Streptomycin Rapid Test (Aquatic Products)

A self-powered aptasensor for streptomycin detection was constructed with a photofuel cell combined with a capacitor and a digital multimeter. The sensitivity of the proposed sensor was 8.7 times of that without using a capacitor amplifier circuit.

In 2019, fusarium head blight incidence and severity were assessed in 15 winter wheat fields in Manitoba. FHB occurred in 23% of the surveyed winter wheat fields. The provincial mean FHB severity (FHB Index) was 0.04%. INTRODUCTION AND METHODS: Winter wheat in Manitoba was surveyed for fusarium head blight (FHB) incidence and severity at 15 field locations. The survey was conducted in July when most of the fields were at growth stage ZGS 73-85 (Zadoks et al. 1974). In contrast to other disease surveys conducted in Manitoba, the fields were not surveyed at random. Instead, information on their location was obtained from producers. The proportion of infected spikes per field (incidence) and the proportion of infected spikelets in each spike (severity) were recorded for five heads (main stems) at 10 sites along a W pattern in the field, while avoiding sampling tillers. An FHB index (overall severity) was determined for each field surveyed: [Average % incidence X Average % severity]/100. Fifty spikes were processed from 15 fields for pathogen isolation and identification in the laboratory. Kernels from each field surveyed were surface-sterilized in a laminar flow bench and then placed on potato dextrose agar (PDA) (25% strength) + streptomycin media. Identification of Fusarium species involved microscopic examination and morphological characterization using the criteria of Leslie and Summerell (2006). RESULTS AND COMMENTS: According to Manitoba Agricultural Services Corporation's Variety Market Share Report (MASC 2019), there were approximately 32,846 acres of commercial winter wheat seeded in Manitoba for 2019. The top cultivars, based on their seed acreage, were 'Emerson' (53%) and 'AAC Gateway' (31.1%). FHB occurred in 23% of the surveyed winter wheat fields in Manitoba (Table 1). The provincial mean FHB severity (FHB Index) was 0.04%. FHB disease levels were lower in 2019 than the levels observed in 2018 (0.1%) (Henriquez et al. 2019). Overall, the 2019 provincial mean FHB index was the lowest FHB index recorded in the last five years (Derksen and de Rocquigny 2015; Henriquez et al. 2016, 2017, 2018, 2019) (Table 2). The results from kernels plated on PDA (25% strength) + streptomycin showed that Fusarium poae was the most frequently isolated pathogen species, accounting for 100% of isolations. This species was detected in 6.7% of surveyed fields. [GRAPHICS]