Characteristic Volatile Fingerprints and Odor Activity Values in Different Citrus-Tea by HS-GC-IMS and HS-SPME-GC-MS

Citrus tea is an emerging tea drink produced from tea and the pericarp of citrus, which consumers have increasingly favored due to its potential health effects and unique flavor. This study aimed to simultaneously combine the characteristic volatile fingerprints with the odor activity values (OAVs) of different citrus teas for the first time by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Results showed that the establishment of a citrus tea flavor fingerprint based on HS-GC-IMS data can provide an effective means for the rapid identification and traceability of different citrus varieties. Moreover, 68 volatile compounds (OAV > 1) were identified by HS-SPME-GC-MS, which reflected the contribution of aroma compounds to the characteristic flavor of samples. Amongst them, the contribution of linalool with sweet flower fragrance was the highest. Odorants such as decanal, β-lonone, β-ionone, β-myrcene and D-limonene also contributed significantly to all samples. According to principal component analysis, the samples from different citrus teas were significantly separated. Visualization analysis based on Pearson correlation coefficients suggested that the correlation between key compounds was clarified. A comprehensive evaluation of the aroma of citrus tea will guide citrus tea flavor quality control and mass production

Development and evaluation of a loop-mediated isothermal amplification (LAMP) assay for the detection of Tomato brown rugose fruit virus (ToBRFV).

Tomato brown rugose fruit virus (ToBRFV) is a member of Tobamovirus infecting tomato and pepper. Within North America, both the United States and Mexico consider ToBRFV to be a regulated pest. In Canada, the presence of ToBRFV has been reported, but an efficient diagnostic system has not yet been established. Here, we describe the development and assessment of a loop-mediated isothermal amplification (LAMP)-based assay to detect ToBRFV. The LAMP test was efficient and robust, and results could be obtained within 35 min with an available RNA sample. Amplification was possible when either water bath or oven were used to maintain the temperature at isothermal conditions (65°C), and results could be read by visual observation of colour change. Detection limit of the LAMP was eight target RNA molecules. Under the experimental conditions tested, LAMP was as sensitive as qPCR and 100 times more sensitive than the currently used RT-PCR. We recommend this sensitive, efficient LAMP protocol to be used for routine lab testing of ToBRFV

Morphological characterization of fungi associated with the ascochyta blight complex and pathogenic variability of Mycosphaerella pinodes on field pea crops in central Alberta

Field pea crops in central Alberta were surveyed for ascochyta blight from 2011 to 2012 and fungal isolates were recovered from foliar lesions on selected plants. Cultural and microscopic characterization of the 275 isolates obtained revealed that 272 were of Mycosphaerella pinodes and three were of Phoma medicaginis var. pinodella. Ascochyta pisi or Phoma koolunga were not identified. Isolates of M. pinodes were divided into two groups, GI and GII, based on visual assessment of culture characteristics. GI isolates (light to dark, mostly gray colony color; pycnidial distribution radial and concentric; conidia 10.5–14.5 × 4.2–6.2 μm most with one septum, occasionally two, constricted at the septum; spore mass light buff to flesh color) were predominant (83%), while GII isolates (dark to gray colony color; pycnidia abundant; conidia 8–16 × 3.5–6.2 μm most with 1 septum, constricted at the septum; spore mass light buff to flesh color) were less common (17%). The cultures of GII isolates were similar to recent descriptions of A. pisi, but they differed in spore color. In a host differential study, 13 pathotypes of M. pinodes were identified from 110 single-spore isolates. Pathotype I was predominant (88 isolates) and virulent on all nine differential genotypes. The other pathotypes (pathotypes II–XIII) were rare (1–6 isolates of each). Comparison of the present results with earlier studies suggests that pathotype I has been prevalent for many years, and that its aggressiveness on the host differentials has increased over time. Emphasis should be placed on breeding for resistance to M. pinodes in field pea cultivars intended for deployment in central Alberta

Influence of resistant cultivars and crop intervals on clubroot of canola

Clubroot, caused by Plasmodiophora brassicae, is an important constraint on canola (Brassica napus) production in Canada. Rotations of clubroot-resistant (CR) canola cultivars in various sequences, and planting intervals between canola with non-host crops and fallow periods, were evaluated to determine their effects on clubroot severity and P. brassicae resting spore populations under field and micro-plot conditions. Under micro-plot conditions, the rotation sequences including CR canola, continuous fallow and the non-host barley reduced gall weight by 63-100% and clubroot severity by 34-100% compared with continuous planting of susceptible canola. No visible clubroot symptoms developed following continuous fallow or the non-host crop. Under field conditions, clubroot severity was very high (78% ID) in the continuous susceptible canola sequence. Most of the CR canola rotation sequences significantly reduced clubroot severity by 12-23%, but continuous fallow, continuous barley, and alternating the CR canola cultivars ‘45H29’ or ‘73-47’ with ‘TC72429-10’ reduced clubroot severity t by 32-36%. A comparison of intervals between canola crops, four cropping sequences, (continuous susceptible canola, alternating canola with barley or pea, a 2-year non-host interval between canola crops, and a 3-year non-host interval between canola crops), was conducted over 5 years. A 2- or 3-year non-host interval improved plant height, plant biomass and seed yield, and reduced gall mass, P. brassicae propagules in the soil and clubroot severity. A significant yield increase of more than 3600% was observed in a 3-year non-host interval.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Effects of Fusarium avenaceum and Rhizoctonia solani on growth of soybean in saline soils

Soybean (Glycine max) acreage on the Canadian prairies has increased rapidly in recent years. Production has expanded into semiarid regions where irrigation and drainage problems often result in the accumulation of salts in the soil. Fusarium avenaceum and Rhizoctonia solani are the two dominant pathogens in the disease complex that cause root and seedling blight of soybean on the Canadian prairies. The effects of F. avenaceum or R. solani in combination with soil salinity on soybean root rot were evaluated under greenhouse and mini-plot conditions. As expected, inoculation with F. avenaceum or R. solani consistently reduced seedling emergence and increased root rot severity on soybean. At high soil EC values, adverse the effects of the two pathogens were even stronger than at low salinity values. Twenty soybean cultivars were evaluated for their reactions to inoculation with F. avenaceum or R. solani in a saline soil (21.1 dS/m). High seedling emergence was observed in cultivars 900Y61, P002T04R, 900Y01, TH27005RR, P001T34R, and 900Y81 in the non-inoculated control, and for P002T04R and 900Y61 in the F. avenaceum treatment, and for 900Y61, 900Y81 and 900Y71 in the R. solani treatment. Root rot severity was low for cultivars NSC Portage and 900Y61 in the non-inoculated control and P002T004R in the F. avenaceum treatment. The cultivar 900Y61 also consistently had lower disease severity over the trials in the mini-plot test.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author