Blackberry Plants Research Articles

Characterization ofGnomoniopsis idaeicola, the Causal Agent of Canker and Wilting of Blackberry in Serbia

Blackberry cane diseases with the symptoms of necrosis, canker, and wilting are caused by several fungi worldwide. Surveys conducted from 2013 to 2016 in Serbia revealed the occurrence of Gnomoniopsis idaeicola, the causal agent of cane canker and wilting, which was found to be distributed in almost half of the surveyed orchards, in three blackberry cultivars, and with disease incidence of up to 80%. Wide distribution and high disease incidence suggest that G. idaeicola has been present in Serbia for some time. Out of 427 samples, a total of 65 G. idaeicola isolates were obtained (isolation rate of 34.19%). Reference isolates, originating from different localities, were conventionally and molecularly identified and characterized. G. idaeicola was detected in single and mixed infections with fungi from genera Paraconiothyrium, Colletotrichum, Diaporthe, Botryosphaeria, Botrytis, Septoria, Neofusicoccum, and Discostroma, and no diagnostically specific symptoms could be related directly to the G. idaeicola infection. In orchards solely infected with G. idaeicola, blackberry plant mortality was up to 40%, and yield loses were estimated at 50%. G. idaeicola isolates included in this study demonstrated intraspecies diversity in morphological, biological, pathogenic, and molecular features, which indicates that population in Serbia may be of different origin. This is the first record of a massive outbreak of G. idaeicola infection, illustrating its capability of harmful influence on blackberry production. This study represents the initial step in studying G. idaeicola as a new blackberry pathogen in Serbia, aiming at developing efficient control measures.

Growth and Fruit Chemical Characteristics of Blackberry (Rubus Fruticosus) Cultivated with Vermicompost, Glomus Mosseae and Phosphate Rock

The aim of this investigation was to determine the effect of vermicompost (V) and phosphate rock (PR) on blackberry (Rubus fruticosus L. agg.) plants inoculated with Glomus mosseae (Nicol. & Gerd.) Gerdemann & Trappe (AMF). Plant growth parameters, total phenol compounds and total flavonoids were evaluated on leaves. Anthocyanin contents, soluble solids (SS), pH, titratable acidity (TA) and SS/TA ratio was evaluated in blackberries fruits. Blackberry plants were obtained from cuttings from field plants, which were distributed in soil according to a randomized complete block design with three repetitions. Treatments were vermicompost (10░g plant−1), phosphate rock (1░g plant−1), Glomus mosseae (AMF), (1░g plant−1), PR + AMF, V + PR, V +AMF, V + PR+ AMF and control without any amended. Plant height and stem diameter were measured five months after treatments, while total phenols and total flavonoids in leaves were evaluated eight months later. Anthocyanins, SS, pH, and TA were determined in blackberry fruits ten months after. Plant height was not statistically affected (p≤0.05), although total phenol compounds were higher (21.1░mg g−1 dry plant) in the V+PR+AMF treatment, whereas the V + AMF treatment produced more dry plant total flavonoids (1.4░mg g−1), compared with control plants. Blackberries produced with the vermicompost treatment had more anthocyanins (9.54░mg g−1) than control plants. Soluble solids, pH and titratable acidity were not statistically (p≤0.05) affected by any treatment.

Characterisation of bioactive compounds in berries from plants grown under innovative photovoltaic greenhouses

BACKGROUND: Bioactive compounds, mainly polyphenols, present in berries, are thought to be responsible for the health benefits of these fruit. Therefore, it is worthwhile to define the optimal environmental conditions to maximise their polyphenol content. OBJECTIVE: With the aim to define the optimal conditions for berry cultivation in an innovative environment, red raspberry, wild strawberry and blackberry plants were grown in a traditional greenhouse in comparison with two photovoltaic greenhouses with different shading area. METHODS: Hydroalcoholic extracts of ripe berries were evaluated by HPLC analysis, for their anthocyanins, organic acids and sugar contents. Moreover, phenolic content (by the Folin-Ciocalteu assay) and antioxidant activity (by the Trolox equivalent antioxidant capacity-TEAC assay) were assayed on the same berry extracts. RESULTS: Total anthocyanins, phenols content and antioxidant capacity tended to increase in berries grown under shading. The sugars content was, mostly, not negatively influenced by the shading. Conversely, the organic acids content, in some instances, increased along with the shading percentage. CONCLUSIONS: It can be concluded that it is possible to combine the greenhouse production of high-quality berries (with a particular focus on polyphenols, bioactive compounds valuable for human health) with the production of renewable energy, in the context of sustainable agriculture.

Frost-resistance of the blackberry (Rubus subg. Eubatus Focke) cultivars in the Forest-Steppe zone of Ukraine

Purpose. To improve the blackberry assortment based on studying the economic and biological peculiarities of new cultivars and their adaptabivity under the soil and climatic conditions of the Western Forest-Steppe zone of Ukraine for the further variety research and use in breeding programs. Methods. Laboratory, field, analytical and statistical ones. Results. Investigations were carried out to determine the influence of variable temperatures on 25 blackberry cultivars and their frostresistance to artificially created low temperatures (25and -30 °C). The degree of shoot tissue damage of blackberry plants with low temperatures in the field was also analyzed. Conclusions. The analysis of the degree of damage of blackberry plant shoots showed that a shoot apex appeared to be the most susceptible to the influence of low temperatures and the middle part of the shoot was most resistant. On the basis of the results of the laboratory free­zing of the blackberry plant shoots, cultivars were defined to be the most resistant to the both -25 and -30 °C low temperatures (‘Sadove chudo’ and ‘Orkan’). ‘Ouachita’ and ‘Cacanska Bestrna’ cultivars were also resistant to the temperature -25 °C (their total damage score did not exceed 9.0%). It is risky to cultivate ‘Nasoloda’, ‘Black Diamond’, ‘Tornfree’, ‘Loch Tay’, ‘Triple Crown’ and ‘Black Butte Blackberry’ in the areas where the temperature can be lowering to -25 °C without taking additional agrotechnical measures to protect against damage with low temperatures. The most sensitive to the temperature of -30 °C was the ‘Black Butte Blackberry’, ‘Nasoloda’, ‘Black Diamond’, ‘Black Pearl’ and ‘Jumbo’ cultivars (damage of more than 50% shoots was noted). This temperature conditions were critical for ‘Chief Joseph’, ‘Reuben’, ‘Tornfree’, ‘Karaka Black’, ‘Black Magic’, ‘Loch Tay’ and ‘Triple Crown’. The ‘Kiowa’ cultivar was quite resistant to both temperatures. The dependence of the shoots damage degree on the scrub architectonics was determined. The cultivars with creeping shoots are more susceptible to the effect of low temperatures than those that are more upright.

Physiochemical Changes in Floricane and Primocane Blackberries Harvested from Primocane Genotypes

Fresh-market blackberries (Rubus subgenus Rubus Watson) have a growing global market, with continued release of cultivars to meet demand for consumer-quality fruit. The release of primocane-fruiting blackberry plants that produce crops on both floricanes and primocanes has expanded blackberry production. This study investigated the physiochemical attributes of fresh-market blackberries harvested from two cane types (floricane and primocane) from four primocane genotypes (APF-238, APF-268, ‘Prime-Ark® 45’, and ‘Prime-Ark® Traveler’) grown at the University of Arkansas Fruit Research Station, Clarksville in 2015 and 2016. Year-to-year differences were evident as blackberries harvested in 2016 were smaller (6 g) and less acidic (0.7% titratable acidity) than berries harvested in 2015 (8 g berries with 0.9% titratable acidity); however, soluble solids in each year were similar (≈10.2%). Differences in genotypes were also a factor. ‘Prime-Ark® Traveler’ (2015) and APF-268 (2016) had the highest berry firmness (7.8–8.3 N). In both years, APF-238 had the lowest firmness (5.7–6.0 N), highest isocitric acid (0.8–1.1 g/100 g), and highest total anthocyanins (239–353 mg/100 g). Floricane fruit harvested from ‘Prime-Ark® Traveler’ had the highest berry weights (8.3–10.4 g) in both years. Blackberries harvested from primocanes were wider (21.3–22.9 mm), had higher soluble solids (11.6% to 12.6%), and had lower titratable acidity (0.6%) when compared with floricane fruit in both years. Major year-to-year differences were found for several variables in this study, indicating that environmental effects can be substantial and growers should be aware of this influence on berries harvested from the different cane types. Evaluation of quality properties of floricane and primocane fruit of primocane plants in other locations would be valuable, particularly from areas where commercial blackberry production is established.

Incidence of Viruses in Two Large-Scale Plantings of Blackberry in South Carolina as Detected Through the Use of Sentinel Plants and RT-PCR

Some plants in two large-scale blackberry plantings established from virus-indexed planting material displayed symptoms typical of virus infection in the early days of the growing season immediately after planting. Groups of sentinel plants exposed within the plantings for 30-day periods over additional growing seasons, and subsequently screened for the presence of five viruses by reverse transcription PCR, detected Blackberry yellow vein-associated virus (BYVaV), Blackberry virus Y (BVY), Blackberry chlorotic ringspot virus (BCRV), Blackberry virus E (BVE), and Blackberry leaf mottle-associated virus (BLMaV). Because these viruses are thought to be transmitted through the actions of arthropods, and bearing in mind that the plantings had been established with virus-indexed material, it seems that the viruses must be moving into the new crops from adjacent native vegetation and once established moving freely within the crops. BYVaV has been reported from South Carolina previously. A recent publication reports the detection of BLMaV in samples originating from South Carolina and demonstrates transmission of the virus by mites. This is the first report of the detection of BCRV, BVY, and BVE within the state and provides support for the movement of the latter two viruses (BVY and BVE) within established plantings of blackberry as a result of vector activity.

Improved resilience and metabolic response of transplanted blackberry plugs using chitosan oligosaccharide elicitor treatment

Transplanting of micropropagated blackberry plugs in the field during late summer and early fall is a common nursery practice for commercial blackberry production. During this field transition, blackberry plants generally experience different stresses in addition to transplanting shock coupled with sudden exposure to low night temperatures in the fall. Improving the stress resilience of field-transplanted blackberry plants by recruiting plant endogenous protective metabolic responses has significant merit. Therefore, the aim of this study was to improve stress resilience of newly transplanted ‘Chester Thornless’ blackberry in the field during fall transition through stimulation of phenolic antioxidant and proline-linked metabolic responses by using bioprocessed chitosan oligosaccharide (COS) as an elicitor treatment. Fourteen-week-old blackberry plugs were transplanted in the field in late July and COS was sprayed weekly in the run-off for a 6-wk period after transplanting. Total soluble phenolic content, total antioxidant activity, total proline content, proline dehydrogenase, and succinate dehydrogenase enzyme activity of blackberry shoots were evaluated weekly during and 1 wk after COS application. Improvement in total soluble phenolic content and antioxidant activity based on 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) free radical scavenging assay was observed in field-transplanted blackberry at 6 and 7 wk with COS elicitation treatment.

In-row Vegetation-free Strip Width Effect on Established ‘Navaho’ Blackberry

AbstractA field study was conducted in 2014 and 2015 in an established 5-yr old commercial blackberry planting to determine the effect of vegetation-free strip width (VFSW) on ‘Navaho’ blackberry vegetative growth, yield and fruit quality parameters, identify the optimum VFSW for blackberry plantings in the southeastern USA, and provide practical groundcover management recommendations that can increase the productivity of blackberry plantings. In Fall 2013, tall fescue was seeded in-row and allowed to establish. In Spring 2014, VFSW treatments (0, 0.6, 0.9, 1.2, and 1.8 m) were established in a randomized complete block statistical design with four replications. Blackberry growth measurements included primocane and floricane number, cane diam, individual fruit weight and yield. Fruit quality measurements included, soluble solids concentration (SSC), titratable acidity (TA) and pH. Primocane number increased with increasing VFSW in both years. Floricane number increased with increasing VFSW in 2014. Primocane diam decreased with increasing VFSW in 2014 but had a quadratic response in 2015. Berry weight and cumulative yield increased with increasing VFSW in both years. The only berry quality component affected by VFSW was pH, which decreased as VFSW increased. Results indicate that widening the VFSW in blackberry from the current recommendation of 1.2 m to 1.8 m could provide growers a means to increase plant growth, berry weight, and cumulative yield blackberry of a planting.

First Report of Leaf Rust on California Blackberry (Rubus ursinus) Caused by Kuehneola uredinis in California

In 2017, several wild California blackberry plants (Rubus ursinus Cham. & Schldl.) were observed with symptoms of leaf rust and severe defoliation within Monterey County, CA (GPS coordinates N 36°35′33.025″ W 121°49′58.67″). Representative samples (n = 5) were collected and stored at 4°C. Symptoms appeared primarily on older leaf surfaces and leaf edges. The adaxial leaf surface had circular to angular spots surrounded by brown necrotic tissue, and the abaxial surface had bright yellow-orange rust pustules (uredinia). Uredinia were erumpent and were 100 to 400 µm in diameter. Urediniospores were broadly obovoid, pale yellow-orange in color, and measured 28 to 40 × 24 to 32 µm (average 33 × 27 µm, n = 25) with echinulate spore walls 1.0 to 1.5 µm thick. Based on morphology and host information, the pathogen was identified as Kuehneola uredinis (Link) Arth., and a sample was deposited in the U.S. National Fungus Collection (BPI 910348) (Arthur 1906). To confirm this identification, DNA was extracted from urediniospores of one representative sample, and two separate PCR reactions were performed. A 1,755-bp fragment spanning 5.8S-ITS2-28S gene region of rDNA was amplified with Rust2inv and LR6 primers (fragment 1), and a 2,684-bp fragment spanning the 18S gene region of rDNA was amplified with Rust18S-R and NS1 primers (fragment 2) (Aime 2006). PCR products were sequenced with primers LR3 and LR0R (28S gene region) and NS5, NS6, and NS4 (18S gene region), described in Aime (2006). Fragment 1 shared 99% identity with a K. uredinis isolate (HMUT100497) from China (GenBank accession KU059177). Fragment 2 shared 98% identity with a Phragmidium sp. isolate (MB) from the United States (GenBank accession EF014363). The sequence match to the Phragmidium sp. isolate (MB) was likely owing to the absence of the 18S sequence of K. uredinis in the GenBank database. Sequences were deposited for fragment 1 and fragment 2 (GenBank accessions MF158087 and MF158088, respectively). To confirm the Rubus spp., genomic DNA was extracted from leaf tissue, and PCR was performed using ITS1 and ITS4 primers found in White et al. (1990). The product was sequenced with the amplification primers and shared 100% identity with R. ursinus internal transcribed spacer 1 and 2 (GenBank accession AF055794). R. ursinus is known as a parent of the loganberry (Rubus × loganobaccus L.H. Bailey), which is commercially grown and cultivated. K. uredinis has been reported on R. ursinus in Australia, New Zealand, and South Africa, and within the United States in Washington (Shaw 1973). K. uredinis has been reported in California on Santa Catalina Island on R. vitifolius Cham & Schldl., which is often a synonym of R. ursinus, but throughout the literature these are often described as distinct species (Millspaugh and Nuttall 1923). To our knowledge K. uredinis has never been reported in mainland California on R. ursinus or R. vitifolius. This is of particular concern given that (i) urediniospores disperse long distances by wind and (ii) several Rubus spp. (e.g., blackberry, loganberry, and raspberry) are susceptible in California and are economically important crops within 20 km of this reported observation.

Fusarium oxysporum f. sp. mori, a New Forma Specialis Causing Fusarium Wilt of Blackberry.

Fusarium oxysporum has recently been identified as the cause of a wilt disease affecting blackberry in California and Mexico. Thirty-six isolates of F. oxysporum obtained from symptomatic blackberry plants in California and Mexico were comprised of nine distinct somatic compatibility groups (SCGs). Phylogenetic analysis of a concatenated data set, consisting of sequences of the translation elongation factor 1-α and β-tubulin genes and the intergenic spacer of the ribosomal DNA, identified nine three-locus sequence types, each of which corresponded to an SCG. Six SCGs were present only in California, two only in Mexico, and one in both California and Mexico. An isolate associated with the most common SCG in California was tested for pathogenicity on blueberry, raspberry, strawberry, and lettuce. All blueberry, raspberry, and lettuce plants that were inoculated remained healthy, but two of the five strawberry cultivars tested developed symptoms. The three strawberry cultivars that were resistant to the blackberry pathogen were also resistant to F. oxysporum f. sp. fragariae, the cause of Fusarium wilt of strawberry. We propose to designate strains of F. oxysporum that are pathogenic to blackberry as Fusarium oxysporum f. sp. mori forma specialis nov.

Influence of Blackberry Plants on the Aroma Profile of Vitis vinifera L. cv. Pinot Noir

V. vinifera cv. Pinot noir vines were grown in pots together with blackberry plants and the effect of this association on the grape aroma was assessed. Preliminary data showed that vines that cohabited with blackberry had a different aroma profile compared to vine grown alone. The association with blackberry increased the concentration of 30 out 74 free aroma compounds and of 24 out 95 bound ones. No aroma compound was identified exclusively in the treated grapes.

Efecto de dos abonos orgánicos en las cadenas tróficas del suelo cultivado con mora

Soil fertilization with organic fertilizers comprises a practice that improves the soil biological properties; however, the effect of these on the soil food web (SFW) has been scarcely studied. The aim of this study was to determine the effect of two commercial organic fertilizers on the structure of the SFW associated with roots of blackberry plants (Rubus adenotrichos). The research was conducted in two blackberry plantations located one in San Martín de León Cortés, and the other one in Buena Vista de Pérez Zeledón in San José, Costa Rica, from August to December, 2010. In the two plantations, plants were fertilized with compost or vermicompost. The roots of blackberry plants surrounding soil were sampled in order to quantify groups of the SFW through the following techniques: bacteria and filamentous fungi by plate count, protozoa by the most probable number, spores from arbuscular mycorrhizal fungi and nematodes by flotation-centrifugation, microarthropods, macroarthropods, and worms were directly counted in soil samples. The dataset was analyzed by multidimensional scaling analysis. The addition of organic fertilizers to soil caused a differential effect on the structure of the SFW (as compared with non-fertilized soils). The effect differed in soil from each of the experimental plantations according to fertilizer type. The groups of organisms mainly affected were actinomycetes and protozoa, which implies that the structure of SFW and consequently, the function of soil were not affected by the addition of organic fertilizers.

An assessment of the genetic integrity of micropropagated raspberry and blackberry plants

In vitro clonal propagation of small fruit species has been one of the most broadly exploited approaches in biotechnology. However, the most critical aspect of this propagation technology has been the maintenance of genetic fidelity of tissue culture-raised plants. In the present study, three techniques were deployed in the assessment of genetic fidelity of micropropagated plants (TC plants) of blackberry cultivar ‘Čačanska Bestrna’ and raspberry cultivar ‘Meeker’ in the second year after planting in the open field, in comparison to plants originating from the standard planting material (ST plants). Flow cytometry analysis deployed to estimate the DNA ploidy level and relative nuclear DNA content in TC and ST plants revealed no significant differences in nuclear DNA content between plants of different origin. Chromosome counting in root/shoot tip meristems also showed a normal tetraploid chromosome number (2n=4x=28) in TC blackberry plants and a normal diploid chromosome number (2n=2x=14) in TC raspberry plants. Polyacrylamide gel electrophoresis of peroxidase (POX) extracted from the leaf tissue revealed no differences in POX profiles between TC and ST plants either. The results obtained in this study verify the suitability of micropropagation by axillary branching for commercial exploitation in blackberry and raspberry.

Efecto de la salinidad sobre el crecimiento vegetativo de plantas de mora de Castilla (<i>Rubus glaucus</i> Benth.) micorrizadas y sin micorrizar

La mora en Colombia generalmente se siembra en suelos sin limitantes de salinidad, pero una fertilización basada en fuentes de síntesis química sin tener en cuenta sus requerimientos nutricionales o usar gallinaza sin compostar, podría ocasionar un efecto salino a largo plazo. En esta investigación se estimó el efecto de diferentes concentraciones de solución salina (0, 40, 80 y 120 mM NaCl) sobre el crecimiento vegetativo y absorción de nutrientes de plantas de mora de Castilla (Rubus glaucus Benth.) micorrizadas con Glomus proliferum Dalpé & Declerck cepa GB02 y sin micorrizar. Se estableció un diseño completamente al azar en arreglo factorial (4×2). Se evaluó crecimiento radical, acumulación de materia fresca y seca, concentración y absorción de nutrientes en hoja, tallo y raíz. Se encontró que la inoculación con micorrizas incrementó el crecimiento de las plantas bajo condiciones de estrés salino (40 y 80 mM), debido a un posible aumento de la adquisición de nutrientes minerales con una baja movilidad y a la toma reducida del Na. Con una concentración salina de 120 mM se disminuyó la absorción de Ca y se aumentó la de Na, lo que conllevó un menor consumo de agua. Igualmente, la planta disminuyó su capacidad para producir suficientes fotoasimilados que promovieran su desarrollo y el del hongo formador de micorriza, por lo que su crecimiento y producción de biomasa disminuyó notablemente. La asociación con el hongo permitió una mayor selectividad de la planta por el ión potasio, que por el sodio.

Molecular detection of Peronospora sparsa in sources of primary inoculum and components of resistance in wild blackberry species

Downy mildew caused by Peronospora sparsa is a major disease of blackberry (Rubus sp.) worldwide. The objectives of this research were a) to detect potential sources of primary inoculum of downy mildew of cultivated blackberry and b) to determine some components of resistance to P. sparsa in 4 wild blackberry species from Michoacan Mexico. A region-wide sampling of symptomatic and asymptomatic blackberry plants from nurseries, commercial plots, wild blackberries (R. adenotrichos) and rose plants (Rosa sp.), was conducted. Nested-PCR assays with PS3/PS1 primers in the first reaction followed by a second amplification with PR3/PR4 primers, amplifying a final fragment of 477 bp of the ITS region were used, and then sequenced in both directions. Detached leaflets of 4 common wild blackberry species were inoculated with P. sparsa sporangia under controlled conditions. Sporangiophores (SP) were recorded over a period of 18 days and oospores (OO) were counted 21 days after inoculation; the latent period (LP) and disease severity (DS) were also estimated. Phylogenetic reconstruction with Bayesian inference confirmed the presence of P. sparsa in all collected samples. Rubus adenotrichos, R. pringlei and R. sapidus were high inoculum producers, whereas R. cymosus allowed neither SP nor OO production and had the longest LP and lowest DS. Together, these results indicate that the primary source of inoculum for commercial plantings is mainly the blackberry plants from nurseries, and potentially 3 species of wild blackberries. Rubus cymosus has potential to be used in blackberry breeding programs as a source of resistance to P. sparsa.

Molecular diagnostic assays based on cpn60 UT sequences reveal the geographic distribution of subgroup 16SrXIII-(A/I)I phytoplasma in Mexico

Geographically diverse samples from strawberry exhibiting symptoms of Strawberry Green Petal (SbGP), periwinkle plants with virescence, and blackberry, blueberry, and raspberry plants displaying yellowing and inedible fruits, were assayed for the presence of phytoplasma DNA. PCR targeting the 16S rRNA-encoding gene and chaperonin-60 (cpn60) showed that the plants were infected with phytoplasma subgroup16SrXIII-(A/I)I (SbGP/MPV). To examine the geographic distribution of this pathogen in Mexico, we designed an array of cpn60-targeted molecular diagnostic assays for SbGP/MPV phytoplasma. A fluorescent microsphere hybridization assay was designed that was capable of detecting SbGP/MPV phytoplasma in infected plant tissues, successfully differentiating it from other known phytoplasma cpn60 UT sequences, while identifying a double infection with SbGP/MPV and aster yellows (16SrI) phytoplasma. Two quantitative assays, quantitative real-time PCR (qRT-PCR) and droplet digital PCR (ddPCR), gave similar results in infected samples. Finally, a loop-mediated isothermal amplification (LAMP) assay provided rapid detection of SbGP/MPV phytoplasma DNA. Application of these assays revealed that SbGP/MPV phytoplasma is widely distributed in Central Mexico, with positive samples identified from eleven localities within three states separated by hundreds of kilometres. These results also provide tools for determining the presence and geographic distribution of this pathogen in plant and insect samples in other localities.

A new, widespread emaravirus discovered in blackberry

A new virus was identified in blackberry plants exhibiting leaf mottling, chlorotic ringspots and curved midribs, symptoms associated with blackberry yellow vein disease (BYVD). The genome of the new virus, provisionally named blackberry leaf mottle-associated virus (BLMaV), was characterized and phylogenetic analysis revealed its close relationship to recognized members of the genus Emaravirus. BLMaV was transmitted by a yet to be described eriophyid mite species, further reinforcing its placement in the genus. Detection protocols were developed and used to determine the presence of the virus in plants collected from several areas in the U.S.A. The incidence of BLMaV was greater than 40% in BYVD-affected material.

Sticky trap predation in the Neotropical resin bug Heniartes stali (Wygodzinsky) (Hemiptera: Reduviidae: Harpactorinae)

Certain species of assassin bugs have evolved the sticky trap strategy to capture prey using adhesive substances on their legs. The resin bug Heniartes stali collects a sticky exudate from the trichomes of a blackberry plant and smears its legs with it through an intriguing gathering process. We report laboratory experiments aimed at understanding the capture behavior of H. stali when it encountered three insect prey species with different mobility: the coleopteran larvae of Tribolium castaneum, a slow-moving organism; workers of the aggressive and highly mobile ant Camponotus rufipes; and winged prey, the fly Drosophila sp. Bugs stalked prey approaching within reach of their forelegs. After the bug threw forwards its forelegs, the prey became stuck and was subsequently held firmly by clutching with the aid of the middle legs, also smeared with trichome exudate. The bugs took longer to catch ants and immobilize them than larvae. Attacks on flies were unsuccessful because of flight escape before contact with H. stali occurred. A clear association between exudate harvesting and prey-capture behavior was unequivocally demonstrated. This is the first detailed description of a sticky leg trap from harvested plant exudate in Heniartes and related prey-capture behavior.

In vitro propagation of Rubus macrocarpus Benth. and Rubus bogotensis Kunth, as an ex situ conservation strategy

This research aimed to evaluate techniques for in vitro multiplication and rooting and ex vitro adaptation of wild blackberry plants (Rubus bogotensis Benth. and Rubus macrocarpus Kunth). In in vitro phases, the influence of culture media was evaluated based on Murashige & Skoog (MS) composition, with or without a 50% reduction in salts, vitamins, and myo-inositol and supplemented or not with benzylaminopurine (BAP), indole acetic acid (IAA), L-cysteine, agar, peat, perlite, and vermiculite. The ex vitro phase was based on a soil, rice husks, peat, and perlite substrate management. After two months of evaluation of the in vitro phases, it was determined that the MS medium at 50% salts, vitamins, and myo-inositol and supplemented with sucrose (15000 mg.l-1) and agar (5000 mg.l-1) was the most suitable for obtaining the highest values of apical length (cm), shoot number, rooting percentage, and root number. In ex vitro adaptation, the acclimation subphase, evaluated during three months, allowed to determine survival rates of 83.33% and 75% for R. macrocarpus and R. bogotensis, respectively. The average increase in stem length (cm) was 2.35 cm and 1.30 cm, respectively. In the greenhouse subphase, evaluated for four months, 100% plant survivorship was obtained, and 2.75 cm and 5.31 cm increases in average stem length (cm) for R. macrocarpus and R. bogotensis, were determined.

In vitro establishment of blackberry (Rubus sp.) cultivar 'Xavante'

ABSTRACT: The objective of this study was to evaluate the in vitro establishment of 'Xavante' blackberry under different conditions of plant luminosity and concentrations of salts of MS medium. The maintenance of 'Xavante' blackberry plants in the absence of light, with the use of MS medium with salt concentrations of 75% and 100% reduce bacterial contamination and the percentage of explants oxidized and provide the highest percentage of surviving and established explants. The 50% salt dilution in MS medium is not recommended when plants are subjected to the absence of light due to the high percentage of oxidized explants and consequently lower survival and establishment.