scholarly journals Influence of Citrus Source and Test Genotypes on Inoculations with Candidatus Liberibacter asiaticus

HortScience ◽  
2016 ◽  
Vol 51 (7) ◽  
pp. 805-809 ◽  
Author(s):  
Ed Stover ◽  
David G. Hall ◽  
Robert G. Shatters ◽  
Gloria A. Moore
Keyword(s):  
Rapid Screening ◽  
Host Genotype ◽  
Cross Sectional ◽  
Plant Materials ◽  
Detached Leaf Assay ◽  
Transmission Rates ◽  
Detached Leaf ◽  
Rough Lemon ◽  
Volkamer Lemon ◽  
Liberibacter Asiaticus

Assessments of the resistance of citrus germplasm to huanglongbing (HLB) can be expedited by inoculating plants under laboratory or greenhouse settings with the HLB bacterium, Candidatus Liberibacter asiaticus (CLas). Consistent rapid screening is critical to efficiently assess disease resistance among plant materials; however, a number of factors may govern the efficacy of such inoculations. Despite the rapidity at which HLB can spread in a grove, it often takes 8 to 10 months for high levels of CLas and HLB symptoms to develop even in highly susceptible sweet orange. Therefore, two experiments were conducted to assess factors that might influence efficiency in screening for HLB resistance. In one experiment, three test citrus genotypes (‘Kuharske’, previously shown to be HLB resistant; rough lemon, previously shown to be HLB tolerant; and ‘Valencia’, HLB susceptible) were bud grafted using CLas-infected buds from four different source genotypes. All bud source genotypes had similar levels of CLas titer, but citron, rough lemon, and Volkamer lemon were hypothesized to be better bud inoculum sources as they are more tolerant of HLB than ‘Valencia’. Among the three test genotypes over all sources of infected buds, inoculations of ‘Kuharske’ resulted in lower CLas titers and fewer HLB symptoms than inoculations of rough lemon or ‘Valencia’. Inoculations of rough lemon resulted in higher CLas titers and more pronounced HLB symptoms when it was inoculated using infected buds from rough lemon or ‘Valencia’. Grafting ‘Valencia’ with infected buds from Volkamer lemon resulted in less disease than when ‘Valencia’ was grafted with infected citron, rough lemon, or ‘Valencia’ buds. Overall, these results suggest that the source of CLas-infected buds used to graft-inoculate some genotypes will influence disease development. Trunk cross-sectional area increase for the year following infection was 3× higher in ‘Kuharske’ and rough lemon, compared with ‘Valencia’. ‘Kuharske’ had very low levels of CLas (30 CLas/µg DNA), whereas ‘Valencia’ (43,000 CLas/µg DNA) and rough lemon (6700 CLas/ µg DNA) had relatively high levels. As an alternative to graft-inoculating plants with CLas-infected buds, plants can be subjected to infestations of CLas-infected Asian citrus psyllid (ACP) as occurs naturally. Of interest is if transmission rates of CLas and the development of HLB in a genotype are greater when the ACP have been feeding on the same host genotype. An experiment was therefore conducted to assess transmission of CLas by ACP reared on CLas-infected rough lemon to five different genotypes (‘Carrizo’, ‘Flame’ grapefruit, rough lemon, ‘Temple’, and ‘Valencia’). These assessments were made using a detached leaf assay recognized as a faster method of gauging transmission rates of CLas than using whole plants. Higher percentages of ACP died when they were transferred from infected rough lemon to healthy ‘Carrizo’, and lower percentages died when they were transferred to rough lemon or ‘Flame’. However, CLas transmission by infected ACP occurred to at least some leaves of each genotype in each of the five different assays, with 70% or more leaves of each genotype becoming infected in at least one assay. Over all assays, there was relatively little variation among genotypes in the percentage of leaves becoming CLas infected and in the titer of CLas developing in infected leaves. However, there were relatively large differences in transmission rates among individual assays unrelated to differences among test genotypes. Because of the rapidity of the detached leaf assay, efforts are merited to improve consistency of this inoculation method.

scholarly journals Improved Detached Leaf Assay for Rapid Screening against Late Leaf Spot in Groundnut

2018 ◽  
Vol 7 (07) ◽  
pp. 3987-3993
Author(s):  
Dnyaneshwar B. Deshmukh ◽  
Ashwini M. Teggi ◽  
Hari Kishan Sudini ◽  
Sunil Chaudhari ◽  
Balram Marathi ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Rapid Screening ◽  
Detached Leaf Assay ◽  
Late Leaf Spot ◽  
Detached Leaf

scholarly journals First Report of Leaf Spot Caused by Corynespora cassiicola on Kiwifruit (Actinidia chinensis) in China

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1586-1586 ◽  
Author(s):  
G. Q. Yuan ◽  
Y. L. Xie ◽  
D. C. Tan ◽  
Q. Q. Li ◽  
W. Lin
Keyword(s):  
Leaf Spot ◽  
Morphological Characteristics ◽  
Its Region ◽  
Corynespora Cassiicola ◽  
Detached Leaf Assay ◽  
Detached Leaf ◽  
Concentric Pattern ◽  
Pathogenicity Tests ◽  
Petri Dishes ◽  
Whole Plants

Kiwifruit (Actinidia) is a common fruit cultivated in many countries. Actinidia deliciosa and A. chinensis are two commercially important kiwifruit species. Over 70,000 ha are grown annually in China. In 2012, a leaf spot disease of A. chinensis was observed in several orchards in Leye County (106°34′ E, 24°47′ N), Guangxi Zhuang Autonomous Region, China. The disease mainly damaged the leaves during the fruit development stage through to the maturity stage. Initially reddish-brown small lesions appeared on the leaves; later, typical symptoms were tan to taupe lesions surrounded by purple brown margins, nearly circular to irregular, 2 to 10 × 2.2 to 15.5 mm in diameter. Some lesions exhibited a concentric pattern. The lesions eventually coalesced, causing extensive leaf necrosis and defoliation. The fungus that sporulated from lesions had the following morphological characteristics: light brown conidiophores with slightly swollen apexes, light brown conidia formed singly or in acropetal chains, straight or curved, cylindrical to oblavate, 52.9 to 240.5 μm long (avg. 138.9 μm) and 5.3 to 13.6 μm wide (avg. 8.4 μm), 5 to 12 distoseptate, with a flat, darkened, and thickened hilum. These morphological characteristics corresponded with that of Corynespora cassiicola (Berk. & Curt.) Wei (1). To isolate the pathogen of the disease, small pieces of symptomatic foliar tissues, including young lesions, typical older lesions, and atypical older lesions with concentric pattern were surface sterilized with 75% ethanol for 30 to 60 s, disinfected in 0.1% HgCl2 for 1 min followed by washing with sterile water, plated on PDA, and incubated at 28°C for 7 to 10 days. Gray to dark gray colonies and conidia of C. cassiicola were observed. To validate the identity of the fungus, the sequence of the ITS region of one of the purified strains, LYCc-1, was determined. DNA was extracted from the isolate that was grown on PDA at 28°C for 4 days, and the ITS region was amplified using the universal primer pair ITS4/ITS5 (2). The double strand consensus sequence was submitted to GenBank (KJ747095) and had 99% nt identity with published sequences of C. cassiicola in GenBank (JN853778, FJ852574, and FJ852587). Pathogenicity tests were carried out on detached leaves in petri dishes in an incubator at 28°C and on whole plants in a glasshouse at 25 ± 3°C. The isolations did not produce enough conidia in pure culture, so mycelial discs were used in pathogenicity tests. For both assays, 60-day-old healthy kiwifruit leaves were inoculated with a 5-mm mycelial disc obtained from the periphery of a 5-day-old C. cassiicola strain (LYCc-1) grown on PDA. The PDA discs were placed on the leaf surface with their mycelial surface down and secured with sterile wet cotton. Controls consisted of leaves that were inoculated with sterile PDA discs. For the detached leaf assay, the leaves were placed on filter paper reaching water saturation in petri dishes, and for the whole plant assays the inoculated leaves were kept moist with intermittent water sprays for 48 h. Four leaves of each plant were inoculated with the isolate in both assays, and experiment was repeated twice. Eight inoculated leaves of the detached leaf assay all showed the first water soaked lesions 36 h after inoculation, followed by extensive leaf rot 72 h after inoculation, and yielded abundant conidia of C. cassiicola. Six out of eight leaves inoculated on whole plants showed the first lesions 5 days after inoculation, whereas control leaves remained healthy. Only C. cassiicola was re-isolated from the lesions in both assays, fulfilling Koch's postulates. This is the first report of leaf spot caused by C. cassiicola on kiwifruit in China. References: (1) M. B. Ellis. Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK, 1971. (2) T. J. White et al. In: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

Mapping seedling resistance to net form of net blotch (Pyrenophora teresf.teres) in barley using detached leaf assay

2014 ◽  
Vol 133 (3) ◽  
pp. 356-365 ◽  
Author(s):  
Janine König ◽  
Dragan Perovic ◽  
Doris Kopahnke ◽  
Frank Ordon
Keyword(s):  
Net Blotch ◽  
Seedling Resistance ◽  
Detached Leaf Assay ◽  
Detached Leaf

scholarly journals HSQC-NMR analysis of lignin in woody (Eucalyptus globulus and Picea abies) and non-woody (Agave sisalana) ball-milled plant materials at the gel state 10th EWLP, Stockholm, Sweden, August 25–28, 2008

Holzforschung ◽  
2009 ◽  
Vol 63 (6) ◽  
Author(s):  
Jorge Rencoret ◽  
Gisela Marques ◽  
Ana Gutiérrez ◽  
Lidia Nieto ◽  
J. Ignacio Santos ◽  
...  
Keyword(s):  
Picea Abies ◽  
Eucalyptus Globulus ◽  
2D Nmr ◽  
Structural Features ◽  
Rapid Screening ◽  
Nmr Analysis ◽  
Plant Materials ◽  
General Terms ◽  
Whole Plant ◽  
Agave Sisalana

Abstract In situ analysis of lignin by 2D NMR of whole plant material was carried out by swelling finely ball-milled samples in deuterated dimethylsulfoxide (DMSO-d6 ) and sonicated so that a gel was formed in the NMR analysis tube. Solution HSQC NMR spectra of different plant materials representative for hardwood (Eucalyptus globulus), softwood (Picea abies), and non-woody plants (Agave sisalana) are presented here. The spectra show signals corresponding to those of the main plant constituents, such as lignin and polysaccharides. The lignin signals were assigned by comparing the HSQC spectra of the whole plant materials with the HSQC spectra of their respective milled-wood lignins (MWLs). In general terms, the major lignin structural features, such as the relative abundances of the main lignin substructures, the syringyl/guaiacyl ratios and the extent of γ-acetylation of the lignin side-chain observed in the HSQC spectra of the whole plant materials, matched those obtained from the HSQC spectra of the isolated MWLs. Therefore, this technique, which needs only minor amounts of lignocellulosic material and minimal sample preparation, can be useful for the rapid screening of plant lignins without the need for tedious and time-consuming lignin isolation procedures.

scholarly journals Atopobium and Fusobacterium as novel candidates for sarcoidosis-associated microbiota

2017 ◽  
Vol 50 (6) ◽  
pp. 1600746 ◽  
Author(s):  
Alexandra Zimmermann ◽  
Henrik Knecht ◽  
Robert Häsler ◽  
Gernot Zissel ◽  
Karoline I. Gaede ◽  
...  
Keyword(s):  
Risk Allele ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Host Genotype ◽  
Microbial Composition ◽  
Cross Sectional ◽  
Associated Bacteria ◽  
Risk Variants ◽  
Generation Sequencing

Sarcoidosis is a granulomatous disease that mainly affects the lung. A role of microbial factors in disease pathogenesis is assumed, but has not been investigated systematically in a large cohort.This cross-sectional study compared the lung microbiota of 71 patients with sarcoidosis, 15 patients with idiopathic pulmonary fibrosis (non-infectious controls) and 10 healthy controls (HCs). Next-generation sequencing of 16S DNA was used on bronchoalveolar lavage samples to characterise the microbial composition, which was analysed for diversity and indicator species. Host genotypes for 13 known sarcoidosis risk variants were determined and correlated with microbial parameters.The microbial composition differed significantly between sarcoidosis and HC samples (redundancy analysis ANOVA, p=0.025) and between radiographic Scadding types. Atopobium spp. was detected in 68% of sarcoidosis samples, but not in HC samples. Fusobacterium spp. was significantly more abundant in sarcoidosis samples compared with those from HCs. Mycobacteria were found in two of 71 sarcoidosis samples. Host-genotype analysis revealed an association of the rs2076530 (BTNL2) risk allele with a decrease in bacterial burden (p=0.002).Our results indicate Scadding type-dependent microbiota in sarcoidosis BAL samples. Atopobium spp. and Fusobacterium spp. were identified as sarcoidosis-associated bacteria, which may enable new insights into the pathogenesis and treatment of the disease.

scholarly journals Rapid screening for behavioral risk factors in adolescents in North India

2019 ◽  
Vol 6 (8) ◽  
pp. 3343
Author(s):  
Poonam Banga ◽  
Tarundeep Singh ◽  
Rajesh Kumar
Keyword(s):  
Risk Factors ◽  
Drug Abuse ◽  
Alcohol Consumption ◽  
Fruits And Vegetables ◽  
North India ◽  
Rapid Screening ◽  
Behavioral Risk Factors ◽  
Behavioral Risk ◽  
Cross Sectional Survey ◽  
Cross Sectional

Background: Habits get established during the transitional age of adolescence making it important to conduct surveillance to detect high risk behaviours at an early age. Feasibility of such a surveillance system was tested for monitoring the risk factors in schools.Methods: A cross sectional survey was conducted in randomly selected schools of Chandigarh in India, by enrolling 226 students of class V to XII. A pretested structured questionnaire on dietary pattern, physical activity, tobacco and alcohol consumption, drug abuse, mental health, sexual behaviour etc., was administered after ensuring privacy and confidentiality.Results: A total of 226 students with a mean age of 14years (range 10 to 19years) participated in the study. The prevalence of tobacco use was 8%, alcohol consumption was 3%, and drug abuse was 4%. About 47% were involved in a physical fight. Around 7% students were overweight. About 50% of the students skipped breakfast during previous week, and 6% had no intake of fruits and vegetables in last one month. Only 53% reported consistent use of seat belts.Conclusions: Several behavioral risk factors were prevalent among school children in Chandigarh. Behaviour surveillance to monitor trends should be conducted at regular intervals.

The New FA₂ST Stroke Screening Score: An Expanding Recognition to Posterior Circulation Stroke

2021 ◽  
Vol 104 (7) ◽  
pp. 1132-1139
Keyword(s):  
Acute Stroke ◽  
Diagnostic Performance ◽  
Area Under The Curve ◽  
Posterior Circulation ◽  
Rapid Screening ◽  
Cross Sectional ◽  
Stroke Treatment ◽  
Posterior Circulation Stroke ◽  
Keywords Screening ◽  
Depth Analysis

Background: Rapid screening and intervention are the keys to successful early treatment of stroke. Generally, the conventional FAST stroke screening score has been used by triage nurses to promptly detect acute stroke. However, the conventional FAST score has a limitation in detecting posterior circulation stroke, which results in high mortality rates. Previous studies have shown that adding ataxia could increase the sensitivity of posterior circulation stroke detection. Objective: To introduce and evaluate the diagnostic performance of a new stroke screening score, FA₂ST score, by adding ataxia to the conventional FAST score. Materials and Methods: The present study was a cross-sectional study. The new FA₂ST and conventional FAST scores were used by triage nurses in patients presented with acute neurological symptoms within seven days at the emergency department of three different types of hospitals in Thailand. Patients with Glasgow Coma Score less than 9 and those having unstable vital signs were excluded. Final diagnosis was made by a neurologist using clinical and neuroimaging information. The diagnostic performance of the new FA₂ST score was calculated using ROC curve in comparison to the conventional FAST score. The rate of posterior circulation stroke detection was calculated as percentage. Results: One hundred forty-six patients were studied. Of these, 127 (86%) had acute ischemic stroke and 19 (14%) had other diagnoses. The overall diagnostic performance of the new FA₂ST score was not statistically different with conventional FAST score in terms of area under the curve (0.642 versus 0.684, p=0.221). However, after in-depth analysis, the rate of posterior circulation stroke detection of the new FA₂ST score was higher compared with the conventional FAST score (94.12% versus 82.35%). Conclusion: The present study introduces the new FA₂ST stroke screening score and emphasizes the importance of posterior circulation stroke detection in acute stroke screening. Future studies should be considered before implementation of this score. Keywords: Screening score; Acute stroke treatment; Stroke; Emergency neurology

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