Transparent Plastic Boxes Research Articles

Characterization of Seed-to-Seedling Transmission of Alternaria brassicicola in Broccoli.

Alternaria brassicicola is part of a complex of Alternaria species that causes leaf blight and head rot in brassica crops such as broccoli, kale, cabbage, cauliflower, and collards. Seed can serve as a potential source of inoculum for the transmission of A. brassicicola in broccoli as demonstrated earlier; however, seed-to-seedling transmission of pathogen was never characterized empirically. So, the objectives of this study were to (i) re-evaluate the effect of artificial seed infestation on seed germination and seed-to-seedling transmission of A. brassicicola in broccoli; (ii) determine the effect of A. brassicicola-seed inoculum levels on seed-to-seedling transmission; (iii) evaluate if variations in A. brassicicola aggressiveness affect A. brassicicola seed-to-seedling transmission; and (iv) evaluate seed treatments that can reduce seed-to-seedling transmission of A. brassicicola in broccoli. Artificially infested seedlots were generated by inoculating broccoli seeds with a spore suspension of 1 × 105 conidia/ml of A. brassicicola using the vacuum infiltration method. Inoculated (n = 10 seedlots; 300 seeds/seedlot) or control seedlots in three replicates were planted on two layers of sterile blotter paper saturated with sterile water in transparent plastic boxes and incubated at 20°C and >90% relative humidity (RH) under continuous fluorescent light. Percent seed germination and percent seed-to-seedling transmission were recorded every other day for 21 days. Percent seed germination was significantly affected with artificial pathogen inoculation. One hundred percent of the seedlots transmitted the pathogen to broccoli seedlings, and seed-to-seedling percentages of the seedlots varied considerably. A strong linear and significant relationship between A. brassicicola inoculum level and seed-to-seedling transmission (%) within each seedlot was observed. Interestingly, variations in aggressiveness of A. brassicicola isolates did not affect seed-to-seedling transmission, as 100% of the seedlots were able to transmit the pathogen. Seed treatment with Miravis (a.i. pydiflumetofen 18.3%) significantly increased seed germination and reduced seed-to-seedling transmission percentages in A. brassicicola-inoculated seedlots. These results indicate that artificial seed inoculation with A. brassicicola can result in consistent seed-to-seedling transmission with significant impact on seed germination. Seed inoculum density of ≥104 conidia/ml is necessary for reliable transmission of A. brassicicola. Further seed-to-seedling transmission is not dependent on aggressiveness of A. brassicicola isolates and seed treatment with Miravis can significantly reduce pathogen transmission in broccoli seedings. Overall, this study provides detailed characterization of seed-to-seedling transmission of A. brassicicola in broccoli that can be further used to determine inoculum threshold, which has potential applications in seed-health testing and sample size determination. Furthermore, we also provide options for effective seed treatments that can significantly reduce A. brassicicola seed-to-seedling transmission and may potentially aid in managing seedborne fungal infection.

Prevention of the spread of infection during highly infectious autopsy using acraniotomy box.

In cranial autopsies, the post-mortem examination requires the use of a saw for the removal of the skull cap. In these procedures, sawing of bone becomes a critical source of infectious aerosols which spread instantaneously in the immediate environment, generating liquid aerosols including droplets of cerebrospinal fluid and blood, and leading to exposure of all autopsy personnel. In high-risk cases like prion disease, tuberculosis, severe acute respiratory syndrome (SARS), COVID-19, etc. where the skull would require sawing, the prime concern is the saw operator's exposure to these pathogens. Therefore, the author suggests the use of an ingenious ergonomic semi-circular craniotomy box during skull cap and brain removal in the autopsy procedure to successfully prevent the contamination of the entire autopsy hall. A transparent acrylic plastic box has been customized, which is semi-circular in shape having three walls, one semi-circular dome without a floor, a front wall with adjustable zipper closure, and a hind wall with circular holes with sleeves made of 5-layer fabrics. The dome contains one outlet for a vacuum suction pipe on the side, two holes on each side of the dome with non-woven fabric arms for the saw operator, and assistants' arms for performing skull opening procedures. The use of this box allowed the author to prevent and limit the spread of the generation of infectious aerosols in the autopsy hall as the bone dust collected in the vacuum ensures the safety of autopsy surgeons.

First Report of Leaf Spot on Panax notoginseng Caused by Caryophylloseptoria pseudolychnidis in Yunnan, China.

Panax notoginseng is a unique traditional medicinal plant in China, which has the effects of improving myocardial ischemia, protecting liver and preventing cardiovascular diseases (Jiang, 2020). In July 2021, gray-brown round spots were found on the leaves of P. notoginseng in the plantations of Lincang City (23º43´10˝N, 100º7´32˝E). By September, the symptoms were observed on more P. notoginseng plants, with incidence reaching 31%. Initial symptoms on leaves were small, brown spots that expanded, with black granular bulges on the lesions, often surrounded with yellow halo. As the disease progressed, multiple lesions merged, leaves became yellow, and abscission occurred. To isolate the causal pathogen, twelve symptomatic leaves were randomly obtained from twelve P. notoginseng plants. Small pieces of infected leaf tissues (about 5 mm2) were disinfected with 75% ethanol for 30 s, soaked in 2% sodium hypochlorite for 3 min, and then rinsed 3 times with sterile water and blotted dry. Sample tissues were plated on potato dextrose agar (PDA) plates incubated at 25℃ for 5 days with 12 h light/dark photoperiod. Hyphal-tips from the growing edge of colonies were transferred to fresh PDA to obtain pure cultures. Eight isolates were obtained with similar colony morphology, gray (top view) or black (back view) coloration, with a villous surface, and slow-growing on PDA. Conidia were hyaline, slender and obtuse to subobtuse at both ends, 10.3 to 52.62 (av. 25.2) µm × 1.4 to 4.0 (av. 2.4) µm (n=200) in size. Characteristics of the colonies and conidia were consistent with Caryophylloseptoria pseudolychnidis as described by Quaedvlieg et al. (2013) and Verkley et al. (2013). Genomic DNA of three representative isolates (LINC-4 to LINC-6) was extracted, and the rDNA-ITS region, ACT, and LSU gene regions were amplified and sequenced using the primer pairs ITS4/ITS5, 512F/783R, and LSU1Fd/LR5, respectively. Sequences have been deposited in GenBank (OK614104-OK614106 for ITS, OK614109-OK614111 for LSU, OK628350-OK628352 for ACT). BLAST search showed that all sequences were 98% to 100% homology with the corresponding sequences of C. pseudolychnidis. ITS sequences of the three isolates (LINC-4 to LINC-6) showed 99.21% identity (500/504 bp) to C. pseudolychnidis strain CBS 128630 (GenBank accession no. NR156266). LSU sequences of the three isolates showed 99.76% identity (823/825 bp) to C. pseudolychnidis strain CBS 128630 (MH876481). For ACT sequences, LINC-4 and LINC-5 showed 98.53% identity (201/204 bp) to C. pseudolychnidis strain 128614 (KF253599); LINC-6 showed 99.02% identity (202/204 bp) to C. pseudolychnidis strain 128614 (KF253599). Further, the neighbor-joining and maximum-likelihood method were used for multilocus phylogenetic analysis of the obtained sequences using MEGA-X (Kumar et al. 2018). The three isolates were clustered in the same clade with two C. pesudolychidis from database. Three isolates (LINC-4 to LINC-6) were tested for pathogenicity to confirm Koch's postulates. Annual potted P. notoginseng was inoculated with spore suspension (105 spores.mL-1). Each isolate was inoculated onto two leaves each of five P. notoginseng plants. The controls were similarly mock-inoculated with sterile water. To maintain high humidity (>90% RH), all plants were placed in transparent plastic boxes in a greenhouse at 25℃ with a 12 h light/dark photoperiod. Fifteen days post-inoculation, inoculated leaves showed similar symptoms to those observed in the field, and control plants remained healthy. The pathogen were reisolated from symptomatic leaf spots, and the colony characteristics were the same as those of the original isolates. Morphological characteristics, molecular data, and Koch's postulates tests confirmed C. pseudolychnidis as the cause of P. notoginseng leaf spot disease. To our knowledge, this is the first report of C. pseudolychnidis causing leaf spot on P. notoginseng in Yunnan, China. The spread of this disease might pose a serious threat to the production of P. notoginseng. The occurrence and spread of this pathogen should be further studied in order to formulate reasonable control measures.

First Report of a Leaf Spot Disease of Tobacco Caused by Pseudomonas cichorii in China.

Tobacco (Nicotiana tabacum L.), one of the chief commercial crops, is wildly cultivated worldwide. In June 2020 and 2021, an unknown bacterial leaf spot on tobacco was found in Hezhou and Hechi City, Guangxi, China. 30% of the tobacco were affected and the rate of diseased leaves reached about 10% in the field under high temperature and rainstorm. The disease mainly damaged the middle and top leaves of tobacco plants at vigorous growing stage. The initial symptoms were water-soaked spots on the frontal half of a leaf, and then expanded into circular to irregular spots with a yellow halo at the edge. The spots mostly appeared dark brown at high air humidity, while yellow brown at low humidity and exhibited a concentric pattern. In severe cases, the lesions coalesced and the whole leaf was densely covered with lesions, resulting in the loss of baking value. A bacterium was consistently isolated from diseased leaf tissues on nutrient agar (NA). Growth on NA was predominantly grayish white circular bacterial colonies with smooth margins, and the bacterium is rod-shaped, gram-negative and fluorescent on King's B medium. Seven isolates (ND04A-ND04C and ZSXF02-ZSXF05) were selected for molecular identification and pathogenicity tests. Genomic DNA of the bacterium was extracted and the housekeeping gene of cts (encoding citrate synthase) was amplified with the primers cts-Fs/cts-Rs (forward primer cts-Fs: 5'-CCCGTCGAGCTGCCAATWCTGA-3'; reverse primer cts-Rs: 5'-ATCTCGCACGGSGTRTTGAACATC-3') (Berge et al. 2014; Sarkar et al. 2004). 409-bp cts gene sequences were deposited in the GenBank database for seven isolates (accession no. OK105110-OK105116). Sequence of seven isolates shared 100% identity with several Pseudomonas cichorii strains within the GenBank database (accession no. KY940268 and KY940271), and the phylogenetic tree of cts genes of the seven isolates clustered with the phylogroup 11 of Pseudomonas syringae (accession no. KJ877799 and KJ878111), which was classified as P.cichorii. To satisfy Koch's postulates, a pathogenicity test was tested by using a needle to dip a suspension of the bacterium (108 CFU/ml) and pricking three holes in the tobacco leaf. The control plants leaves were needled with sterile water. Each tobacco plant was inoculated with three leaves, and the test was repeated three times. All plants were placed in transparent plastic boxes and incubated in a greenhouse at 25 ± 3°C. The water-soaked spots appeared 24h after inoculation and quickly expanded through leaf veins. Three days after inoculation, all the inoculated leaves showed symptoms similar to those observed in the field. Control plants remained healthy. Only P. cichorii was successfully re-isolated from the lesions, confirming Koch's postulates. Pseudomonas cichorii can infect eggplant, lettuce, tomatoand other crops, and has a wide range of hosts (Timilsina et al. 2017; Ullah et al. 2015). To our knowledge, this is the first report of P. cichorii causing leaf spot on tobacco in China.

Time reduction to evaluate Pinus taeda seeds germination by time-to-event analysis

The species Pinus taeda is largely used in intensive silviculture worldwide. This species has propagation through seeds, which requires determining seeds viability for their commercialization. The germination test recommended for this species usually requires up to 63 days to provide results on the quality of freshly harvested seeds, delaying commercialization and favoring contamination during the conduction of the test. The authors of this study aimed to establish the developmental stages of P. taeda seedlings to determine a criterion for interpreting the germination test with greater speed and efficiency to obtain results. The seeds were sown in transparent plastic boxes on two sheets of blotting paper and placed in a germinator at 22 °C with constant lighting. Five morphological stages of seedling development were defined with daily counts of the number of normal seedlings for each criterion, distribution in time, and the accumulated percentage of normal seedlings adjusted to time-to-event nonlinear regression. The new interpretation criterion proposed in this study is efficient, and P. taeda seedlings can be considered normal when cotyledon leaves differ by approximately 3 mm between the integument and hypocotyl, reducing the time to conduct the germination test by up to ten days compared to the criterion usually used in the routine analysis of seed laboratories.

Cold test on the vigor determination of Carthamus tinctorius L. seeds

In evaluating the quality of seed lots, vigor tests are complementary to the germination test, identifying differences in their degree of deterioration. However, for safflower seeds (Carthamus tinctorius L.) there is little information regarding these tests. Thus, the objective was to adapt the cold test methodology to evaluate the vigor of safflower seeds. For that, twelve lots were initially characterized by moisture content, mass of one thousand seeds, germination and seedling emergence in the field. After characterization the samples were conditioned in transparent plastic boxes on paper moistened with water and kept at 10 °C for the periods of 0, 3, 5 and 7 days. After the conditioning periods the samples were transferred to a germination chamber at 25 ºC, with evaluation of normal seedlings on the 3rd day. The obtained data was subjected to variation analysis and when significant, compared by the Scott-Knott method at 5% probability. To verify the efficiency of the methodologies, the principal component analysis was performed. The cold testing at 10 °C for 7 days is recommended for evaluating the physiological quality of safflower seeds.

Aerosols generation using Er,Cr:YSGG laser compared to rotary instruments in conservative dentistry: A preliminary study.

BackgroundIn restorative dentistry, the use of high-speed air turbine, which generates aerosols, can be associated with the transmission of airborne diseases. New laser technologies could be useful in reducing the amount of aerosols, but there is a lack of scientific research on this topic. Material and MethodsThis is a descriptive study to analyze the amount of aerosols produced after class I cavity preparation using high-speed air turbine (group 1) and Er,Cr:YSGG laser with two different parameters (groups 2 and 3). Fluorescein dye was incorporated into the coolant reservoir in order to visualize the production of aerosols during each procedure. Tooth preparation was performed in a typodont with human lower molar tooth under rubber dam isolation. The procedure was carried out in a transparent plastic box to avoid aerosols dispersion. Sixteen grade I cellulose filter discs were distributed along the surfaces of the box. The area contaminated with aerosols in the filters was measured using ultraviolet illumination. ResultsIn group 1, the contaminated surface area covered with fluorescein dye reached 77.3% (1349 cm2) of the total; in group 2 (laser with 80% water) we observed 7.3% (128 cm2) and in group 3 (laser with 40% water) it was 3.8% (68 cm2). The reduction in water parameter from 80% to 40% coincided with 48% reduction of the contaminated area on the filter discs. Focusing on the surfaces of the box, we noted that the mean contamination on the left side was more than on the right side in all three experimental groups. In group 1 using air turbine, we measured a mean of 102.6[±7.5 SD]cm2 on the left side, compared to 70.6[±32.3 SD]cm2 on the right side. In laser groups 2 and 3, a mean of 12.8[±14.9 SD]cm2 and 6.8 [±5.7SD]cm2, respectively, was described on the left surface versus 0 cm2 of surface contamination on the right surface. ConclusionsThe contaminated area during the procedure of class I cavity preparation, is reduced by 70% using Er,Cr:YSGG laser compared to high-speed turbine. A slightly higher contamination was observed between laser groups with 80% versus 40% water. The use of Er,Cr:YSGG laser in restorative dentistry can be a valid treatment alternative to reduce aerosols production compared to conventional high-speed rotary instruments. Key words:Er,Cr:YSGG laser, Aerosols, SARS-CoV-2, Rotary instruments, conservative dentistry.

Pre-germinative treatments and seed storage of Psidium cattleyanum Sabine morphotypes

This study aimed to evaluate the germination behavior of two morphotypes of P. cattleyanumsubmitted to storage and pre-germinative treatments. The experiment was designed in a factorial scheme 2 x 3 x 3 (morphotypes x storage periods x pre-germinative treatments) completely randomized, using for each treatment 5 replicates with 30 seeds. The seeds were stored in semipermeable packages in a cold chamber at 5 ± 2 °C, for 14, 45,and 90 days. After each storage period, the seeds were submitted to treatments to overcome dormancy: immersion in water at 80 °C,kept in imbibition for 24 and 48 hand control, without any treatment. The seeds were arranged under moistened substrate in transparent plastic boxes and allocated in a germination chamber at 25 °C and photoperiod of 8 h for evaluation of germination percentage (G), germination speed index (GSI)and mean germination time (MGT). The red morphotype seeds showed higher germination percentages than the yellow morphotype and did not have a reduction in these values after 90 days of storage. MGT for yellow morphotype was lower in all pre-germinativetreatments. The GSI had better results at 45 days in the control treatments and 24 h in immersion in water and 90 days for the three pre-germinative treatments. The red morphotype does not require pre-germinative treatments, while the yellow morphotype presents better germination when the seeds are stored for 45 days and immersed in water at 80 °C for 48 h.

The craniotomy box: an innovative method of containing hazardous aerosols generated during skull saw use in autopsy on a COVID-19 body.

During a disease pandemic, there is still a requirement to perform postmortem examinations within the context of legal considerations. The management of the dead from COVID-19 should not impede the medicolegal investigation of the death where required by the authorities and legislation but additional health and safety precautions should be adopted for the necessary postmortem procedures. The authors have therefore used the craniotomy box in an innovative way to enable a safe alternative for skull and brain removal procedures on suspected or confirmed COVID-19 bodies. The craniotomy box technique was tested on a confirmed COVID-19 positive body where a full postmortem examination was performed by a team of highly trained personnel in a negative pressure Biosafety Level 3 (BSL-3) autopsy suite in the National Institute of Forensic Medicine (IPFN) Malaysia. This craniotomy box is a custom-made transparent plastic box with five walls but without a floor. Two circular holes were made in one wall for the placement of arms in order to perform the skull opening procedure. A swab to detect the presence of the SARS-CoV-2 virus was taken from the interior surface of the craniotomy box after the procedure. The result from the test using real-time reverse transcriptase polymerase chain reaction (rRT-PCR) proved that an additional barrier provided respiratory protection by containing the aerosols generated from the skull opening procedure. This innovation ensures procedures performed inside this craniotomy box are safe for postmortem personnel performing high risk autopsies during pandemics.

First Report of Diaporthe passiflorae and Diaporthe nobilis Causing a Postharvest Kiwifruit Rot in Sichuan Province, China

In recent years, postharvest rot diseases of kiwifruit (Actinidia sp.) have caused severe damage in China (Li et al. 2017). Infected fruit were obtained from a commercial farm (30°98′N) after 4 months cold storage. Nineteen fruits (21.1%) out of one package showed rot symptoms with dark-brown, sour-smelling lesions. The lesions began as small pale yellow or light brown spots and then enlarged rapidly and formed dark or dark brown lesions. The margins between symptomatic and healthy tissues (4 × 4 mm) were cut from five rotted fruits, surface disinfested in 1% NaClO and 70% ethanol solution, washed, dried, plated on potato dextrose agar (PDA) containing 50 mg/liter of streptomycin sulfate, and incubated at 25°C for 3 days. Hyphal tips were transferred to PDA to obtain pure cultures. After 7 days, a total of 20 fungal isolates were obtained, including 16 previously reported Botrytis spp. (Xue et al. 2017), Penicillium spp. (Prodromou et al. 2018), and Alternaria spp. (Li et al. 2017), and four unknown isolates (DJY16A1-4, DJY16A1-5, DJY16A5-1, and DJY16A5-2). Strains DJY16A1-4 and DJY16A1-5 were incubated at 25°C for 7 days on PDA, wherein abundant white, fluffy aerial mycelium were grown on the dish. After 25 days, colonies produced black, spherical, or bluntly conical pycnidia. The conidia were hyaline, unicellular, ellipsoidal or fusiform in shape, and 6.52 × 3.43 µm in size. Similarly, incubated DJY16A5-1 and DJY16A5-2 formed white to light brown aerial mycelial mats with gray concentric rings. Pycnidia formed after 26 days, and α-conidia of the isolates were similar to those of the DJY16A1-4 and DJY16A1-5. β-Conidia were filiform or hamate, 23.9 × 1.2 µm in size. To identify these four isolates to species, the internal transcribed spacer (ITS), β-tubulin (BT), and translation elongation factor-1 alpha regions (TEF-1α) were amplified using specific primer pairs (You et al. 2015) and sequenced. By BLASTn analysis, DJY16A1-4 and DJY16A1-5 were 98% homologous to Diaporthe passiflorae CBS 132527 (NR_120155.1) based on ITS sequences (MH595928 or MH595929), 99 or 98% to D. passiflorae CBS 132527 (KY435674.1) based on BT sequences (MH621348 or MH621349), and 91% to D. passiflorae CBS 132527 (KY435633.1) based on the TEF-1α sequences (MH621352 or MH621353). DJY16A5-1 and DJY16A5-2 were 99% homologous to D. nobilis strain JL1 (KT163359.1) based on ITS sequences (MH595930 or MH595931), 97% to D. nobilis strain JL1(KX016113.1) based on BT sequences (MH621350 or MH621351), and 99% to D. nobilis strain 3JW-01S3 (KJ623308.1) based on TEF-1α sequences (MH621354 and MH621355). A phylogenetic tree was constructed using the method of maximum parsimony (MEGA7) with a combined dataset of ITS, BT, and TEF-1α sequences. Molecular phylogenetic analysis confirmed that DJY16A1-4 and DJY16A1-5 were D. passiflorae, and DJY16A5-1 and DJY16A5-2 were D. nobilis. The pathogenicity of the isolates was tested on the fruits of cultivars Xuxiang (A. deliciosa) and Zespri SunGold kiwifruit (A. chinensis). Ripe, healthy fruit were surface disinfected with 1% NaClO solution, rinsed in sterile distilled water, and dried. The middle of the fruit was stabbed with a sterile needle. Five wounded or unwounded fruits were inoculated with a 5-mm-diameter PDA plug with actively growing mycelium for individual isolates. Five wounded and five unwounded fruits were treated with sterile PDA plugs to serve as controls. Inoculated fruit were kept in sterilized transparent plastic boxes for 7 days at 25°C with 12-h light and 12-h dark. The wound-inoculated fruits produced the same symptoms as the rotted fruits collected initially from cold storage. Fruit rot was not observed on control fruit. The test was performed twice, and the fungi were reisolated and identified as either D. passiflorae or D. nobilis morphologically. D. lithocarpus was recently reported to cause kiwifruit rot (Li et al. 2016). But, to our knowledge, this is the first report of D. passiflorae and D. nobilis causing the postharvest rot in China.

Morphology and germination of Acmella oleracea L. R. Jansen under different temperatures and photoperiods

The objective was to evaluate the physical characteristics and physiological behavior of A. oleracea seeds during imbibition and germination, under different temperatures and photoperiods, as well as to determine the duration of the germination test. For this, biometric parameters (length, width and thickness) were measured in 100 seeds and thousand-seed weight was determined. In addition, the external structures of seeds and seedlings were described and the imbibition curve was monitored. Subsequently, the germination test was conducted at temperatures of 20, 25, 30, 35, 20-30 and 25-35 oC, under constant and alternating light and dark photoperiods (12 h), arranged in 6 x 3 factorial scheme, with four replicates of 50 seeds. Seeds were sown in transparent plastic boxes with blotting paper as substrate, germinated in Biochemical Oxygen Demand (B.O.D) incubator, and evaluated for six days. The following variables were analyzed: germination, germination speed index, seedling length and seedling dry mass. The imbibition pattern test was conducted at 25 oC with 4 replicates of 100 seeds, evaluated until 50% root protrusion occurred. A. oleracea seeds exhibit uniform physical characteristics and the three-phase model as a water absorption pattern. Constant temperatures of 25 and 30 °C and alternating temperatures of 20-30 °C, regardless of the photoperiod, led to higher germination values. For A. oleracea, the germination test evaluations can be performed on the fourth and sixth day after sowing, as first and last counts, respectively.

Intraspecific variation in litter palatability to macroarthropods in response to grazing and soil fertility

Abstract Clarifying the functional consequences of intraspecific trait variability in response to interacting trophic levels would provide a significant improvement in our understanding of above‐ground–below‐ground linkages. In particular, the effects of grazing on plant traits may translate into altered litter quality, with potentially important consequences for litter‐feeding decomposers. Plant and litter variability in response to grazing is expected to depend on soil fertility levels, with tolerance and defensive strategies more commonly expressed on fertile and poorer soils, respectively. However, how grazing and fertility interactively alter litter quality and palatability to detritivores has not been explored yet. We conducted a cafeteria experiment with three common millipede (Diplopoda) species feeding on leaf litter from two plant species, the grass Bromopsis erecta and the forb Potentilla verna. Each millipede was offered a binary choice between litter types produced by the same plant species, but sampled in plots with distinct herbivory and fertilization status: litter originating from grazed areas or from 1‐year sheep exclosures, both in native areas and in adjacent paddocks that received chemical N and P fertilization, as well as litter from a 25‐year sheep exclosures in the native area. We found that fertilization and herbivore exclusion interactively affected Bromopsis litter quality and palatability, whereas Potentilla was much less affected. Bromopsis litter palatability was not affected by grazing when litter was collected in native plots, except for the long‐term exclosure which led to low palatability. In contrast, and in line with our expectations, herbivory was associated with much higher palatability in fertilized plots. The changes in palatability were associated with important alterations of litter quality. Overall, our study demonstrates that intraspecific variation in litter can have profound consequences for soil functioning. It emphasizes the role of grazing as a key, but plant species‐specific factor controlling litter intraspecific variability, and its complex interaction with soil fertility level. Moreover, our results advocate for a better understanding of the response of the different organisms involved in the decomposition process, in particular litter‐feeding macro‐detritivores. We encourage future studies aiming at disentangling the various and complex relationships between above‐ground processes such as herbivory and soil functioning.

Germination, viability and longevity of horseweed (Conyza spp.) seeds as a function of temperature and evaluation periods

ABSTRACT: In Brazil, horseweed is one of the most important weeds because of the resistance to herbicides and high competitive for the crops. A large of losses were reported in major crops such as soybeans, wheat and corn, where the use a no-tillage system and the herbicide resistance promote better establishment. A correct understanding of the way temperature influences germination enables the prediction of the regions with the highest potential for colonization by this weed and thus facilitates its control. The objective of this study; therefore, was to discern the ways temperature affected the germination, viability and longevity of horseweed seeds. Testing was done at 10, 20 and 30°C, while evaluation occurred on days 0, 15, 30, 45 and 60. Seeds were packed in a nylon mesh bag (5x5cm), with 10g of upland soil (Yellow Red Argissolo, sandy loam texture), placed in transparent plastic boxes at 0 to 0.5cm soil depth, at the temperatures specified. Percentage of remaining seeds, first and second germination counts, abnormal seedlings, and dead, dormant, viable and non-viable seeds, were assessed. Horseweed seeds achieve secondary dormancy at 10, 20 and 30°C, while their quality and the longevity showed damage at 20 and 30°C temperatures.

BIOSTIMULANT EFFECT OF SEAWEED EXTRACTS APPLIED ON BEANS (Phaseolus vulgaris L.)

The present study evaluated the biostimulating effect on seed germination and initial vegetative development of Phaseolus vulgaris L. bean seedlings in response to the application of the aqueous extract of Osmundaria obtusiloba (C. Agardh) RE Norris (Rhodophyta) and Sargassum vulgare C. Agardh Ochrophyta), relating the activity with the contents of proteins and carbohydrates of extracts. Seaweed dried biomass of macroalgae were extracted at the concentration of 500 g L-1 in distilled water, this concentration was considered 100%. After was prepared in dilutions of 25%, 50%, and 0% (negative control) for each species. The experiment was conducted with 140 bean seeds in transparent plastic boxes kept in incubators under a12 hour photoperiod at the temperature of 25°C for 15 days. During this time, the germination percentage, germination speed and vigor of the seedlings (shoot length x radicle length) were assessed, as well as the sugar and total protein content of each seaweed extract. The results indicated that the development of seedling aerial biomass was 1.8 times higher with the extract at 25% concentration of O. obtusiloba than with the negative control. There were no changes in the germination parameters. Therefore, the O. obtusiloba extract showed a more positive effect on initial development than that of S. vulgare. The O. obtusiloba extract contained 160 mg L-1 while that of S. vulgare contained 80 mg L-1 total soluble proteins, indicating that protein content might be indicative of seaweed potential for application in agriculture.

Small-scale modelling of cementation by descending silica-bearing fluids: Explanation of the origin of arenitic caves in South American tepuis

Geoscientific research was performed on South American table mountains (tepuis) and in their sandstone cave systems. To explain speleogenesis in these poorly soluble rocks, two theories were introduced: a) arenization theory implying selective weathering of quartz along grain boundaries and releasing of sand grains, b) selective lithification theory implying cementation by descending silica-bearing fluid flow. The latter theory presumes that the descending fluid flow becomes unstable on the interface between two layers with different porosity and splits to separate flow channels (so-called “finger flow”). The arenites outside these channels remain uncemented.To verify the latter theory, small-scale modelling was performed, using layered sands and sodium-silicate solution. Fine to medium sand was used (0.08–0.5mm), along with a coarse sand fraction (0.5–1.5mm). The sands were layered and compacted in a transparent plastic boxes. Three liters of sodium-silicate solution (so-called water glass) were left to drip for several hours to the top of the sediment. The fine-grained layers were perfectly laterally impregnated, whereas the descending fluid flows split to “fingers” in the coarse-grained layers due their higher hydraulic conductivity. This small-scale laboratory simulation mimics the real diagenesis by descending silica-bearing fluids and matches the real phenomena observed on the tepuis. The resulting cemented constructions closely mimic many geomorphological features observed on tepuis and inside their caves, e.g. “finger-flow” pillars, overhangs, imperfectly formed (aborted) pillars in forms of hummocks hanging from ceilings, locally also thicker central pillars that originated by merging of smaller fluid-flow channels. The modelling showed that selective lithification theory can explain most of the geomorphological aspects related to the speleogenesis in tepuis.

First Report of a Bacterial Leaf Spot on Angelica dahurica Caused by Pseudomonas syringae in Gansu, China

HomePlant DiseaseVol. 101, No. 7First Report of a Bacterial Leaf Spot on Angelica dahurica Caused by Pseudomonas syringae in Gansu, China PreviousNext DISEASE NOTES OPENOpen Access licenseFirst Report of a Bacterial Leaf Spot on Angelica dahurica Caused by Pseudomonas syringae in Gansu, ChinaY. Wang, L. Jin, Y. E. Yao, C. Y. Zeng, and L. ZhangY. WangSearch for more papers by this author, L. JinSearch for more papers by this author, Y. E. YaoSearch for more papers by this author, C. Y. ZengSearch for more papers by this author, and L. ZhangSearch for more papers by this authorAffiliationsAuthors and Affiliations Y. Wang L. Jin Y. E. Yao C. Y. Zeng L. Zhang , Gansu University of Chinese Medicine, Lanzhou 730000; China. Published Online:27 Apr 2017https://doi.org/10.1094/PDIS-01-17-0078-PDNAboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Angelica dahurica (Umbelliferae) is a perennial medicinal plant abundant in China, Korea, and Japan (Lee et al. 2011). Its roots are used as traditional medicine in these countries to treat headache, bleeding, menstrual disorders, and neuralgia (Committee of China Pharmacopoeia 2005; Lee et al. 2011). During disease surveys in Gansu, China, on medicinal plants in 2011, a bacterial leaf spot disease was discovered with 32% incidence in cultivation fields in Longxi county. The disease incidence, severity, and area increased quickly in recent years. In 2016, the disease was found in Hezhen county with 70% incidence. The disease symptoms appeared on leaves initially as tiny, yellowish points, then became oil-soiled spots. When the disease was serious, oil-soiled spots densely scattered on leaves, veins became transparent, and the leaf crimped. Then the spot expanded to an irregular yellowish to brown lesion with a grayish inner part, brown oil streaks on leaf veins, and finally the leaves became dry and died. Symptoms were more apparent on new and tender leaves. Diseased leaves with oil-soaked lesions were picked and cut into 4 to 5 mm squares, surface sterilized in 1% sodium hypochlorite for 1 min, and then thoroughly washed three times in sterile distilled water. The tissues were crushed with a sterilized round head glass rod and diffused for 15 min, then loopfuls of the suspensions were streaked on nutrient agar (NA) medium and incubated for 48 h at 28°C. Causal bacterial colonies were circular, convex, milk-white, 0.8 to 1.2 mm in diameter, gram negative, and could induce hypersensitive response on tobacco leaves. The isolate (strain BZ2) can hydrolyze gelatin and starch, produce acid from glucose and mannitol, is positive to catalase, negative to Voges-Prokauer, esterase, and idole production, lack of phenylalanine deaminase, and is fluorescent on KBA. Pathogenicity tests were performed by artificial inoculation on A. dahurica potted plants. The bacterium (strain BZ2) was cultured on NA plate for 24 h, resuspended in sterile water, and adjusted to approximately 107 cfu ml–1. The bacterium suspension was inoculated into 10 leaves of A. dahurica by spraying and 10 leaves through injection method. Control plants were similarly treated with sterilized water. Inoculated plants were kept in a transparent plastic box to maintain >90% humidity at 23 ± 2°C in the lab and disease symptoms were evaluated daily. After 3 days, the typical irregular oil-soaked lesions appeared on the spray- and injection-inoculated leaves. Ten days later, the leaves wilted and the bacteria were reisolated from the diseased leaves, fulfilling Koch’s postulate. The total DNA was extracted from the isolate (strain BZ2) and 16S rRNA gene was amplified using the primer set (27f and 1492r) (Weisburg et al. 1991) and then submitted to GenBank (accession no. KY460679). BLASTn search yielded 100% identity with several strains of P. syringae, including PDD-59b-16 (KR922153), PDD-50b-9 (KR922075), PDD-51b-10 (KR922084), and CC1557 (CP007014). From the colony morphology, biochemical characteristics, and 16S rRNA sequence identity, the pathogen was identified as P. syringae. In 2002, bacterial speck caused by P. syringae on A. dahurica was reported in Jiangsu, Zhejiang, and Anhui provinces in China (Liu et al. 2002). This is the first report of the disease in Gansu Province. Future studies should place an emphasis on researching methods of control.

<b>Light regime and temperature on seed germination in <i>Salvia hispanica</i> L.

This study evaluated the effects of different light regimes and temperatures on the germination of S. hispanica seeds and used a factorial scheme in a completely randomized experimental design, in which three light conditions were combined with six temperatures (constant 20, 25, 30 and 35°C and alternating 20-30 and 25-30°C), totaling 18 treatments with four 50-seed replications. The seeds were sown on blotting paper in transparent plastic boxes and then allowed to germinate in Biochemical Oxygen Demand germinators. The seeds were evaluated over a period of eight days with respect to the following variables: germination percentage, average germination time, shoot and root lengths, shoot and root dry weights and root-shoot ratio. The data were submitted to Tukey's test (p ≤ 0.05%). The S. hispanica seed (beige colored) germination test can be carried out at constant (25°C) or alternating (25-30°C) temperatures. The germination of the seeds was indifferent to the light conditions evaluated; however, there was increased seedling growth and dry matter accumulation in the presence of light. The duration of the S. hispanica seed germination test can be five days, with the first count on the second day after sowing.

Low Cost Simulator for Heart Surgery Training.

ObjectiveIntroduce the low-cost and easy to purchase simulator without biological material so that any institution may promote extensive cardiovascular surgery training both in a hospital setting and at home without large budgets.MethodsA transparent plastic box is placed in a wooden frame, which is held by the edges using elastic bands, with the bottom turned upwards, where an oval opening is made, "simulating" a thoracotomy. For basic exercises in the aorta, the model presented by our service in the 2015 Brazilian Congress of Cardiovascular Surgery: a silicone ice tray, where one can train to make aortic purse-string suture, aortotomy, aortorrhaphy and proximal and distal anastomoses. Simulators for the training of valve replacement and valvoplasty, atrial septal defect repair and aortic diseases were added. These simulators are based on sewage pipes obtained in construction material stores and the silicone trays and ethyl vinyl acetate tissue were obtained in utility stores, all of them at a very low cost.ResultsThe models were manufactured using inert materials easily found in regular stores and do not present contamination risk. They may be used in any environment and maybe stored without any difficulties. This training enabled young surgeons to familiarize and train different surgical techniques, including procedures for aortic diseases. In a subjective assessment, these surgeons reported that the training period led to improved surgical techniques in the surgical field.ConclusionThe model described in this protocol is effective and low-cost when compared to existing simulators, enabling a large array of cardiovascular surgery training.

Some Biology Features of <i>Pempelia</i> spp. (Lepidoptera: Pyralidae): An Insect Pest of <i>Jatropha curcas</i>

Jatropha curcas L., a biofuel tree, is attacked by several insect pests, including Pempelia spp. (Lepidoptera: Pyralidae). This insect pest feeds on the stem and the leaves of the plant and can inflict severe damage to the shrub. This is why we studied its biology. Pempelia spp. larvae were collected in J. curcas’ plantations in the Leo, Bieha, Silly and Niabouri communes in the Sissili province of Burkina Faso, West Africa and were bred inside transparent plastic boxes. Immerged adults were separated into boxes after pairing them and were bred until their death. The female deposits its eggs in batches on the apical parts of J. curcas. Newly laid eggs are white pale. The first instar larvae are tiny and white pale or yellow. The 2nd instar larvae have a light green coloration, with longitudinal stripes. The 3rd instar larvae are lightly green with dorsal longitudinal stripes. The 4th instar larvae have a black head and a grey body. The 5th instar larvae have a blackish brown head with a dark reddish or light reddish longitudinal body. The mean duration of an instar is 8 days. The pre-pupa stadium is a period during which the larvae surround themselves with a white web developed from their saliva secretion. The pupa lives within a dark red cocoon. Pempelia spp. adults are grey. Female adults have large abdomen whereas males show a cylindrical and slender abdomen. These findings are the first of their kind reported in Burkina Faso. They are discussed in this paper.

English

Phytolacca dodecandra L’Heit (Endod var. E-44) is a medicinal plant of high saponin content used as a snail control agent in schitosomiasis. The aim of this study was to develop a micrpropagation protocol for P. dodecandra . Nodal and shoot tip explants were sterilized and cultured on MS medium supplemented with different types of concentrations and combinations of auxin and cytokinin for shoot induction, multiplication and root formation. Sodium hypochlorite at a concentration of 1.56% exposure of 12 min gave high percentages (81.67%) of survived explants for nodal followed by 1.3% concentration of NaOCl exposure of 10 min (73%) for shoot tip. 6-Benzylaminopurine (2.22 μM) was found to be an optimum concentration for shoot induction, yielding 80% for nodal and 70% for shoot tip explants. The combination of BAP (2.22 μM) with kinetin (2.33 μM) was obtained as optimum concentration yielding 13.4 and 11.03 shoots per explants for nodal and shoot tip, respectively for shoot multiplication. Half - strength MS medium with IBA (2.45 μM) and IAA (2.85 μM) yielded more than 90% root formation with optimum root number and length. Sterilized soil mix of 2:1:1 (top forest soil: coffee husk: sand) was optimized yielding 80% on transparent polyethylene plastic box. This developed micropopagation protocol is highly significant for large scale propagation of this species as a source of saponin extraction for drug development against endemic schitosomiasis. Key words: Explants, E-44 cultivar, plant growth regulators, micropropagation, detergents.