together, these results provided insights into the factors that explain poor performance of citrus and coffee trees under fluoride pollution and also revealed the traits driving the tolerance of these crops such a limiting condition, which included a combination of the following: (i) reduced fluoride absorption, (ii) increased photosynthesis, and (iii) improved maintenance of the ultrastructural organization of leaves.

Gradient phonemic contrast in Nanjing Mandarin

The variety of Mandarin Chinese spoken in Nanjing does not have a contrast between [n] and [l]. The standard variety of Mandarin which is now taught in schools in Nanjing does have the contrast. Prior research has shown that listeners' subjective impression of sound similarity is modulated by linguistic experience. When sounds are contrastive in a language they sound more different than when they are not contrastive. We conducted an experiment to test the subjective perceptual consequences of lack of [n]/[l] contrast in Nanjing, and of learning the standard variety of Mandarin in school. The stimuli were seven instances each of [tana] [tala] and [tara]. The listeners were 16 younger (< 45 yrs) and 16 older speakers of Nanjing Mandarin, and 35 speakers of American English. The listeners' task was to rate on a 5 point scale their subjective impression of the difference between the words (1 = similar, 5 = different). For American English listeners [l]/[r] pairs and [n]/[r] pairs were rated as different (3.8) while [n]/[l] pairs were heard as a little more similar than this (3.3). For older Nanjing Mandarin speakers [l]/[r] and [n]/[r] pairs were very different (4.8) and [n]/[l] pairs were very similar (1.5). Younger Nanjing Mandarin speakers also rated [l]/[r] and [n]/[r] pairs as very different (4.6), while the [n]/[l] pairs were not as similar (2.25) (standard errors < 0.1). Exposure to a non-native phonological contrast seems to have perceptually enhanced it gradiently.

Elucidating the biochemical factors governing off-flavor perception in mandarins

Mandarins tend to develop off-flavors during storage, and this is attributed to induction of ethanol fermentation metabolism and accumulation of ethanol and its by-products. In order to elucidate the biochemical factors contributing to off-flavor formation in mandarins, we conducted sensory and aroma-volatile analyses of 41 different mandarin varieties within the Israeli citrus breeding collection, at harvest and after 6 weeks of cold storage at 6°C followed by 5days at 20°C. Descriptive sensory analysis with the aid of a trained panel revealed great diversity among mandarin varieties, in perceived off-flavors; and gas chromatography (GC) analysis revealed only a low correlation (R=0.14) between ethanol levels and perception of off-flavors. Gas-chromatography mass-spectrometry (GC–MS) analysis of levels and compositions of total aroma volatiles during postharvest storage revealed general increases in levels of alcohols and ethyl esters, and consequent decreases in levels of monoterpenes, sesquiterpenes, and aldehydes. Detailed volatile analysis of diverse varieties with strong and weak off-flavors revealed that the aroma volatiles compositions and the ratios between chemical classes of volatiles have completely changed during storage in varieties with strong off-flavors, but were less altered in varieties with weak off-flavors. In addition, we observed a negative correlation (R=−0.58) between monoterpene levels and off-flavor perception, i.e., most varieties with weak off-flavors had relatively high terpene levels, which might mask the perception of off-flavors. Overall, it is suggested that perception of off-flavors in mandarins does not depend solely on accumulation of specific volatile compounds, such as ethanol, but rather evolves during storage because of general changes in juice aroma-volatiles profiles and compositions which create an atypical or spoiled flavor.

The Dōngběi varieties of Mandarin

The Dōngběi dialects comprise a Mandarin subgroup that is related to, but nevertheless clearly distinct from, the Běijīng dialect. The dialects are an exceedingly young variety formed by a huge wave of emigrants from northern Chinese provinces who moved into the theretofore sparsely populated Manchurian territory in the late 19th and early 20th centuries. The new immigrants were primarily from Shāndōng and Héběi and they came in numbers that overwhelmed the languages spoken by the previous inhabitants, comingling with each other, then developing into a new set of regional varieties of Mandarin. This paper first examines the history of the population in China’s northeast and its growth from the beginning of the Qīng dynasty in the mid 17th century to its peak in the 20th, paying particular attention to the origins of the large Chinese speaking migration into the region at the end of the dynasty. Following, our study looks at the phonology and lexicon of the new regional varieties — the northeastern Mandarin dialects, investigating their characteristics and classification to show that historical and geographic factors have resulted in discernable differences between the Dōngběi and Běijīng dialects, differences that are sufficient to warrant separate classification.

Breeding and Analysis of Two New Grapefruit-Like Varieties with Low Furanocoumarin Content

Furanocoumarins (FCs) are a group of related plant defense metabolites occurring in several plant families, including some species in the genus citrus, such as grapefruit and pummelo. FCs function as toxins against pathogens, insects and other plant pests and some are toxic to humans at high levels. Although the levels of FCs in grapefruits are non-toxic to humans, they inhibit the intestinal enzyme CYP3A, thus preventing degradation of medicines, such as statins, and causing dangerous overdose effects. This overdosing can cause devastating side effects, ranging from stomach bleeding to kidney problems, muscle aches and irregular heartbeats. In the present study, we utilize LC/MS to characterize the levels of FCs pathway intermediates and end products in twelve citrus cultivars, including mandarin (Citrus reticulata), orange [Citrus sinensis (L.) Osbeck], Pummelo [Citrus maxima (Burm.) Merr.], grapefruit (Citrus paradisi Macf.), and two newly selected grapefruit like varieties [(Citrus reticulate) X [Citrus maxima (Burm.) Merr]. The orange and mandarin varieties do not contain FCs or FCs precursor compounds suggesting that this biosynthetic pathway is absent or inactive in mandarins and oranges and therefore a good genetic source for null alleles to FCs biosynthesis. We report the selection and characterization of two new low FCs and seedless grapefruit-like varieties, “Aliza” and “Coocki”, developed by a cross between pummelo and mandarin. Fruits of these varieties resemble grapefruit and contain high levels of the flavanone naringin, typical of grapefruit, but contain only trace amounts of FCs (based on LCMS analysis). Based on the variability of FCs content and inheritance in citrus species, the results suggest that future development of new low-FCs grapefruit varieties is an achievable objective.

Effect of magnetic water on yield and fruit quality of some mandarin varieties.

Effect of magnetic water on yield and fruit quality of some mandarin varieties.

Physiological, biochemical and sensory characterization of the response to waxing and storage of two mandarin varieties differing in postharvest ethanol accumulation

A loss of flavor quality often occurs with some varieties of mandarins (Citrus reticulata Blanco) following waxing and storage. This is thought to be due to the synthesis of ethyl esters which is stimulated by an accumulation of ethanol in the fruit as a result of anaerobic metabolism. The goal of this study was to determine the importance of postharvest ethyl ester accumulation to mandarin flavor in two important commercial mandarin varieties that differ in ethanol accumulation patterns. This study also aimed to enhance knowledge regarding the importance of ethanol accumulation to ethyl ester synthesis and overall flavor. In order to do this, comparisons were made between ‘Pixie’ (P) and ‘Gold Nugget’ (GN), mandarins that were previously identified as accumulating high and low amounts of ethanol, respectively, after waxing. In three of four harvests (H) at two different locations, P accumulated much higher concentrations of ethanol than GN after waxing and storage for 3 weeks at 5°C and 1 week at 20°C. Sensory panel analysis indicated that off-flavor development during storage was more pronounced in P than GN as were declines in overall acceptability. Flavor in fruit from Ojai, California (H4) was less negatively impacted by storage than fruit from the San Joaquin Valley of California (H1, H2, H3), for both varieties. Consistent with prior research, alcohols, esters and aldehydes were greatly altered in amount as a result of waxing and storage, with ethanol and the ethyl esters being the most prominent compounds, although ethyl ester concentration did not consistently relate to the amount of ethanol present. In H1 P had higher ethanol following storage than GN and correspondingly higher ethyl esters, while in H2 and H3 GN had significantly higher ethyl ester concentrations than P but did not have higher ethanol. Fruit from H4 had similar volatile concentrations between the varieties but ethanol was higher in P than GN. Internal oxygen concentrations in Pixie after waxing were lower than those in GN and likely were largely responsible for the greater ethanol accumulation observed in P. Following storage P tended to have higher pyruvate concentration and alcohol dehydrogenase (ADH) activity, while differences in pyruvate decarboxylase (PDC) activity were not consistent across harvests. Although the impact of waxing and storage on flavor was more negative for P than GN, the cause of this could not be simply ascribed to the greater tendency of P than GN to produce ethanol that in turn led to greater ethyl ester accumulation.

Citrus Growth and Rhizosphere Properties

Fifteen citrus varieties (four varieties of limes/lemons, three varieties of mandarins, and eight varieties of sweet oranges) were tested in a row-to-row multireplicate field experiment on Typic Rhodustalf. Pre-bearing growth behavior of different citrus varieties showed a significant difference (P ≤ 0.05) with respect to canopy volume (1.221 m3 with Bearss lemon and 0.220 m3 with Cara Cara Navel) governed by changes in different rhizospheric properties (soil-available nutrients, soil microbial population, and soil microbial biomass nutrients). Response in canopy volume was more governed by soil microbial biomass nutrients [carbon (Cmic), nitrogen (Nmic), and phosphorus (Pmic)] followed soil microbial population and soil available nutrients in decreasing order. Indices developed through diagnosis and recommendation integrated system further helped in partitioning interrhizosphere nutrient deficiencies. These studies suggested that (i) biological properties of rhizosphere soils of limes and lemons were of much superior quality and (ii) rhizospheric biological properties are transformed according to plant species and variety.

Diversity among mandarin varieties and natural sub-groups in aroma volatiles compositions.

Mandarins constitute a large, diverse and important group within the Citrus family. Here, we analysed the aroma volatiles compositions of 13 mandarin varieties belonging to seven genetically different natural sub-groups that included common mandarin (C. reticulata Blanco), clementine (C. clementina Hort. ex. Tan), satsuma (C. unshiu Marcovitch), Mediterranean mandarin (C. deliciosa Tenore), King mandarin (C. nobilis Loureiro), and mandarin hybrids, such as tangor (C. reticulata × C. sinensis) and tangelo (C. reticulata × C. paradisi). We found that mandarin varieties among tangors ('Temple', 'Ortanique'), tangelos ('Orlando', 'Minneola') and King ('King') had more volatiles, at higher levels, and were richer in sesquiterpene and ester volatiles, than other varieties belonging to the sub-groups common mandarin ('Ora', 'Ponkan'), clementine ('Oroval', 'Caffin'), satsuma ('Okitsu', 'Owari') and Mediterranean mandarin ('Avana', 'Yusuf Efendi'). Hierarchical clustering and principal component analysis accurately differentiated between mandarin varieties and natural sub-groups according to their aroma-volatile profiles. Although we found wide differences in aroma-volatiles compositions among varieties belonging to different natural sub-groups, we detected only minor differences among varieties within any natural sub-group. These findings suggest that selecting appropriate parents would enable manipulation of aroma-volatile compositions in future mandarin breeding programmes.

Hormonal Profile in Ovaries of Mandarin Varieties with Differing Reproductive Behaviour

The endogenous levels of 13 gibberellins (GAs), three cytokinins (CKs), abscisic acid (ABA), indole-3-acetic acid (IAA) and jasmonic acid (JA) were analyzed in naturally pollinated ovaries of three mandarin cultivars selected for their different capacity to produce seeds and their differing parthenocarpic ability. The varieties compared were Murcott (pollen self-compatible, highly seeded), Moncada (self-incompatible, moderately seeded), and Moncalina (pollen sterile, seedless), obtained from Moncada by bud γ-irradiation. As expected, the 13-hydroxylation pathway was predominant in ovaries and our results further indicate that cultivar differences exist in GA metabolism. The active gibberellin GA1 levels in ovaries seems to be related with presence of fertilized ovules and, therefore, with the ability to produce the seeds of a variety. Sterility gamma irradiation arrested the biosynthesis of GA1 and its precursor GA19 in Moncalina ovaries if compared to Moncada. The productive efficiency of the studied cultivars also indicated that fruit set depends strongly on the GA1 level achieved by ovaries, which is also closely related with carbohydrate content. The study of the expression of gibberellin-oxidase genes showed that the pollination/fecundation process enhances GA20ox2 and GA3ox1 activities in naturally pollinated Murcott and Moncada ovaries compared with unpollinated Murcott and Moncalina, respectively. GA2ox1 expression was lower in the ovaries of the highly seeded cultivar Murcott than in those of Moncada or Moncalina. Unpollinated Murcott ovaries contained much lower levels of GA1 and IAA than the naturally pollinated ovaries of this cultivar. Conversely, unpollinated ovaries, which exhibited 100 % abscission, had more ABA and JA contents. Cytokinin activity seemed constitutive and independent of pollination/fecundation. However, trans-zeatin (t-Z) and 2-isopentenyl adenine (2-IP) concentrations were higher in Murcott ovaries than in Moncada/Moncalina.

Diversity in sensory quality and determining factors influencing mandarin flavor liking.

We evaluated the sensory quality of 42 mandarin varieties that belong to 7 different natural subgroups: common mandarin (Citrus reticulata Blanco), Clementine (Citrus clementina Hort. ex. Tan), Satsuma (Citrus unshiu Marcovitch), Mediterranean mandarin (Citrus deliciosa Tenore), King mandarin (Citrus nobilis Loureiro), and mandarin hybrids, such as tangor (Citrus reticulata × Citrus sinensis) and tangelo (Citrus reticulata × Citrus paradisi). Consumer flavor acceptance tests revealed wide diversity in flavor preferences among mandarin varieties and subgroups. Furthermore, descriptive flavor-analysis tests conducted with the aid of a trained sensory panel revealed that the 9 most preferred varieties had similar flavor profiles, characterized by high sweetness, moderate to low acidity levels, low bitterness and gumminess, strong fruity and mandarin flavor, and high juiciness. The average total soluble solids (TSS) and acidity levels among the highly preferred varieties were 13.1% and 1.1%, respectively. In contrast, the 8 least preferred varieties were either too sour or gummy or had low levels of sweetness, fruity, or mandarin flavor, and either high acidity levels (>1.4%) or low TSS levels (<12.0%). Pearson tests revealed significant positive correlations between flavor acceptance and perceptions of sweetness, fruitiness, and mandarin flavor, and negative correlations with acidity levels and perceptions of sourness, bitterness, and gumminess. Principle component analysis clearly distinguished between highly accepted varieties that were tightly correlated with high TSS levels and perceptions of sweetness fruitiness and mandarin flavor, as compared with the least accepted varieties that were correlated with high acidity levels and perceptions of sourness, bitterness, and gumminess.

DATA MINING AND SYSTEMS BIOLOGY FOR IDENTIFYING KEY GENES INVOLVED IN CITRUS QUALITY

Quality in citrus is mainly characterized by fruit and juice colour, fruit and skin size, juice percent, total soluble solids, titrable acidity, and carotenoid/flavonoid contents. Moreover, studies of biosynthetic pathway of the metabolites/proteins involved in quality at transcriptional and translational levels may give relevant information for subsequent functional studies and quality improvement. Data mining of ESTs from HarvEST database allowed the selection of 17 cDNA libraries from albedo, flavedo, peel, pulp and juice sac of different orange, mandarin, clementine and grapefruit varieties. In order to select key genes involved in quality we used systems biology that offers mathematical tools that include the analysis of the structure, clustering and centralities of the network. In order to have information regarding physical protein-protein interactions (PPPI) from citrus sequences, orthologous sequences of Arabidopsis thaliana were used (BLASTX; reciprocal BLASTP). Literature data mining was performed, and PPPI network design was obtained using the Cytoscape software. The interactome networks thus obtained were analyzed with MCODE. Gene ontology clustering analysis was performed using BiNGO. Specific algorithms were applied to identify modules and central nodes within the citrus libraries associated network. The obtained results will be used as a guideline to select specific genes/proteins from citrus for further functional studies as gene expression or plant transformation. (Resume)

An acoustic comparison of dental and retroflex sibilants in Chinese Mandarin and Taiwan Mandarin

Mandarin has both dental and retroflex sibilants. While the Mandarin varieties spoken in China and Taiwan are often considered the same, native speakers of Mandarin can tell the difference between the two. One obvious difference is that between the retroflex ([ʂ], [tʂ], [tʂh]) and dental sibilants ([s], [ts], [tsh]). This study investigates the acoustic properties of the sibilants of Chinese Mandarin and Taiwan Mandarin. Eight native speakers each of Chinese and Taiwan Mandarin produced the six target sibilants in word-initial position. A number of acoustic parameters, including spectral moments and duration, were analyzed to address two research questions: (a) which parameters distinguish the dental and retroflex in each type of Mandarin; (b) is there a difference between Chinese and Taiwan Mandarin? Results show that retroflex sibilants have a lower M1 and M2, and a higher M3 than dental sibilants in each language. Moreover, Chinese Mandarin has significantly larger M1, M2, and M3 differences than Taiwan Mandarin. This pattern suggests that, in contrast to Chinese Mandarin, Taiwan Mandarin is merging the retroflex sibilants in a dental direction.

A Study on the Quality Criteria of Some Mandarin Varieties and Their Suitability for Juice Processing

In this study, some composition properties of juices of different mandarin varieties (Robinson (R), Fremont (F), and Satsuma (S)) were determined before and after pasteurisation. L*, a*, b*, and C* values of all varieties were increased after the pasteurisation process. Degradation of ascorbic acid was calculated as 2.20, 16.86, and 24.31% for R, F, and S samples, respectively, after pasteurisation. The highest total carotenoid and phenolic contents were determined in S samples. In general, after the pasteurisation treatment, the total carotenoid content of juices was increased slightly, but total phenolic contents were dramatically decreased. The antioxidant activity of pasteurised samples was increased by approximately 6%. The most abundant carotenoid and flavanone glycoside compound was shown to be β-cryptoxanthin and hesperidin, respectively, in all samples. The most popular fresh and pasteurised juice samples were made from the Robinson variety of mandarin with regard to taste, smell, and general impression.

Genetic diversity among mandarins in fruit-quality traits.

A detailed phenotypic analysis of fruit-quality traits was conducted among 46 mandarin varieties within the Israeli Citrus breeding collection, belonging to genetically different natural subgroups, including common mandarin (C. reticulata Blanco), clementine (C. clementina Hort. ex. Tan), satsuma (C. unshiu Marcovitch), Mediterranean mandarin (C. deliciosa Tenore), King mandarin (C. nobilis Loureiro), and mandarin hybrids, such as tangor (C. reticulata × C. sinensis) and tangelo (C. reticulata × C. paradisi). Evaluated qualities included physical attributes (size, shape, color, peel thickness, and seed number); physiological properties (ripening period, peelability, and segmentation); nutritional and biochemical composition (vitamin C, phenol, flavonoid, and carotenoid contents and total antioxidant activity); and sensory attributes (total soluble solids and acid levels, flavor preference, sweetness, sourness, and fruitiness). The results indicated wide genetic variability in fruit-quality traits among mandarin varieties and natural subgroups, and statistical and hierarchical clustering analysis revealed multiple correlations among attributes. Such phenomic analysis is an obligatory requirement for identification of molecular markers for distinct fruit-quality traits and for selection of appropriate parents for future breeding programs.

Híbridos de trifoliata como porta-enxertos para laranjeira Pêra

O limão Cravo (Citrus limonia) tem sido utilizado como o principal porta-enxerto para a laranjeira Pêra (C. sinensis). Entretanto, sua susceptibilidade ao declínio e à morte súbita induziu o uso de porta-enxertos tolerantes a doenças, como as tangerinas Cleópatra (C. reshni) e Sunki (C. sunki) e o citrumelo Swingle (C. paradisi x Poncirus trifoliata), mais susceptíveis à seca que o limão Cravo. As tangerinas são, também, menos resistentes à gomose de Phytophthora, e o citrumeleiro Swingle revelou ser incompatível com a laranjeira Pêra. Na busca por outros porta-enxertos, este estudo objetivou avaliar a precocidade e a produção de frutos, a susceptibilidade à tristeza e ao declínio e a ocorrência de incompatibilidade de laranjeiras Pêra enxertadas em 12 híbridos de trifoliata, no limão Cravo EEL e na laranja Goutou, sem irrigação. Tristeza e declínio são endêmicos na região. Os citrandarins Sunki x English (1628), Changsha x English Small (1710) e duas seleções de Cleópatra x Rubidoux proporcionaram as maiores produções acumuladas, nas três primeiras safras e no total de seis safras avaliadas. Os citrandarins Cleópatra x Rubidoux (1660) e Sunki x Benecke (1697) induziram precocidade de produção, enquanto o citromonia Cravo x Swingle e o citrange C-13 foram os mais tardios. Nenhum dos porta-enxertos causou alternância de produção. As laranjeiras Pêra enxertadas no citrumelo Swingle, citrandarin Cleópatra x Swingle (1654) e em duas seleções de limão Cravo x citrange Carrizo apresentaram sintomas de incompatibilidade, formando linha de goma na região de enxertia. Nenhuma das plantas apresentou sintomas de tristeza ou declínio.

Scientific Opinion on the risk of Phyllosticta citricarpa (Guignardia citricarpa) for the EU territory with identification and evaluation of risk reduction options

The Panel conducted a risk assessment of Phyllosticta citricarpa for the EU. P. citricarpa causes citrus black spot (CBS) and is absent from the EU. Under the scenario of absence of specific risk reduction options against P. citricarpa, the risk of entry of P. citricarpa was rated as likely for citrus plants for planting and citrus fruit with leaves, moderately likely for citrus fruit without leaves, unlikely for citrus leaves for cooking and very unlikely for Tahiti lime fruit without leaves. Establishment was rated as moderately likely because susceptible hosts are widely available and environmental conditions in many EU citrus-growing areas are suitable (with high uncertainty) for P. citricarpa ascospore production, dispersal and infection. Current fungicide treatments will not prevent establishment. Environmental favourability is increased by the use of sprinkler and micro-sprinkler irrigation in some EU citrus-growing locations. Spread with trade was rated as moderately likely. Model results indicate that CBS epidemics are most likely to develop in EU citrus-growing areas in late summer to early autumn and in some locations also in late spring to early summer. CBS is expected to affect mainly lemons and late-maturing sweet orange and mandarin varieties, with moderate negative consequences for the production of fresh fruit, but with environmental impact of additional fungicide treatments. Negative consequences would be minor for early-maturing citrus varieties and minimal for citrus for processing. Uncertainty concerning the consequences is high, mainly because of the lack of data on critical climate response parameters for the pathogen but also because information on impact in areas at the limits of the current distribution is scarce. Since eradication and containment are difficult, phytosanitary measures should focus on preventing entry. Current phytosanitary measures are evaluated to be effective, with the exception of pest-free production sites.

Biofilm Inhibition of Spoilage Bacteria by Argentinean Fruit Juices with Antihypertensive Activity

Argentinean juices have been studied for their antihypertensive activity, the inhibition of bacteria biofilm formation and the effect on the viability of wine yeast. The influence of phenolic compounds on these activities was evaluated. These studies are the first step for the development of a new type of wine that includes grape must supplement with fruit juices with antihypertensive effect. All juices posses a high antihypertensive activity, higher than 50%. Strawberry juices and eureka lemon showed the highest activity, whereas clarified juices posses the lowest activity. All studied juices produce a high inhibition of bacteria biofilm formation, and the strawberry, orange and mandarin varieties not affect the growth or viability of yeast. Our results permit to conclude that it could be possible the use of these juices in a new type of wine or as a source of new antihypertensive agents for pharmaceutical industry.