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Keith Woeste - One of the best experts on this subject based on the ideXlab platform.
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pollen flow and paternity in an isolated and non isolated black walnut Juglans nigra l timber seed orchard
PLOS ONE, 2018Co-Authors: Aziz Ebrahimi, Keith Woeste, Mark V Coggeshall, Shaneka S Lawson, Graham S Frank, James R MckennaAbstract:Artificial pollination of black walnut (Juglans nigra L.) is not practical and timber breeders have historically utilized only open-pollinated half-sib families. An alternate approach called “breeding without breeding,” consists of genotyping open-pollinated progeny using DNA markers to identify paternal parents and then constructing full-sib families. In 2014, we used 12 SSR markers to genotype 884 open-pollinated half-sib progeny harvested from two clonal orchards containing 206 trees, comprised of 52 elite timber selections. Seed was harvested in 2011 from each of two ramets of 23 clones, one upwind and one downwind, based on prevailing wind direction from the west—southwest. One orchard was isolated from wild black walnut and composed of forward selections while the other orchard was adjacent to a natural forest containing mature black walnut composed of backward selections. Isolation significantly increased within-orchard pollination (85%) of the progeny from the isolated orchard compared to 42% from the non-isolated orchard. Neither prevailing wind direction nor seed tree position in the orchard affected paternity patterns or wild pollen contamination. Genetic diversity indices revealed that progeny from both orchards were in Hardy–Weinberg equilibrium with very little inbreeding and no selfing. A significant level of inbreeding was present among the forward selected parents, but not the first generation (backward selected) parents. Some orchard clones failed to sire any progeny while other clones pollinated upwards of 20% of progeny.
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localized gene expression changes during adventitious root formation in black walnut Juglans nigra l
Tree Physiology, 2018Co-Authors: Micah E Stevens, Keith Woeste, Paula M PijutAbstract:Cutting propagation plays a large role in the forestry and horticulture industries where superior genotypes need to be clonally multiplied. Integral to this process is the ability of cuttings to form adventitious roots. Recalcitrance to adventitious root development is a serious hurdle for many woody plant propagation systems including black walnut (Juglans nigra L.), an economically valuable species. The inability of black walnut to reliably form adventitious roots limits propagation of superior genotypes. Adventitious roots originate from different locations, and root induction is controlled by many environmental and endogenous factors. At the molecular level, however, the regulation of adventitious root formation is still poorly understood. In order to elucidate the transcriptional changes during adventitious root development in black walnut, we used quantitative real-time polymerase chain reaction to measure the expression of nine key genes regulating root formation in other species. Using our previously developed spatially explicit timeline of adventitious root development in black walnut softwood cuttings, we optimized a laser capture microdissection protocol to isolate RNA from cortical, phloem fiber and phloem parenchyma cells throughout adventitious root formation. Laser capture microdissection permitted high-resolution, site-specific analysis of gene expression that differentiated between participatory and non-participatory root progenitor cells. Results indicated mRNA abundance was altered in all nine rooting-related genes in response to auxin treatment in both juvenile and mature cuttings. SCARECROW LIKE-1 (SCL) had the greatest change in expression in juvenile rooting-competent cells at days 16 and 18, with a 24- and 23-fold increase relative to day 0, respectively. Tissues not linked to root organogenesis had little change in SCL expression at similar time points. AUXIN RESPONSE FACTOR (ARF)6 and ARF8 as well as SHORTROOT expression also increased 2- to 4-fold in rooting-competent tissue. The greatest transcript abundance in rooting-competent cuttings was restricted to root progenitor cells, while recalcitrant cuttings had a diffuse mRNA signal among tissue types.
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discrimination and assessment of black walnut Juglans nigra l cultivars using phenology and microsatellite markers ssrs
Canadian Journal of Plant Science, 2017Co-Authors: Peng Zhao, Mark V Coggeshall, Huijuan Zhou, Bill Reid, Keith WoesteAbstract:Black walnut ( Juglans nigra L.), a large tree native throughout the eastern United States, produces a high quality edible nut. Our goal was to maintain the integrity of the black walnut breeding programs by verifying the identity of accessions. We sampled 285 ramets of 78 cultivars from the black walnut nut breeding orchards and clonal repositories at the University of Missouri and Kansas State University. We employed both phenotypic and genotypic methods to identify and differentiate cultivars. Phenotypes were evaluated using seven phenological traits. Cultivars varied for all traits among each of the four years, but the best morphological characteristics for evaluating cultivar identity were bud break date and date of first pistillate bloom. Samples (n=285) were genotyped using ten polymorphic microsatellite loci. The SSRs produced a total of 174 alleles and 17.2 alleles per locus. We detected forty-seven unique genotypes represented by more than one sample, including 128 instances of identical g...
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cultivar identification and genetic relatedness among 25 black walnut Juglans nigra clones based on microsatellite markers
In: Kabrick John M.; Dey Daniel C.; Knapp Benjamin O.; Larsen David R.; Shifley Stephen R.; Stelzer Henry E. eds. Proceedings of the 20th Central Hard, 2017Co-Authors: Kejia Pang, Keith Woeste, Charles H MichlerAbstract:A set of eight microsatellite markers was used to genotype 25 black walnut (Juglans nigra L.) clones within the Purdue University germplasm repository. The identities of 212 ramets were verified using the same eight microsatellite markers. Some trees were mislabeled and corrected as to clone using analysis of microsatellite markers. A genetic dendrogram was constructed to show the degree of genetic relatedness between clones. Two additional dendrograms, one based on crown architecture traits and the other on tree size and form traits, were also built and compared with the genetic dendrogram. The genetic dendrogram showed that these eight molecular markers had the ability to distinguish genetically related clones from less related ones. Crown architecture traits and tree size and form traits were able to group genetically related clones together, but less accurately than the genetic matrix.
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developing new microsatellite markers in walnut Juglans regia l from Juglans nigra genomic ga enriched library
Ekin Journal of Crop Breeding and Genetics. 1-2: 93-99., 2015Co-Authors: Hayat Topcu, Keith Woeste, Nergiz Coban, Mehmet Sutyemez, Salih KafkasAbstract:We attempted to develop new polymorphic SSR primer pairs in walnut using sequences derived from Juglans nigra L. genomic enriched library with GA repeat. The designed 94 SSR primer pairs were subjected to gradient PCR in 12 walnut cultivars to determine their optimum annealing temperatures and to determine whether they produce bands. Then, the primer pairs which had amplification in agarose gel were analyzed in capillary electrophoresis to determine their allele sizes. According to the gradient PCR and capillary electrophoresis results, 60.6% of the SSR primer pairs did not amplify any bands in agarose gel. Rest of the 37 primer pairs produced bands and their annealing temperatures and allele sizes were determined. From the amplified primer pairs, 18 of them were monomorphic, while 19 of them were polymorphic. As a result, 20.2% polymorphism was obtained from 94 SSR primer pairs tested in this study which had lower ratio when compared to the literature.
Douglass F Jacobs - One of the best experts on this subject based on the ideXlab platform.
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nitrogen fertilization of black walnut Juglans nigra l during plantation establishment physiology of production
European Journal of Forest Research, 2014Co-Authors: Juan A Oliet, Rosa C Goodman, Joshua L Sloan, Douglass F JacobsAbstract:Physiological mechanisms by which nitrogen (N) fertilization affects growth and development in temperate deciduous forest trees are not clearly understood, especially under intensive silvicultural systems. Grafted, Tippecanoe 1 cultivar black walnut (Juglans nigra L.) trees were grown in an intensively managed plantation in west-central Spain and subjected to six, fixed-nutrient-ratio complete fertilizer treatments (defined as 0, 25, 50, 75, 150, and 300 g N tree−1) delivered via daily fertigation. Leaf chemistry and morphology were evaluated from June to September, and gas exchange was measured in July. Specific leaf mass, leaflet nitrogen (N), and chlorophyll concentrations varied over the course of the growing season, yet consistently increased with increasing fertilization. Net photosynthesis at ambient (Anet) and light-saturated (Amax) conditions increased from the unfertilized control to lowest treatment (25 g N) but did not increase at higher fertilizer rates. Photosynthetic N and chlorophyll use efficiencies decreased with increasing fertilization, but photosynthetic phosphorus and water use efficiencies increased. Transpiration rates and dark respiration were not significantly affected by treatment. Overall, the lowest fertilizer treatment (25 g N) had the greatest photosynthetic efficiency. Interactions between N and other nutrients with increasing fertilizer application suggested potential for nutrient imbalances at high fertilization rates. Our results provide a physiological justification for the use of low-to-moderate fertilization as an efficient strategy to promote black walnut plantation establishment under intensive cultural systems.
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chlorophyll fluorescence of stem cambial tissue reflects dormancy development in Juglans nigra seedlings
New Forests, 2012Co-Authors: Barrett C Wilson, Douglass F JacobsAbstract:Assessment of chlorophyll fluorescence (CF) of forest tree seedlings can provide important insight into physiological function, dormancy status, and stress resistance. This evaluative tool has been measured routinely using foliage on conifer seedlings to assess seedling physiological status during winter dormancy. Absence of foliage during dormancy has thus far precluded the potential application of CF to seedling quality assessment of temperate deciduous hardwood seedlings. Because stems contain chlorophyll, however, assessment of CF using stem tissue may serve as an effective alternative tissue type to facilitate CF measurements. We collected Juglans nigra L. (black walnut) seed from two provenances (Alabama and Indiana, USA) and subjected 1-year-old container seedlings from these provenances to a simulated hardening regime (i.e., progressively decreasing temperatures and photoperiods) in a growth chamber environment over an 18-week period; CF of stem tissue (evaluated as ΦPSII, efficiency of photosystem II) was sampled periodically at seven time intervals. Though both provenance and measurement period significantly affected ΦPSII, measurement period had a much more pronounced effect. Values for ΦPSII fluctuated (ranging from 0.45 to 0.72) during the simulated growth and hardening regimes, generally decreasing over time for both provenances. Our results suggest that physiological status of temperate deciduous seedlings may be effectively evaluated during dormancy by assessing CF of stem tissue.
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half sib seed source and nursery sowing density affect black walnut Juglans nigra growth after 5 years
New Forests, 2011Co-Authors: Keith Woeste, Douglass F Jacobs, J R MckennaAbstract:The effect of seed source (half-sib family) and nursery bed density on the nursery stock quality and subsequent growth of black walnut (Juglans nigra L.) was investigated. Nine black walnut female genitors were selected to represent a range of phenotypes. Seeds were collected, cleaned, cold-treated, and pre-sprouted to ensure that germination was uniform and complete. The pre-sprouted seeds were planted in a randomized complete block design into standard nursery beds in Indiana, USA at three sowing densities, (11.2 plants m−2; 24.2 plants m−2; 29.4 plants m−2). After lifting, the trees were measured for height, ground-line diameter and root volume and then planted into a plantation in a randomized complete block design and re-measured after 1 and 5 years of growth. One year after planting, the effects of family (half-sib seed source) and density were significant or very highly significant for seedling height, and ground-line diameter, although family effects were greater than those for density, especially at moderate and high nursery bed density. After 5 years of growth, the same effects contributed significantly to ground-line diameter and dbh, but only family significantly influenced height. Family was more important than nursery bed density in determining the size of the trees after 5 years. Although there were no significant family × density interactions after 5 years, family variance for all the traits was considerably higher among seedlings grown at moderate and high density in the nursery. Phenotypic correlations among traits within and among years were generally very high (0.65 < r < 0.90) and insensitive to planting density in the nursery.
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ecophysiological responses of black walnut Juglans nigra to plantation thinning along a vertical canopy gradient
Forest Ecology and Management, 2010Co-Authors: Martinmichel Gauthier, Douglass F JacobsAbstract:Abstract Ecophysiology of black walnut ( Juglans nigra L.) along a vertical canopy gradient was studied in a mixed species plantation for the first (2007) and second (2008) growing seasons after thinning to understand response mechanisms to increased resource availability. Parameters were affected by the thinning treatment in 2008 only. Thinned trees showed increased light-saturated maximum photosynthesis ( A max ) from 2007 to 2008 compared to non-thinned trees. This response was likely due to increased light levels near thinned trees (vs. changes in water or nutrient status), because thinning did not affect midday leaf water potential ( Ψ md ), average daily soil water content (SWC), or leaf nitrogen content per unit area ( N a ). Plantation thinning did not increase relative diameter growth during the experimental period. This may be due to low thinning intensity and mortality prior to thinning that reduced competition from first-tier neighbors. Certain leaf traits such as leaf mass per unit area (LMA) and N a increased from the bottom to the upper canopy position, but did not influence thinning responses. Distribution patterns of photosynthetic parameters through the vertical canopy gradient were less defined than leaf structural traits such as LMA and N a . Findings reflect black walnut's large variability in response to thinning.
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short term physiological responses of black walnut Juglans nigra l to plantation thinning
Forest Science, 2009Co-Authors: Martinmichel Gauthier, Douglass F JacobsAbstract:We studied physiological responses of mature black walnut (Juglans nigra L.) trees to determine the time necessary for photosynthetic adaptation to plantation thinning. Measurements were taken before treatment (July 25, 2007) and for the first 3 days after thinning (July 29, 30, and 31, 2007). Measurements did not continue in August because trees had developed leaf anthracnose and senescence was occurring, but measurements resumed on May 29, 2008 and July 29, 2008. Repeated measures of net photosynthetic rates (A) showed that thinned trees did not respond immediately to partial release, but nearly doubled in A compared with a 35% increase in control trees 1 year after thinning. Significant increases in light, leaf water status, relative humidity of the air, and nitrogen content per unit leaf area were also found in thinned trees 1 year after treatment. From these variables, light (r 0.79) showed the strongest relationship with A. Results suggest that black walnut requires a full growing season before it responds to treatment when thinned late in the growing season. Thinning earlier, such as in June, may trigger a more rapid adaptation in A of thinned trees that was not detected in our study. FOR. SCI. 55(3):221–229.
Christian Jayallemand - One of the best experts on this subject based on the ideXlab platform.
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cdka orthologue isolation and its expression during cambial activity in hybrid walnut Juglans nigra Juglans regia
Trees-structure and Function, 2003Co-Authors: Nadia Goue, Christian Jayallemand, Gregory Montiel, Isabelle Levert, Muriel Gaudet, Philippe LabelAbstract:Improved wood production is a major aim for walnut forests and especially for hybrid walnut (Juglans nigra×Juglans regia). This paper presents the first report describing the structure and function of a CDKA gene potentially involved in radial growth and wood production in walnut. We report the isolation of the full sequence of a CDKA gene by the use of degenerate primers and RACE approaches. We also describe the expression of the CDKA gene during radial growth. The analysis of intron sizes and positions as well as Southern-blot analysis suggest the presence of multiple copies (more than 2) of the CDKA gene in the hybrid walnut genome. Two different promoter sequences were cloned by the use of two different second-intron-specific primers.
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expression of genes encoding chalcone synthase flavanone 3 hydroxylase and dihydroflavonol 4 reductase correlates with flavanol accumulation during heartwood formation in Juglans nigra
Tree Physiology, 2002Co-Authors: Isacco Beritognolo, Christian Jayallemand, Jeanpaul Charpentier, Elisabeth Magel, Amani Abdellatif, Christian BretonAbstract:Summary Heartwood formation is generally characterized by the accumulation of phenolic substances that increase the natural color and durability of wood. Although there is evidence that these substances are synthesized in aging sapwood cells, little is known about heartwood formation at the molecular level. We monitored seasonal changes in flavanol concentration across the stems of 23-year-old Juglans nigra L. trees by sampling growth rings extending from the differentiating xylem to the heartwood. We also analyzed expression of phenylpropanoid and flavonoid structural genes in these samples. In the sapwood–heartwood transition zone, flavanol accumulation was correlated with the transcription levels of the chalcone synthase (CHS) and flavanone 3-hydroxylase (F3H) genes. We also observed correlations between flavanol accumulation and the amount of dihydroflavonol 4-reductase (DFR) gene transcript in October, January and May. Although transcription of phenylalanine ammonia-lyase (PAL) and 4-coumarate:CoA ligase (4CL) genes did not correlate with flavanol accumulation, PAL genes were strongly expressed in the transition zone of samples collected in autumn, suggesting that their transcription in these tissues contributes to phenolic biosynthesis. Western immunoblotting showed that accumulation of CHS protein correlated with the amount of CHS gene transcript, whereas accumulation of PAL protein did not correlate with the the transcription levels PAL genes. Preliminary analyses revealed that PAL and CHS activities were higher in the transition zone than in the inner sapwood in autumn, winter, and spring. Thus, CHS activity could be regulated mainly at the transcriptional level, whereas post-translational modifications could modulate PAL activity. We conclude that flavanols are synthesized de novo in J. nigra sapwood cells that are undergoing transformation to heartwood.
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modifications of hybrid walnut Juglans nigra 23 x Juglans regia wood colour and phenolic composition under various steaming conditions
Holzforschung, 2000Co-Authors: Patricia Burtin, Christian Jayallemand, Jeanpaul Charpentier, Gerard JaninAbstract:The effects of steaming were studied on Walnut wood from a hybrid (Juglans nigra 23 x J. regia) tree in terms of wood colour and phenolic composition. Wood samples were subjected to treatments at 75. 100 and 125°C for 4, 8, 16 and 24 hours. Colour changes were measured in the CIELCh colour system and phenolies were characterized and quantified by means of HPLC. Steaming mainly resulted in a darkening of wood tissues. Colour changes increased as temperature increased from 75 to 125°C. Lightness L * gradually decreased from 0 to 24 h at 75°C. whereas with higher temperatures, most of the darkening occurred within the first 4 hours of exposure. Contrast in colour, between sapwood and heartwood in particular, could he reduced by steaming at 125°C. The best steaming treatment, leading to a colour of steamed sapwood close to that of natural heartwood, was at 100°C/16 h. Hydrojuglone glucoside (HJG), ellagic and gallic acid derivatives (E1, E2 and G respectively) were gradually degraded by steaming, whereas a new flavonol (F) and oxidation products (OP) increased. Relationships between wood colour and phenolic content are discussed.
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the effect of sucrose on the development of hybrid walnut microcuttings Juglans nigra x Juglans regia consequences on their survival during acclimatization
Annals of Forest Science, 1995Co-Authors: D Chenevard, Christian Jayallemand, M Gendraud, J S FrossardAbstract:Nous avons etudie l'effet de la concentration en saccharose dans le milieu de developpement racinaire sur la formation de racines adventives et la survie de 2 clones d'hybrides interspecifiques de noyer (Juglans nigra n° 23 × Juglans regia). Les experiences montrent que l'enracinement necessite la presence de saccharose dans le milieu. Le saccharose augmente a la fois le taux d'enracinement, le nombre de racines adventives et la quantite de matiere seche par pousse enracinee. Cet effet du saccharose est a relier a ses proprietes energetiques plus qu'a son role osmotique. Les concentrations elevees en saccharose dans le milieu de developpement (>20 g.l -1 ) induisent aussi une teneur elevee en sucres solubles dans les pousses enracinees, essentiellement des racines et du cal. Les 2 clones montrent des differences d'enracinement et de croissance. La concentration en saccharose dans le milieu de developpement n'a pas d'effet sur la survie des microboutures pendant la phase d'acclimatation. La survie des pousses enracinees des 2 clones augmente avec le nombre de racines adventives et avec le nombre de feuilles etalees presentes au moment de la phase de transfert en chambre climatisee
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orthophosphate nutrition of in vitro propagated hybrid walnut Juglans nigra x Juglans regia trees pi 32pi uptake and transport in relation to callus and shoot development
Plant Physiology and Biochemistry, 1992Co-Authors: E Barbas, Sylvain Chaillou, Patrick Doumas, Christian Jayallemand, Thierry LamazeAbstract:Orthophosphate nutrition of in vitro propagated hybrid walnut (Juglans nigra x Juglans regia) trees : Pi (32Pi) uptake and transport in relation to callus and shoot development
Paula M Pijut - One of the best experts on this subject based on the ideXlab platform.
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localized gene expression changes during adventitious root formation in black walnut Juglans nigra l
Tree Physiology, 2018Co-Authors: Micah E Stevens, Keith Woeste, Paula M PijutAbstract:Cutting propagation plays a large role in the forestry and horticulture industries where superior genotypes need to be clonally multiplied. Integral to this process is the ability of cuttings to form adventitious roots. Recalcitrance to adventitious root development is a serious hurdle for many woody plant propagation systems including black walnut (Juglans nigra L.), an economically valuable species. The inability of black walnut to reliably form adventitious roots limits propagation of superior genotypes. Adventitious roots originate from different locations, and root induction is controlled by many environmental and endogenous factors. At the molecular level, however, the regulation of adventitious root formation is still poorly understood. In order to elucidate the transcriptional changes during adventitious root development in black walnut, we used quantitative real-time polymerase chain reaction to measure the expression of nine key genes regulating root formation in other species. Using our previously developed spatially explicit timeline of adventitious root development in black walnut softwood cuttings, we optimized a laser capture microdissection protocol to isolate RNA from cortical, phloem fiber and phloem parenchyma cells throughout adventitious root formation. Laser capture microdissection permitted high-resolution, site-specific analysis of gene expression that differentiated between participatory and non-participatory root progenitor cells. Results indicated mRNA abundance was altered in all nine rooting-related genes in response to auxin treatment in both juvenile and mature cuttings. SCARECROW LIKE-1 (SCL) had the greatest change in expression in juvenile rooting-competent cells at days 16 and 18, with a 24- and 23-fold increase relative to day 0, respectively. Tissues not linked to root organogenesis had little change in SCL expression at similar time points. AUXIN RESPONSE FACTOR (ARF)6 and ARF8 as well as SHORTROOT expression also increased 2- to 4-fold in rooting-competent tissue. The greatest transcript abundance in rooting-competent cuttings was restricted to root progenitor cells, while recalcitrant cuttings had a diffuse mRNA signal among tissue types.
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rapid in vitro shoot multiplication of the recalcitrant species Juglans nigra l
In Vitro Cellular & Developmental Biology – Plant, 2018Co-Authors: Micah E Stevens, Paula M PijutAbstract:Black walnut (Juglans nigra L.) has long been prized for its timber, leading to commercial cultivation and significant breeding efforts for improving marketable traits. Vegetative and in vitro black walnut propagation techniques, however, are variable and highly genotype dependent. Optimizing plant growth regulator type and concentration are integral for developing a successful micropropagation protocol. The addition of meta-topolin (MT) combined with the novel use of a liquid medium has led to the development of a rapid shoot multiplication system. The objective of this research was to develop a reproducible and dependable micropropagation protocol for elite black walnut genotypes. In vitro shoot cultures were established from nodal explants cultured on semi-solid Driver and Kuniyuki walnut (DKW) medium supplemented with 8.9 μM benzyladenine, 0.005 μM indole-3-butyric acid (IBA), 200 mg L−1 casein hydrolysate, 50 mg L−1 adenine hemisulfate, 2 mL L−1 Plant Preservative Mixture™, and 4.1 μM MT. Long-term survival and proliferation of microshoots was achieved when nodal segments of in vitro grown shoots were cultured in liquid initiation medium in 3-L polycarbonate Fernbach-style flasks on a rotary shaker (100 rpm) under a 16-h photoperiod at 25°C. Elongated microshoots (5–7 cm in length) were rooted in a slurry-like medium composed of half-strength DKW medium with 0.11% (w/v) Phytagel™ and coarse vermiculite (2:1, v/v) supplemented with 50 μM IBA for 5 wk. Rooted shoots were acclimatized to ambient culture room conditions, but plantlets did not survive once transferred to the greenhouse.
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origin of adventitious roots in black walnut Juglans nigra softwood cuttings rooted under optimized conditions in a fog chamber
New Forests, 2017Co-Authors: Micah E Stevens, Paula M PijutAbstract:High-quality black walnut (Juglans nigra L.) logs are of great economic value and are used in the manufacture of high-end products. Indigenous to the central hardwood region, black walnut has been commercially cultivated for many years, and genetic improvement and selections have resulted in superior timber genotypes. The recalcitrance of black walnut cuttings to form adventitious roots is the greatest hurdle for mass propagation of improved material. The goal of this research was to improve the frequency of adventitious root formation in black walnut cuttings, and investigate anatomical changes during root development. Softwood cuttings (15–20 cm) were collected from juvenile and mature sources of elite genotypes, dipped for 60 s in 31.1, 62.2, or 93.2 mM indole-3-butyric acid-potassium salt (K-IBA), or 36.9, 73.8, or 110.7 mM indole-3-butyric acid (IBA), and then inserted into a moist medium consisting of 3 perlite: 1 coarse vermiculite (v/v). Cuttings were placed in bench-top fog chambers or a mist bench for 5 weeks. To visualize anatomical changes during root formation, stems were fixed in formaldehyde, embedded in paraffin, serially sectioned, and stained on sequential days throughout root development. Rooting was greatest (72%) for cuttings exposed to 93.2 mM K-IBA and placed in the fog chamber, while cuttings treated with IBA rooted at lower frequencies (16–22.2%). Cuttings in the mist bench often deteriorated and rooted at lower frequencies independent of the auxin type. Anatomical analysis revealed adventitious root initials by day 16 and root primordia formation by day 18. Rooted cuttings survived acclimatization to the greenhouse.
Matthew D Ginzel - One of the best experts on this subject based on the ideXlab platform.
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first report of geosmithia morbida on ambrosia beetles emerged from thousand cankers diseased Juglans nigra in ohio
Plant Disease, 2016Co-Authors: Jennifer Juzwik, Margaret Mcdermottkubeczko, T J Stewart, Matthew D GinzelAbstract:Eastern black walnut (Juglans nigra) is a highly-valued species for timber and nut production in the eastern United States. Thousand cankers disease (TCD), caused by the interaction of the walnut twig beetle (Pityophthorus juglandis) and the canker fungus Geosmithia morbida (Tisserat et al. 2009), was first found in the eastern United States in 2010 and is a threat to the health of black walnut in its native range. The recent detection of G. morbida on a weevil species (Stenomimus pallidus) (Juzwik et al. 2015) led to an effort to determine the extent to which beetles other than P. juglandis acquire the fungus on their bodies from TCD-symptomatic trees.
