Zobrazení zdroje stránky Dillonluna7641

Similarly, NBLS severities in hybrid genotypes are significantly lower than those in inbred genotypes. All but four hybrid genotypes exhibit immune reaction to NBLS. In contrast, 77% of the inbred genotypes exhibit the NBLS symptoms, with disease resistance reactions ranging from susceptible (S) to resistant (R). The results demonstrate that hybrid rice is generally less susceptible to sheath blight and has a higher level of resistance against NBLS compared to inbred rice.Fusarium crown rot, caused by several species within the genus, is a major constraint that results in significant losses in wheat production worldwide. In June 2019, diseased wheat plants with typical symptoms of crown rot, including discoloration on the first two or three internodes of the stem just above the soil line and stunted, dry rotted, and discolored roots were collected in several bread wheat fields during the maturity stage in Almaty, East Kazakhstan, and Karaganda Regions of Kazakhstan. For each field, approximately twenty tillers were randomly sampled. Symptomatic tissues were surface sterilized in 1% NaClO for 2 min, rinsed with sterile distilled water three times, air-dried in a laminar flow hood, and then transferred to Petri dishes containing one-fifth strength potato dextrose agar (PDA). After incubating in the dark at 23°C for 5 days, 79 single-spore isolates showing cultural and microscopic characteristics of Fusarium were obtained on PDA and Spezieller-Nährstoffarmer agar (SNA). Colonies ity of the disease for each isolate was between 2.1 and 2.7 according to the scale of 1 to 5 described by Gebremariam et al. (2015). The pathogen was reisolated from crowns of diseased plants, but not from asymptomatic control tissues, and identified morphologically based on the methods described above, fulfilling Koch's postulates. Although several morphological features are shared by F. oxysporum and F. redolens, Baayen et al. (2001) showed that these species could be easily distinguished using molecular data. The pathogen was previously reported as F. redolens associated with crown rot of wheat in Turkey (Gebremariam et al. 2015) and Saskatchewan, Canada (Taheri et al. 2011). The presence of F. redolens causing crown rot is confirmed in the six wheat fields surveyed in Kazakhstan, for the first time. This pathogen may pose a risk for wheat production, and further studies needed to determine the impact on the crop in Kazakhstan.Chile is the main exporter of sweet cherries (Prunus avium), with a total of 228.6 thousand tons exported in the 2019-20 season, and a production from the Coquimbo to the Aysén region (http//www.iqonsulting.com/yb/). In January 2019, cherry trees from a commercial orchard located near Osorno city (40°37'S, 72°54'W), Region de Los Lagos, Chile, showed symptoms such as the presence of wood cankers, necrotic spots in leaves, and premature defoliation, with a mean disease incidence near 40%. Symptomatic leaves with necrotic spots were collected for analysis, from which all the necrotic spots were extracted by incision with a sterile scalpel, macerated in 30 mL of AFT buffer and subsequently, 100 µL of the suspension was plated on King's B (KB) agar and incubated for 48 to 72 h at 27°C, obtaining a total of two bacterial colonies identified as 7684.1 and 7684.2. Afterward, each colony was stroked in a new KB agar plate, incubated for 16 h at 27°C, and the obtained biomass was used in subsequent experiments. In KB the National Plant Protection Organization, (Servicio Agrícola y Ganadero de Chile, SAG), generating the first report of Psm race 1 in Chile. Thus, SAG established new protocols for quarantine of absent pests in the national territory (Resol. N°3080, SAG, Chile), and an immediate phytosanitary program for Psm (Resol. Exenta N°8948/2019, SAG, Chile). [https://www.selleckchem.com/products/etanercept.html Etanercept] In conclusion, our discovery contributes to the monitoring and control of the disease in Chile.Nectarine (Prunus persica (L.) Batsch var. nucipersica (Suckow) C. K. Schneid.) is a fruit crop widely cultivated throughout the Mediterranean basin. In Spain, it is mainly grown in eastern regions of the country. In March 2018, 5-year-old nectarine trees showing twig canker symptoms were observed after a rainy spring period in a 0.5 ha orchard located at Alaior, Menorca island (Spain). Cankers were frequent on affected trees (approximately, 80% of the total trees), thus leading to shoot blight. Ten twig segments of one-year old wood with cankers were cut, washed under running tap water, surface disinfected for 1 min in a 1.5% sodium hypochlorite solution and rinsed twice in sterile distilled water. Small pieces (2 mm) of affected tissues were taken from the margin of the cankers and plated on potato dextrose agar (PDA) supplemented with 0.5 g/L of streptomycin sulphate (PDAS). The plates were then incubated at 25 ºC in the dark for 7 to 10 d. Actively growing colonies were first hyphal-tipped and then transfre detected, while the controls remained asymptomatic. Diaporthe amygdali was re-isolated from symptomatic tissues and identified as described above to satisfy Koch's postulates. To our knowledge, this is the first report of D. amygdali causing twig canker and shoot blight disease on nectarine in Spain.Alfalfa (Medicago sativa L.) is an important forage crop with high nutrition for animal feed. In May 2016, a disease showing brown root rot was observed on alfalfa collected from several farms in Tongliao City (44°17' N; 121°29' E), Inner Mongolia Autonomous Region of China. The incidence of brown root rot was approximately 50 to 70% in the 2-year-old alfalfa field. Infected alfalfa exhibited varying degrees of decay in the tap root. Symptomatic roots were cut into 0.5-cm pieces, surface disinfected with 70% ethanol for 5 s and 0.1% HgCl2 for 35 s, then rinsed with sterilize distilled water three times, and placed onto potato dextrose agar (PDA) at 26°C in the dark. After 5 days, hyphal tips of the growing colonies were transferred onto PDA plates for purification. Forty-four isolates belonging to five fungal species were obtained from 20 diseased root samples. Six of the isolates resembled the genus Plectosphaerella. Colonies of these isolates were white to cream in color with sparse aerial mycelium, and then gradually became salmon pink with slimy or moist mycelium.