Several studies have linked high phenolics/sugar ratios in the inner root bark tissue of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) to decreased susceptibility to Armillaria spp. While these studies have identified environmental factors that influence root chemistry, none have examined whether the phenolics/sugar ratio is genetically controlled. In this study, we investigated the effects of genetics and environment on the root bark chemistry of 20 families of 15-year-old Douglas-fir planted in two sites in northern Idaho. Only sugar concentrations varied significantly among families, but site was a significant source of variation for phenolics and the phenolics/sugar ratio. Family × site interactions were significant for the concentrations of all measured root bark compounds as well as for the phenolics/sugar ratio. Phenotypic correlations between height and the phenolics/sugar ratio and between height and sugar concentrations were not significant. However, families with superior height growth and below-average sugar concentrations could be found at both sites. Should a high phenolics/sugar ratio prove effective in selecting genotypes for resistance to Armillaria infection, these results suggest that gains could be made more efficiently by selecting for low sugar concentrations.
In recent years, several studies have examined the effect of microfibril angle (MFA) on wood quality. However, little research has been conducted upon the genetic mechanisms controlling MFA. In this study, we examined the heritability of MFA in loblolly pine, Pinus taeda L.,and its genetic relationships with height, diameter, volume, and specific gravity. Increment cores were collected at breast height from 20 to 25 progeny from each of 12 to 17 crosses (among 11 parents) in two modified partial-diallels in different locations in southern Arkansas. Specific gravitywas measured on segments containing rings 1 through 5 and on segments containing rings 6 through 20. MFA was measured on the earlywood and latewood sections of rings 4, 5, 19, and 20. Rings 4 and 5 were chosen as representative of core wood and rings 19 and 20 as representative of outer wood. Analyses of variance revealed statistically significant genetic and environmental influences on MFA. Significant general combining ability (GCA), specific combining ability (SCA), and SCA × block effects indicated that there are both additive and nonadditive genetic influences on MFA. Individual-tree, narrow-sense heritability estimates were variable, ranging from 0.17 for earlywood (ring) 4 MFA to 0.51 for earlywood (ring) 20 MFA. Genetic correlations between MFA, specific gravity, and the growth traits were nonsignificant due to large estimated standard errors. South.J. Appl. For. 28(4):196–204.
ImportanceThe prevalence of urinary tract infection (UTI), bacteremia, and bacterial meningitis in febrile infants with SARS-CoV-2 is largely unknown. Knowledge of the prevalence of these bacterial infections among febrile infants with SARS-CoV-2 can inform clinical decision-making.ObjectiveTo describe the prevalence of UTI, bacteremia, and bacterial meningitis among febrile infants aged 8 to 60 days with SARS-CoV-2 vs without SARS-CoV-2.Design, Setting, and ParticipantsThis multicenter cross-sectional study was conducted as part of a quality improvement initiative at 106 hospitals in the US and Canada. Participants included full-term, previously healthy, well-appearing infants aged 8 to 60 days without bronchiolitis and with a temperature of at least 38 °C who underwent SARS-CoV-2 testing in the emergency department or hospital between November 1, 2020, and October 31, 2022. Statistical analysis was performed from September 2022 to March 2023.ExposuresSARS-CoV-2 positivity and, for SARS-CoV-2–positive infants, the presence of normal vs abnormal inflammatory marker (IM) levels.Main Outcomes and MeasuresOutcomes were ascertained by medical record review and included the prevalence of UTI, bacteremia without meningitis, and bacterial meningitis. The proportion of infants who were SARS-CoV-2 positive vs negative was calculated for each infection type, and stratified by age group and normal vs abnormal IMs.ResultsAmong 14 402 febrile infants with SARS-CoV-2 testing, 8413 (58.4%) were aged 29 to 60 days; 8143 (56.5%) were male; and 3753 (26.1%) tested positive. Compared with infants who tested negative, a lower proportion of infants who tested positive for SARS-CoV-2 had UTI (0.8% [95% CI, 0.5%-1.1%]) vs 7.6% [95% CI, 7.1%-8.1%]), bacteremia without meningitis (0.2% [95% CI, 0.1%-0.3%] vs 2.1% [95% CI, 1.8%-2.4%]), and bacterial meningitis (<0.1% [95% CI, 0%-0.2%] vs 0.5% [95% CI, 0.4%-0.6%]). Among infants aged 29 to 60 days who tested positive for SARS-CoV-2, 0.4% (95% CI, 0.2%-0.7%) had UTI, less than 0.1% (95% CI, 0%-0.2%) had bacteremia, and less than 0.1% (95% CI, 0%-0.1%) had meningitis. Among SARS-CoV-2–positive infants, a lower proportion of those with normal IMs had bacteremia and/or bacterial meningitis compared with those with abnormal IMs (<0.1% [0%-0.2%] vs 1.8% [0.6%-3.1%]).Conclusions and RelevanceThe prevalence of UTI, bacteremia, and bacterial meningitis was lower for febrile infants who tested positive for SARS-CoV-2, particularly infants aged 29 to 60 days and those with normal IMs. These findings may help inform management of certain febrile infants who test positive for SARS-CoV-2.
Currently, both industrial and private landowners in the Western Gulf Forest Tree Improvement Program (WGFTIP) area are compensated for their timber primarily based on the weight or volume of green wood reaching the mill gate. This places an immediate economic focus on adaptability and volume growth. However, selection for volume growth alone could result in decreased wood quality over time. Wood quality characteristics including stem straightness, wood specific gravity, and microfibril angle have either neutral or slightly unfavorable genetic correlations with volume growth in the WGFTIP loblolly pine (Pinus taeda L.) program. Since most WGFTIP members also consider wood quality an important selection criterion, the WGFTIP must define the best possible set of selection criteria given that (1) no single set of breeding objectives can be considered optimal for multiple products and (2) improvement in wood quality has no readily recognized economic importance in the existing market. To meet this challenge, the WGFTIP has implemented different strategies for its mainline breeding and deployment populations. In the mainline population, consistent breedng and selection criteria are used across members, while in the various deployment populations, selections are tailored to meet the specific needs of each member. The WGFTIP is also developing an elite wood quality population (WQEPop) based on backward selection. For the WQEPop to be successful, the economic importance of improved wood quality must be recognized, and landowners must be compensated for growing higher quality timber, especially if this results in reduced volume production. Improved methodology for within-family selection and for wood quality trait measurement is also important.
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