First Report of Black Spot Caused by Penicillium citreosulfuratum on Saffron in Chongming Island

The Kentucky distilling industry ranks as one of the state’s largest industries and continues to expand. In 2017, the Kentucky distilling industry was responsible for approximately $235 million in state and local tax revenues (Coomes and Kornstein, 2019). Rye (Secale cereale L.) grains are a vital component for production of some distilled spirits.

1. Although winter rye is produced on relatively few hectares in Kentucky currently, a recent initiative has supported expanding production to help meet the growing demand of local distilleries.
2. University of Kentucky winter rye research field trials were visited in Caldwell and Logan Counties, KY in May 2018, and in Fayette County, KY in May 2019. Leaves were collected that had dark brown, oval to irregular-shaped lesions with definite margins and yellow halos. Symptoms were present on approximately 50% to 80% of the flag leaves, with severity ranging from 5% to 30% of the flag leaf area affected.
3. Leaves were surface-disinfested by soaking in a 2% NaOCl solution for 1 min and rinsed twice in sterilized water and then placed in a humidity chamber (plastic bag with moist paper towels) at room temperature (approximately 24°C) to induce fungal sporulation.
4. Seventeen single-spore isolates were obtained and stored at -80°C in 15% glycerol solution. Isolates were grown on potato dextrose agar under 12 h cycles of white light/darkness for 5 days. Colonies were gray to black. Conidia that formed were mostly straight or slightly curved, dark olivaceous brown, 3-7 septate, and 41.0-90.4 × 15.2-29.3 µm.
5. Based on the symptoms observed on the collected leaves and these morphological characteristics similar to those described by Chang and Hwang (2000) and Manamgoda et al. (2014), the fungus was tentatively identified as Bipolaris sorokiniana (Sorokin) Shoemaker. The sequence of internal transcribed spacer regions (ITS) and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) were used to identify three isolates (18Bs004, 18Bs111 and 19Bs064) using primer ITS1/ITS4 (White et al. 1990) and GPD1/GPD2 (Berbee et al. 1999), respectively.
6. The sequences were deposited in GenBank with accession numbers MT457817, MT457818 and MZ066635 for ITS sequences and MZ073644 to MZ073646 for GAPDH sequences. BLAST searches with ITS and GAPDH sequences matched 100% identity (344/344 bp and 515/515 bp for ITS and GAPDH sequences, respectively) to B. sorokiniana (GenBank accession No. MT254731 and MH844813, respectively).
7. To prove pathogenicity, a conidial suspension (1 × 105 conidia/ml) was used to inoculate 15-day-old cultivar ‘Serafino’ winter rye plants in the greenhouse. Leaves of 8 plants were inoculated with 50 ml of the conidial suspension using a spray bottle. Plants were covered with a transparent plastic bag for 48 h, and symptoms were observed 10 days after inoculation.
8. Leaf lesions, similar to those described above, were present on all inoculated plants, but no symptoms were observed on non-inoculated control plants. Bipolaris sorokiniana was reisolated from symptomatic leaves and the identity of the pathogen was confirmed based on the morphology previously described.
9. To our knowledge, this is the first report of spot blotch caused by B. sorokiniana on winter rye in Kentucky, but B. sorokiniana has been reported on rye in the neighboring state of Virginia (Roane 2009).
10. Kentucky produces approximately 150,000 and 4,000 ha of winter wheat (Triticum aestivum) and winter barley (Hordeum vulgare) annually, respectively, which are both known hosts of B. sorokiniana (Kumar et al. 2002).
11. An isolate of B. sorokiniana from rye was reported by Ghazvini and Tekauz (2007) to be less virulent on barley differential lines.

Further research is needed to better understand spot blotch distribution, susceptibility in winter rye cultivars, and potential yield and quality loss implications in winter rye production and end use. It is unknown how susceptible various winter rye cultivars grown in Kentucky are to spot blotch.

Nanoengineering of eco-friendly silver nanoparticles using five different plant extracts and development of cost-effective phenol nanosensor

The production of environmentally friendly silver nanoparticles (AgNPs) has aroused the interest of the scientific community due to their wide applications mainly in the field of environmental pollution detection and water quality monitoring. Here, for the first time, five plant leaf extracts were used for the synthesis of AgNPs such as Basil, Geranium, Eucalyptus, Melia, and Ruta by a simple and eco-friendly method.

• Stable AgNPs were obtained by adding a silver nitrate (AgNO₃) solution with the leaves extract as reducers, stabilizers and cappers. Only, within ten minutes of reaction, the yellow mixture changed to brown due to the reduction of Ag⁺ ions to Ag atoms. The optical, structural, and morphology characteristics of synthesized AgNPs were determined using a full technique like UV-visible spectroscopy, FTIR spectrum, XRD, EDX spectroscopy, and the SEM. Thus, Melia azedarach was found to exhibit smaller nanoparticles (AgNPs-M), which would be interesting for electrochemical application.
• So, a highly sensitive electrochemical sensor based on AgNPs-M modified GCE for phenol determination in water samples was developed, indicating that the AgNPs-M displayed good electrocatalytic activity. The developed sensor showed good sensing performances: a high sensitivity, a low LOD of 0.42 µM and good stability with a lifetime of about one month, as well as a good selectivity towards BPA and CC (with a deviation less than 10%) especially for nanoplastics analysis in the water contained in plastics bottles.

The obtained results are repeatable and reproducible with RSDs of 5.49% and 3.18% respectively. Besides, our developed sensor was successfully applied for the determination of phenol in tap and mineral water samples. The proposed new approach is highly recommended to develop a simple, cost effective, ecofriendly, and highly sensitive sensor for the electrochemical detection of phenol which can further broaden the applications of green silver NPs.