Search

Peanut stem rot (also known as white mold), caused by the fungus Athelia rolfsii, is one of the most damaging soilborne pathogens for U.S. peanut production. The disease is mainly controlled by fungicides and by adopting cultivars with moderate resistance. Field evaluation is the main approach for evaluating plant resistance, but it is costly and labor-intensive. Reliable methods for in vitro or greenhouse evaluations are desirable. Greenhouse, growth chamber, and in vitro methods have been tried to assess resistance, but they generally do not correlate well with field results. In this study, we developed a reliable method to assess resistance to stem rot on peanut under greenhouse conditions: stem cuttings were taken from 60-day-old plants and placed into a cup filled with potting mix. Cuttings were inoculated with active A. rolfsii mycelial plugs above the soil line, with mycelium directly contacting the stem. Inoculated cuttings were put in a mist chamber to keep humidity high. Highly significant differences of disease resistance among genotypes were found at seven days after inoculation (P< 0.05). Moreover, evaluations done at 3, 5, 7, and 9 days after inoculation and AUDPC were significantly correlated with field evaluations of the same genotypes. This greenhouse assay is a step forward to more efficiently screen peanut germplasm for stem rot resistance.

We deployed field-based high-throughput phenotyping (HTP) techniques to acquire trait data for a subset of a peanut chromosome segment substitution line (CSSL) population. Sensors mounted on an unmanned aerial vehicle (UAV) were used to derive various vegetative indices as well as canopy temperatures. A combination of aerial imaging and manual scoring showed that CSSL 100, CSSL 84, CSSL 111, and CSSL 15 had remarkably low tomato spotted wilt virus (TSWV) incidence, a devastating disease in South Georgia, USA. The four lines also performed well under leaf spot pressure. The vegetative indices showed strong correlations of up to 0.94 with visual disease scores, indicating that aerial phenotyping is a reliable way of selecting under disease pressure. Since the yield components of peanut are below the soil surface, we deployed ground penetrating radar (GPR) technology to detect pods non-destructively. Moderate correlations of up to 0.5 between pod weight and data acquired from GPR signals were observed. Both the manually acquired pod data and GPR variables highlighted the three lines, CSSL 84, CSSL 100, and CSSL 111, as the best-performing lines, with pod weights comparable to the cultivated check Tifguard. Through the combined application of manual and HTP techniques, this study reinforces the premise that chromosome segments from peanut wild relatives may be a potential source of valuable agronomic traits.

Ixekizumab is an injectable monoclonal antibody against IL-17A approved by the US Food and Drug Administration for the treatment of plaque psoriasis, psoriatic arthritis, and ankylosing spondylitis. We present what we believe is the first case of herpes zoster (shingles) in a patient 12 weeks after starting ixekizumab for presumed erythrodermic psoriasis. It is important to be aware of potential side effects of immunomodulatory medications, particularly those that are new to the market.

Transcription factors play key roles in the regulation of genes involved in normal development as well as tolerance to biotic and abiotic stresses. Specific transcription factors that are induced in peanut under drought conditions have not been identified. The objectives of this study were to compare gene-expression patterns of various transcription factors of a drought tolerant versus a susceptible peanut genotype under drought conditions and to identify transcripts that were regulated in a drought dependent manner. Twelve putative transcription factors were identified and real-time PCR analysis was performed which resulted in the identification of three unique transcripts in which ahERF1 was highly induced in the recovery stage; ahERF7 and ahERF8 were also highly induced by drought and returned to nominal levels after recovery. These sequences contain DNA binding domains that are present in the APETALA2/Ethelene Responsive Factors (AP2/ERF) family of transcription factors which have been shown to be induced by stress. Induction levels and patterns of gene-expression of ahERF1, ahERF7 and ahERF8 may be used to select plants that may have higher drought tolerance.

Meta-analytic methods were used to integrate the findings of a sample of Monte Carlo studies of the robustness of the F test in the one- and two-factor fixed effects ANOVA models. Monte Carlo results for the Welch (1947) and Kruskal-Wallis (Kruskal & Wallis, 1952) tests were also analyzed. The meta-analytic results provided strong support for the robustness of the Type I error rate of the F test when certain assumptions were violated. The F test also showed excellent power properties. However, the Type I error rate of the F test was sensitive to unequal variances, even when sample sizes were equal. The error rate of the Welch test was insensitive to unequal variances when the population distribution was normal, but nonnormal distributions tended to inflate its error rate and to depress its power. Meta-analytic and exact statistical theory results were used to summarize the effects of assumption violations for the tests.

We present THz quantum cascade emitters realized on a Si substrate. The emission centered at 3.4 and 4.9 THz originates from L-valley transitions in strain-compensated n-Type Ge/SiGe heterostructures. This is an important step towards the realization of Si-based THz quantum cascade lasers.