Registration of N614, A3N615, N616, and N617 Shattercane Genetic Stocks with Cytoplasmic or Nuclear Male Sterility and Juicy or Dry Midribs

Four shattercane [Sorghum bicolor subsp. drummondii (Nees ex Steud.) de Wet ex Davidse] genetic stocks—N614 (Reg. No. GS-652, PI 665684), A3N615 (Reg. No. GS-651, PI 665683), N616 (Reg. No. GS-653, PI 665685), and N617 (Reg. No. GS-654, PI 665686)—with A3 cytoplasmic male sterility or the nuclear male sterility gene ms3 containing either juicy (dd) or dry (DD) culms were developed jointly by the USDA-ARS; the Iowa Agricultural and Home Economics Experiment Station, College of Agriculture and Life Sciences, Iowa State University; and the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska. The stocks were released in July 2011. The source material for these genetic stocks was isolated from an archetypical shattercane population found near Lincoln, NE. Release of these genetic stocks makes available shattercane lines with both A3 cytoplasmic male sterility, and ms3 genetic (nuclear) male sterility to facilitate crossing. These genetic stocks also contain juicy (dd) or dry (DD) culms, a visible genetic marker to facilitate screening progeny resulting from crosses. The genetic stocks have immediate application for basic research involving gene flow from cultivated sorghum [Sorghum bicolor (L.) Moench] to shattercane and on the fitness of offspring resulting from such crosses

Wheat Cultivar-Specific Selection of 2,4-Diacetylphloroglucinol-Producing Fluorescent \u3ci\u3ePseudomonas\u3c/i\u3e Species from Resident Soil Populations

An emerging body of evidence indicates a role for plant genotype as a determinant of the species and genetic composition of the saprophytic microbial community resident to the rhizosphere. In this study, experiments were conducted to determine the capacity of five different wheat cultivars to enhance resident populations and support introduced strains of 2,4-diacetylphloroglucinol (2,4-DAPG)-producing fluorescent pseudomonads, a group of bacteria known to provide biological control of several soilborne diseases. When soils were cropped with three successive 28-day growth cycles of wheat, the 2,4- DAPG-producing strains were consistently recovered from the rhizosphere of the cultivar Lewjain, and commonly were present at populations higher than those recovered from other wheat cultivars. Based on restriction fragment length polymorphism and sequence analyses of phlD, a key gene involved in 2,4-DAPG production, two previously undefined phlD+ genotypes, referred to as genotypes PfZ and PfY, were discovered. Wheat cultivar Lewjain was the primary source of genotype PfY while cultivar Penawawa yielded the majority of genotype PfZ. Based on 16S rDNA sequence analysis, both new phlD genotypes were classified as P. fluorescens. Comparison of the rhizosphere competence of 2,4-DAPG-producing P. fluorescens Q2-87 (genotype B) and P. fluorescens LR3-A28 (genotype PfY) showed that both strains persisted at similar populations in the rhizosphere of all cultivars tested over a 30 day period when introduced as a seed inoculant. However, when strain LR3-A28 was applied as a soil inoculant, this strain was recovered at higher populations from the rhizosphere of wheat cultivar Lewjain than from the rhizospheres of two other cultivars. No cultivar effects were shown for strain Q2-87. Collectively, these results add further to evidence indicating a degree of specificity in interactions between plant cultivars and specific members of the saprophytic microbial community. Furthermore, as 2,4- DAPG-producing fluorescent Pseudomonas spp. have a central role in the spontaneous reduction in severity of take-all disease of wheat in response to continuous wheat monoculture, we postulate that the use of specific cultivars, such as Lewjain, which possess a superior capacity to enhance resident soil populations of these bacteria may have potential to reduce the length of the monoculture period required to induce natural suppressiveness of soils toward this disease

Wheat Cultivar-Specific Selection of 2,4-Diacetylphloroglucinol-Producing Fluorescent \u3ci\u3ePseudomonas\u3c/i\u3e Species from Resident Soil Populations

An emerging body of evidence indicates a role for plant genotype as a determinant of the species and genetic composition of the saprophytic microbial community resident to the rhizosphere. In this study, experiments were conducted to determine the capacity of five different wheat cultivars to enhance resident populations and support introduced strains of 2,4-diacetylphloroglucinol (2,4-DAPG)-producing fluorescent pseudomonads, a group of bacteria known to provide biological control of several soilborne diseases. When soils were cropped with three successive 28-day growth cycles of wheat, the 2,4- DAPG-producing strains were consistently recovered from the rhizosphere of the cultivar Lewjain, and commonly were present at populations higher than those recovered from other wheat cultivars. Based on restriction fragment length polymorphism and sequence analyses of phlD, a key gene involved in 2,4-DAPG production, two previously undefined phlD+ genotypes, referred to as genotypes PfZ and PfY, were discovered. Wheat cultivar Lewjain was the primary source of genotype PfY while cultivar Penawawa yielded the majority of genotype PfZ. Based on 16S rDNA sequence analysis, both new phlD genotypes were classified as P. fluorescens. Comparison of the rhizosphere competence of 2,4-DAPG-producing P. fluorescens Q2-87 (genotype B) and P. fluorescens LR3-A28 (genotype PfY) showed that both strains persisted at similar populations in the rhizosphere of all cultivars tested over a 30 day period when introduced as a seed inoculant. However, when strain LR3-A28 was applied as a soil inoculant, this strain was recovered at higher populations from the rhizosphere of wheat cultivar Lewjain than from the rhizospheres of two other cultivars. No cultivar effects were shown for strain Q2-87. Collectively, these results add further to evidence indicating a degree of specificity in interactions between plant cultivars and specific members of the saprophytic microbial community. Furthermore, as 2,4- DAPG-producing fluorescent Pseudomonas spp. have a central role in the spontaneous reduction in severity of take-all disease of wheat in response to continuous wheat monoculture, we postulate that the use of specific cultivars, such as Lewjain, which possess a superior capacity to enhance resident soil populations of these bacteria may have potential to reduce the length of the monoculture period required to induce natural suppressiveness of soils toward this disease

Ammonium Fluoride as a Hydrogen-disordering Agent for Ice

The removal of residual hydrogen disorder from various phases of ice with acid or base dopants at low temperatures has been a focus of intense research for many decades. As an antipode to these efforts, we now show using neutron diffraction that ammonium fluoride (NH4F) is a hydrogen-disordering agent for the hydrogen-ordered ice VIII. Cooling its hydrogen-disordered counterpart ice VII doped with 2.5 mol% ND4F under pressure leads to a hydrogen-disordered ice VIII with ~31% residual hydrogen disorder illustrating the long-range hydrogen-disordering effect of ND4F. The doped ice VII could be supercooled by ~20 K with respect to the hydrogen-ordering temperature of pure ice VII after which the hydrogen-ordering took place slowly over a ~60 K temperature window. These findings demonstrate that ND4F-doping slows down the hydrogen-ordering kinetics quite substantially. The partial hydrogen order of the doped sample is consistent with the antiferroelectric ordering of pure ice VIII. Yet, we argue that local ferroelectric domains must exist between ionic point defects of opposite charge. In addition to the long-range effect of NH4F-doping on hydrogen-ordered water structures, the design principle of using topological charges should be applicable to a wide range of other 'ice-rule' systems including spin ices and related polar materials.Comment: 23 pages, 4 figures, 2 table

Ultra-low pressure hydrocephalic state in NPH: benefits of therapeutic siphoning with adjustable anti-gravity valves

Background: Idiopathic normal-pressure hydrocephalus (NPH) is a condition of the elderly treated by ventriculoperitoneal shunt (VP) insertion. A subset of NPH patients respond only temporarily to shunt insertion despite low valve opening pressure. This study aims to describe our experience of patients who benefit from further CSF drainage by adding adjustable antigravity valves and draining CSF at ultra-low pressure. Methods: Single-centre retrospective case series of patients undergoing shunt valve revision from an adjustable differential pressure valve with fixed antigravity unit to a system incorporating an adjustable gravitational valve (Miethke proSA). Patients were screened from a database of NPH patients undergoing CSF diversion over 10 consecutive years (April 2008–April 2018). Clinical records were retrospectively reviewed for interventions and clinical outcomes. Results Nineteen (10F:9M) patients underwent elective VP shunt revision to a system incorporating an adjustable gravitational valve. Mean age 77.1 ± 7.1 years (mean ± SD). Eleven patients (58%) showed significant improvement in walking speed following shunt revision. Fourteen patients/carers (74%) reported subjective improvements in symptoms following shunt revision. Conclusions: Patients presenting symptoms relapse following VP shunting may represent a group of patients with ultra-low-pressure hydrocephalus, for whom further CSF drainage may lead to an improvement in symptoms. These cases may benefit from shunt revision with an adjustable gravitational valve, adjustment of which can lead to controlled siphoning of CSF and drain CSF despite ultra-low CSF pressure

Occurrence of the Waxy Alleles \u3ci\u3ewxa\u3c/i\u3e and \u3ci\u3ewxb\u3c/i\u3e in Waxy Sorghum Plant Introductions and Their Effect on Starch Thermal Properties

The existence of two waxy alleles, wxa associated with no detectable granule bound starch synthase (GBSS) and wxb associated with apparently inactive GBSS, was recently reported in sorghum [Sorghum bicolor (L.) Moench]. In this paper, the occurrence of the wxa and wxb alleles in the USDA-ARS photoperiod-insensitive sorghum collection was determined, and the effects of the wxa and wxballeles on thermal properties of sorghum starch (gelatinization temperatures and energy requirements) measured by differential scanning calorimetry. Of the 51 purported waxy accessions examined, 14 tested positive for presence of amylose by iodine staining and were considered to be previously misclassified wild type lines. Nine accessions were mixed for presence or absence of amylose. Twenty-four of the 28 accessions confirmed to be waxy by negative iodine staining for amylose had no detectable GBSS using sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) (wxa), and four were show to contain GBSS (wxb). Mean gelatinization onset, peak, and end temperatures were significantly lower for wild-type than either of the two waxy genotypes. Mean gelatinization onset temperature was slightly higher for waxy-GBSS+ genotypes than waxy-GBSS− genotypes. Mean gelatinization end temperature was slightly higher for waxy-GBSS− genotypes than waxy-GBSS+ genotypes. Significant genetic variation was observed within genotypic classes, suggesting influence of additional modifier genes affecting sorghum starch structure or micro-environmental effects

Occurrence of the Waxy Alleles \u3ci\u3ewxa\u3c/i\u3e and \u3ci\u3ewxb\u3c/i\u3e in Waxy Sorghum Plant Introductions and Their Effect on Starch Thermal Properties

The existence of two waxy alleles, wxa associated with no detectable granule bound starch synthase (GBSS) and wxb associated with apparently inactive GBSS, was recently reported in sorghum [Sorghum bicolor (L.) Moench]. In this paper, the occurrence of the wxa and wxb alleles in the USDA-ARS photoperiod-insensitive sorghum collection was determined, and the effects of the wxa and wxballeles on thermal properties of sorghum starch (gelatinization temperatures and energy requirements) measured by differential scanning calorimetry. Of the 51 purported waxy accessions examined, 14 tested positive for presence of amylose by iodine staining and were considered to be previously misclassified wild type lines. Nine accessions were mixed for presence or absence of amylose. Twenty-four of the 28 accessions confirmed to be waxy by negative iodine staining for amylose had no detectable GBSS using sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) (wxa), and four were show to contain GBSS (wxb). Mean gelatinization onset, peak, and end temperatures were significantly lower for wild-type than either of the two waxy genotypes. Mean gelatinization onset temperature was slightly higher for waxy-GBSS+ genotypes than waxy-GBSS− genotypes. Mean gelatinization end temperature was slightly higher for waxy-GBSS− genotypes than waxy-GBSS+ genotypes. Significant genetic variation was observed within genotypic classes, suggesting influence of additional modifier genes affecting sorghum starch structure or micro-environmental effects

Expression of the tobacco β- 1,3-glucanase gene, PR-2d, following induction of SAR with \u3ci\u3ePeronospora tabacina\u3c/i\u3e

Systemic acquired resistance (SAR) is induced following inoculation of Peronospora tabacina sporangia into the stems of Nicotiana tabacum plants highly susceptible to the pathogen. Previous results have shown that accumulation of acidic P-1,3-glucanases (PR-2\u27s) following induction of SAR by P. tabacina may contribute to resistance to P. tabacina. We showed that up-regulation of the PR-2 gene, PR-2d, following stem inoculation with P. tabacina, is associated with SAR. Studies using plants transformed with GUS constructs containing the full length promoter from PR-2d or promoter deletions, provided evidence that a previously characterized regulatory element that is involved in response to salicylic acid (SA), may be involved in regulation of PR-2d following induction of SAR with P. tabacina. This work provides evidence that regulation of PR-2 genes during P. tabacina-induced SAR may be similar to regulation of these genes during infection of N-gene tobacco by TMV or following exogenous application of SA, and provides further support for the role of SA in regulation of genes during P. tabacina-induced SAR

Field damage of sorghum (\u3ci\u3eSorghum bicolor\u3c/i\u3e) with reduced lignin levels by naturally occurring insect pests and pathogens

Sorghum (Sorghum bicolor (L.) Moench) brown midrib (bmr) mutant lines have reduced levels of lignin, which is a potentially useful trait for bioenergy production, but the effects of this trait on insect and plant pathogen interactions are unknown under field conditions. Field-grown bmr6, bmr12, and wild-type (WT) plants were examined for insect and disease damage. In most cases, observed frequency, population, or leaf area damage caused by insects or pathogens on bmr6 or bmr12 plants were not greater than those observed on WT plants in the field or laboratory assays. European corn borers [Ostrinia nubilalis (Hübner)(Lepidoptera: Pyralidae)] often caused lower amounts of leaf damage to bmr6 leaves compared to bmr12 and sometimes WT leaves in the field study. Leaf damage by corn earworms [Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)] and fall armyworms [Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)] in laboratory assays was often lower for bmr versus WT leaves. Incidence of disease lesions was significantly higher on bmr6 compared to WT plants for one of three samplings in 2011, but the opposite trend was observed overall in 2012 and no significant differences were noted in 2013. When corn earworms and fall armyworms were fed the excised pith, bmr6 and/or bmr12 pith caused significant morality to one or both insect species in all 3 years. Damage variability between the 3 years may have been due to hotter and drier than normal conditions in 2012. Thus, bmr lines of sorghum suitable for bioenergy production have potential for sustainable production in the field