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Pseudocercospora angolensis is the causative agent of Pseudocercospora leaf and fruit spot disease in citrus which can result in up to 100% yield loss. Early diagnosis of this disease is vital for effective control. This study aimed at developing a loop-mediated amplification (LAMP) system for detecting P. angolensis in sweet oranges in comparison with Polymerase Chain Reaction (PCR) and using microscopy as a gold standard. Twelve non-target species were used to assess the analytical specificity of LAMP and PCR whereas the analytical sensitivity was determined using serial dilutions of P. angolensis DNA. The diagnostic accuracies of the two assays were evaluated using DNA from 150 diseased and 50 non-diseased sweet orange leaf samples. The analytical sensitivity and detection time of LAMP were of 10−4 ng/ μl and 40 minutes, respectively. The analytical sensitivity of PCR was 10ng/μl and it was specific to P. angolensis whereas three relatives of P. angolensis were detectable by LAMP. The diagnostic sensitivities of LAMP (93%) and microscopy (100%) were significantly different (X2 = 8.38, P = 0.0038) unlike the diagnostic specificities (90%) and (100%), respectively (X2 = 3.37, P = 0.066). Microscopy was significantly more sensitive than PCR (32.6%) (X2 = 149.26, P < 2.2e-16) and equally specific as PCR (P=NA). The positive predictive values of PCR and LAMP were 100% and 96.5% respectively whereas the negative predictive values were 33.1% and 81.8% respectively. The LAMP assay developed in this study offers a great tool for routine screening sweet orange samples for P. angolensis.
Patricia Driciru; M Claire Mugasa; Robert Acidri; John Adriko. Development of loop-mediated isothermal amplification (LAMP) assay for detection of Pseudocercospora angolensis in sweet orange. 2021, 1 .
AMA StylePatricia Driciru, M Claire Mugasa, Robert Acidri, John Adriko. Development of loop-mediated isothermal amplification (LAMP) assay for detection of Pseudocercospora angolensis in sweet orange. . 2021; ():1.
Chicago/Turabian StylePatricia Driciru; M Claire Mugasa; Robert Acidri; John Adriko. 2021. "Development of loop-mediated isothermal amplification (LAMP) assay for detection of Pseudocercospora angolensis in sweet orange." , no. : 1.
Coffee plants are seasonally exposed to low chilling temperatures in many coffee-producing regions. In this study, we investigated the ameliorative effects of kinetin—a cytokinin elicitor compound on the nonenzymatic antioxidants and the photosynthetic physiology of young coffee plants subjected to cold stress conditions. Although net CO2 assimilation rates were not significantly affected amongst the treatments, the subjection of coffee plants to cold stress conditions caused low gas exchanges and photosynthetic efficiency, which was accompanied by membrane disintegration and the breakdown of chlorophyll pigments. Kinetin treatment, on the other hand, maintained a higher intercellular-to-ambient CO2 concentration ratio with concomitant improvement in stomatal conductance and mesophyll efficiency. Moreover, the leaves of kinetin-treated plants maintained slightly higher photochemical quenching (qP) and open photosystem II centers (qL), which was accompanied by higher electron transfer rates (ETRs) compared to their non-treated counterparts under cold stress conditions. The exogenous foliar application of kinetin also stimulated the metabolism of caffeine, trigonelline, 5-caffeoylquinic acid, mangiferin, anthocyanins and total phenolic content. The contents of these nonenzymatic antioxidants were highest under cold stress conditions in kinetin-treated plants than during optimal conditions. Our results further indicated that the exogenous application of kinetin increased the total radical scavenging capacity of coffee plants. Therefore, the exogenous application of kinetin has the potential to reinforce antioxidant capacity, as well as modulate the decline in photosynthetic productivity resulting in improved tolerance under cold stress conditions.
Robert Acidri; Yumiko Sawai; Yuko Sugimoto; Takuo Handa; Daisuke Sasagawa; Tsugiyaki Masunaga; Sadahiro Yamamoto; Eiji Nishihara. Exogenous Kinetin Promotes the Nonenzymatic Antioxidant System and Photosynthetic Activity of Coffee (Coffea arabica L.) Plants Under Cold Stress Conditions. Plants 2020, 9, 281 .
AMA StyleRobert Acidri, Yumiko Sawai, Yuko Sugimoto, Takuo Handa, Daisuke Sasagawa, Tsugiyaki Masunaga, Sadahiro Yamamoto, Eiji Nishihara. Exogenous Kinetin Promotes the Nonenzymatic Antioxidant System and Photosynthetic Activity of Coffee (Coffea arabica L.) Plants Under Cold Stress Conditions. Plants. 2020; 9 (2):281.
Chicago/Turabian StyleRobert Acidri; Yumiko Sawai; Yuko Sugimoto; Takuo Handa; Daisuke Sasagawa; Tsugiyaki Masunaga; Sadahiro Yamamoto; Eiji Nishihara. 2020. "Exogenous Kinetin Promotes the Nonenzymatic Antioxidant System and Photosynthetic Activity of Coffee (Coffea arabica L.) Plants Under Cold Stress Conditions." Plants 9, no. 2: 281.
The current study investigates the phytochemical composition of coffee plant organs and their corresponding antioxidant capacities compared to green and roasted coffee beans. HPLC analysis indicated that the investigated compounds were present in all organs except mangiferin, which was absent in roots, stems and seeds, and caffeine, which was absent in stems and roots. Total phytochemicals were highest in the green beans (GB) at 9.70 mg g−1 dry weight (DW), while roasting caused a 66% decline in the roasted beans (RB). This decline resulted more from 5–CQA and sucrose decomposition by 68% and 97%, respectively, while caffeine and trigonelline were not significantly thermally affected. Roasting increased the total phenolic content (TPC) by 20.8% which was associated with an increase of 68.8%, 47.5% and 13.4% in the antioxidant capacity (TEAC) determined by 2,2–diphenyl–1–picryl hydrazyl radical (DPPH), 2,2–azino bis (3–ethyl benzothiazoline–6–sulphonic acid) radical (ABTS) and Ferric ion reducing antioxidant power (FRAP) assays, respectively. Amongst the leaves, the youngest (L1) contained the highest content at 8.23 mg g−1 DW, which gradually reduced with leaf age to 5.57 mg g−1 DW in the oldest (L6). Leaves also contained the highest TPC (over 60 mg g−1 GAE) and exhibited high TEAC, the latter being highest in L1 at 328.0, 345.7 and 1097.4, and least in L6 at 304.6, 294.5 and 755.1 µmol Trolox g−1 sample for the respective assays. Phytochemical accumulation, TPC and TEAC were least in woody stem (WS) at 1.42 mg g−1 DW; 8.7 mg g−1 GAE; 21.9, 24.9 and 110.0 µmol Trolox g−1 sample; while herbaceous stem (HS) contained up to 4.37 mg g−1 DW; 27.8 mg g−1 GAE; 110.9, 124.8 and 469.7 µmol Trolox g−1 sample, respectively. Roots contained up to 1.85 mg g−1 DW, 15.8 mg−1 GAE and TEAC of 36.8, 41.5 and 156.7 µmol Trolox g−1 sample. Amongst the organs, therefore, coffee leaves possessed higher values than roasted beans on the basis of phytochemicals, TPC and TEAC. Leaves also contain carotenoids and chlorophylls pigments with potent health benefits. With appropriate processing methods, a beverage prepared from leaves (coffee leaf tea) could be a rich source of phytochemicals and antioxidants with therapeutic and pharmacological values for human health.
Robert Acidri; Yumiko Sawai; Yuko Sugimoto; Takuo Handa; Daisuke Sasagawa; Tsugiyaki Masunaga; Sadahiro Yamamoto; Eiji Nishihara. Phytochemical Profile and Antioxidant Capacity of Coffee Plant Organs Compared to Green and Roasted Coffee Beans. Antioxidants 2020, 9, 93 .
AMA StyleRobert Acidri, Yumiko Sawai, Yuko Sugimoto, Takuo Handa, Daisuke Sasagawa, Tsugiyaki Masunaga, Sadahiro Yamamoto, Eiji Nishihara. Phytochemical Profile and Antioxidant Capacity of Coffee Plant Organs Compared to Green and Roasted Coffee Beans. Antioxidants. 2020; 9 (2):93.
Chicago/Turabian StyleRobert Acidri; Yumiko Sawai; Yuko Sugimoto; Takuo Handa; Daisuke Sasagawa; Tsugiyaki Masunaga; Sadahiro Yamamoto; Eiji Nishihara. 2020. "Phytochemical Profile and Antioxidant Capacity of Coffee Plant Organs Compared to Green and Roasted Coffee Beans." Antioxidants 9, no. 2: 93.
Cosmas Wacal; Naoki Ogata; Daisuke Sasagawa; Takuo Handa; Daniel Basalirwa; Robert Acidri; Tadashi Ishigaki; Sadahiro Yamamoto; Eiji Nishihara. Seed yield, crude protein and mineral nutrient contents of sesame during a two-year continuous cropping on upland field converted from a paddy. Field Crops Research 2019, 240, 125 -133.
AMA StyleCosmas Wacal, Naoki Ogata, Daisuke Sasagawa, Takuo Handa, Daniel Basalirwa, Robert Acidri, Tadashi Ishigaki, Sadahiro Yamamoto, Eiji Nishihara. Seed yield, crude protein and mineral nutrient contents of sesame during a two-year continuous cropping on upland field converted from a paddy. Field Crops Research. 2019; 240 ():125-133.
Chicago/Turabian StyleCosmas Wacal; Naoki Ogata; Daisuke Sasagawa; Takuo Handa; Daniel Basalirwa; Robert Acidri; Tadashi Ishigaki; Sadahiro Yamamoto; Eiji Nishihara. 2019. "Seed yield, crude protein and mineral nutrient contents of sesame during a two-year continuous cropping on upland field converted from a paddy." Field Crops Research 240, no. : 125-133.
Sesame is an important oilseed crop cultivated worldwide. However, research has focused on biochar effects on grain crops and vegetable and there is still a scarcity of information of biochar addition on sesame. This study was to assess the effect of biochar addition on sesame performance, with a specific emphasis on growth, yield, leaf nutrient concentration, seed mineral nutrients, and soil physicochemical properties. A field experiment was conducted on an upland field converted from paddy at Tottori Prefecture, Japan. Rice husk biochar was added to sesame cropping at rates of 0 (F), 20 (F+20B), 50 (F+50B) and 100 (F+100B) t ha−1 and combined with NPK fertilization in a first cropping and a second cropping field in 2017. Biochar addition increased plant height, yield and the total number of seeds per plant more in the first cropping than in the second cropping. The F+50B significantly increased seed yield by 35.0% in the first cropping whereas the F+20B non-significantly increased seed yield by 25.1% in the second cropping. At increasing biochar rates, plant K significantly increased while decreasing Mg whereas N and crude protein, P and Ca were non-significantly higher compared to the control. Soil porosity and bulk density improved with biochar addition while pH, exchangeable K, total N, C/N ratio and CEC significantly increased with biochar, but the effect faded in the second cropping. Conversely exchangeable Mg and its plant tissue concentration decreased due to competitive ion effect of high K from the biochar. Biochar addition is effective for increasing nutrient availability especially K for sesame while improving soil physicochemical properties to increase seed yield, growth and seed mineral quality.
Cosmas Wacal; Naoki Ogata; Daniel Basalirwa; Takuo Handa; Daisuke Sasagawa; Robert Acidri; Tadashi Ishigaki; Masako Kato; Tsugiyuki Masunaga; Sadahiro Yamamoto; Eiji Nishihara. Growth, Seed Yield, Mineral Nutrients and Soil Properties of Sesame (Sesamum indicum L.) as Influenced by Biochar Addition on Upland Field Converted from Paddy. Agronomy 2019, 9, 55 .
AMA StyleCosmas Wacal, Naoki Ogata, Daniel Basalirwa, Takuo Handa, Daisuke Sasagawa, Robert Acidri, Tadashi Ishigaki, Masako Kato, Tsugiyuki Masunaga, Sadahiro Yamamoto, Eiji Nishihara. Growth, Seed Yield, Mineral Nutrients and Soil Properties of Sesame (Sesamum indicum L.) as Influenced by Biochar Addition on Upland Field Converted from Paddy. Agronomy. 2019; 9 (2):55.
Chicago/Turabian StyleCosmas Wacal; Naoki Ogata; Daniel Basalirwa; Takuo Handa; Daisuke Sasagawa; Robert Acidri; Tadashi Ishigaki; Masako Kato; Tsugiyuki Masunaga; Sadahiro Yamamoto; Eiji Nishihara. 2019. "Growth, Seed Yield, Mineral Nutrients and Soil Properties of Sesame (Sesamum indicum L.) as Influenced by Biochar Addition on Upland Field Converted from Paddy." Agronomy 9, no. 2: 55.