Dayton Wilde

University of Georgia | UGA · Department of Horticulture

With the rising demand for new cultivars of carnation, efficient transformation protocols are needed to enable the bioengineering of new traits. Here, we established a novel and efficient Agrobacterium-mediated transformation system using callus as the target explant for four commercial carnation cultivars. Leaf-derived calli of all cultivars were...

With the rising demand for new cultivars of carnation, efficient transformation protocols are needed to enable the bioengineering of new traits. Here, we established a novel and efficient Agrobacterium -mediated transformation system using callus as the target explant for four commercial carnation cultivars. Leaf-derived calli of all cultivars were...

Rhododendron canescens (Michaux) Sweet is a deciduous azalea from the southeastern United States that is used as an ornamental landscaping plant. We identified and characterized allelic variation in R. canescens architecture genes as the first step towards breeding a more compact phenotype for urban settings. The transcriptome of R. canescens veget...

A lethal combination Although many human activities have clear negative effects on the natural world, there are also unforeseen consequences. Bald eagle mass death events in the southeastern United States may be one such downstream effect of human activity. After considerable effort, Breinlinger et al. identified the cause of these events as an ins...

Stewartia is a genus of flowering shrubs and trees in the family Theaceae. Stewartia species are native to eastern Asia, with the exception of S. ovata and S. malacodendron, which are indigenous to southeastern North America. Despite having outstanding ornamental value and unique horticultural features, Stewartias are not readily available for land...

Franklinia alatamaha is a small tree in the tea family (Theaceae) that has been valued for its ornamental qualities since 1765, when it was first recorded by John and William Bartram on the Georgia Coastal Plain. The only known population of F. alatamaha became extinct in the wild by the early 1800s. However, F. alatamaha has been cultivated as an...

Franklinia is a monotypic genus of the family Theaceae that is now extinct in the wild. F. alatamaha Bartram ex Marshall has been maintained in cultivation for nearly 250-y because of the ornamental appeal of its flowers and foliage. The goal of this research was to develop an in vitro propagation system to increase the availability of this rare tr...

Eremurus species, better known as ‘Foxtail Lily’ or ‘Desert Candle’, are important worldwide in landscaping and the cut-flower industry. One of the centers of highest diversity of the genus Eremurus is Iran, which has seven species. However, little is known about the genetic diversity within the genus Eremurus. With the advent of genotyping-by-sequ...

Rhododendron canescens is a deciduous azalea native to the southeastern United States that is used in landscaping due to its ornamental qualities. A genotyping-by-sequencing (GBS) approach was taken to characterize the genetic structure and diversity of a R. canescens germplasm collection. Single nucleotide polymorphisms (SNPs) were identified by t...

Somatic embryogenesis in flowering dogwood (Cornus florida) has been achieved, but not the regeneration of plants with active shoot growth. To improve plant regeneration, eight media treatments were tested for induction of somatic embryogenesis from immature zygotic embryos. Somatic embryogenesis was obtained on three media containing the plant gro...

Eight candidate housekeeping genes were examined as internal controls for normalizing expression analysis of durum wheat (Triticum durum L.) under drought and salinity stress conditions. Quantitative real-time PCR was used to analyze gene expression of multiple stress levels, plant ages (24 and 50 days-old), and plant tissues (leaf and root). The a...

Eight candidate housekeeping genes were examined as internal controls for normalizing expression analysis of durum wheat (Triticum durum L.) under drought and salinity stress conditions. Quantitative real-time PCR was used to analyze gene expression of multiple stress levels, plant ages (24 and 50 days-old), and plant tissues (leaf and root). The a...

A blueberry ( Vaccinium sp.) germplasm collection was screened for allelic variation in TERMINAL FLOWER 1 ( TFL1 ) that could be used in breeding flowering or architecture traits. TFL1 has been found to repress the transition from vegetative to reproductive growth in diverse plant species, with mutations leading to altered flowering and form. The V...

Hybrid petunia cultivars are susceptible to infection by powdery mildew (Oidium longipes) and potyviruses (potato Y virus, petunia flower mottle virus) during commercial vegetative propagation. Plant proteins encoded by susceptibility genes are required by powdery mildew and potyviruses to infect plant hosts. To examine the potential of developing...

Exotic plants dominate esthetically-managed landscapes, which cover 30–40 million hectares in the United States alone. Recent ecological studies have found that landscaping with exotic plant species can reduce biodiversity on multiple trophic levels. To support biodiversity in urbanized areas, the increased use of native landscaping plants has been...

Many important traits for plant domestication and improvement have resulted from human selection for novel alleles of structural or regulatory genes. In addition to naturally-occurring genetic mutations, novel alleles have been induced in plants by chemical and physical mutagenesis. The goal of mutagenesis is to induce genetic variation in cells th...

A Petunia hybrida mutant that self-pollinates was identified in an M1 generation of plants mutagenized with ethyl methanesulfonate. A change in floral morphology of the self-pollinating (SP) mutant resulted in flowers with the stigma and anthers in direct contact. Other phenotypic changes in the SP line, which are maintained in M2 and M3 progeny, i...

Research into the taxonomy of a novel cyanobacterial epiphyte in locations where birds, most notably Bald eagle and Ameri-can coots, are dying from a neurologic disease (Avian Vacuolar Myelinopathy—AVM) has been ongoing since 2001. Field investigations revealed that all sites where birds were dying had extensive invasive aquatic vegetation with den...

Several genes are known to play major roles in controlling architectural and flowering traits of ornamental value. We are interested in screening germplasm collections to find allelic variation in these genes that could be used for breeding. Our long-term goal is to develop native plants with ornamental traits through an ecotilling approach with sp...

The development of a chemically-mutagenized population of Petunia hybrida could enable the identification of novel alleles for crop improvement. Conditions were determined for mutagenizing petunia with ethyl methanesulfonate (EMS), while minimizing deleterious effects on viability and fertility. A mutagenized population of the doubled haploid P. hy...

The development of a chemically-mutagenized population of Petunia hybrida could enable the identification of novel alleles for crop improvement. Conditions were determined for mutagenizing petunia with ethyl methanesulfonate (EMS), while minimizing deleterious effects on viability and fertility. A mutagenized population of the doubled haploid P. hy...

To develop genetic resistance to powdery mildew in Petunia hybrida, the mildew locus O gene (Mlo) was identified and characterized. The genomic sequence of petunia Mlo was determined using petunia EST sequences with homology to tomato SlMlo1. A single copy of PhMlo was identified and its expression pattern in petunia was established by RT-PCR. Two...

We investigated the FT/TFL1 family of peach (Prunus persica), a gene family that regulates floral induction in annual and perennial plants. The peach terminal flower 1 gene (PpTFL1) was expressed in a developmental and tissue-specific pattern that, overall, was similar to that of TFL1 orthologs in other woody Rosaceae species. Consistent with a rol...

Mutation breeding can be enhanced by genetic selection for novel alleles. Through targeted mutation breeding, genotypes with induced or natural mutations in candidate genes are identified for cultivar development. For most horticultural plants, targeted mutation breeding may be a more economically feasible approach to trait development than through...

Mutation breeding can be enhanced by genetic selection for novel alleles. Through targeted mutation breeding, genotypes with induced or natural mutations in candidate genes are identified for cultivar development. For most horticultural plants, targeted mutation breeding may be a more economically feasible approach to trait development than through...

Individual HRM analysis of 36 peach cultivars. PCR products spanning PpTFL1 exons 3 and 4 were amplified in separate reactions for each cultivar and analyzed by HRM. Cultivars 16, 28, and 29 demonstrated altered melting patterns when HRM was repeated, but cultivar 21 did not.

PCR primers for amplification of PpTFL1 and PpAG exons.

Peach cultivars analyzed.

PpTFL1 exon 4 sequence. PCR products spanning PpTFL1 exons 3 and 4 were sequenced from 9 peach cultivars. Only the sequence flanking the polymorphic site (arrow) in exon 4 is shown; the remaining sequence was identical. PCR products from cultivars 16 and 29 were also subcloned before sequencing, allowing SNP-containing alleles to be identified.

HRM analysis of PpAG exons 4 + 5. Cultivar 30 was examined in pools of six (Y4), twelve (Y4 + Y5), and eighteen (Y4 + Y5 + Y6) lines. A relative difference plot of melting profiles of a 348 bp amplicon spanning PpAG exons 4 and 5 is shown. Group designations refer to pooling strategy shown in Figure 2A. HRM analysis was performed in triplicate and...

Mutation scanning technology has been used to develop crop species with improved traits. Modifications that improve screening throughput and sensitivity would facilitate the targeted mutation breeding of crops. Technical innovations for high-resolution melting (HRM) analysis are enabling the clinic-based screening for human disease gene polymorphis...

The TERMINAL FLOWER 1 (TFL1) plays crucial roles in regulating the vegetative to reproductive phase transition and maintaining the inflorescence meristem. We characterized one apricot (Pa_GBa141J23) and one peach (Pp_NBa103A15) BAC clone harboring a TFL1 gene. Sequence analysis revealed that the apricot and peach TFL1 (PaTFL1 and PpTFL1) genes disp...

The productivity of plantation forests is essential to meet the future world demand for wood and wood products in a sustainable fashion and in a manner that preserves natural stands and biodiversity. Plantation forestry has enormously benefited from development and implementation of improved silvicultural and forest management practices during the...

Peanut (Arachis hypogaea L.) lines transgenic for the antisense nucleocapsid (N) gene of a Tomato spotted wilt virus (TSWV) strain isolated from peanut were generated by microprojectile-mediated transformation of repetitive somatic embryos of cultivars VC1 and AT120. The selectable marker (hygromycin resistance) and the N gene were on separate plas...

Embryogenic cultures of soybean [Glycine max (L.) Merr. cv. Jack and Asgrow A2872] were established in liquid Finer and Nagasawa medium, maintained by transfer to fresh medium at biweekly intervals, and subjected to microprojectile bombardment over time. Cultures were not amenable to transformation until they were at least 6 months old. Over time,...

With global heavy metal contamination increasing, plants that can process heavy metals might provide efficient and ecologically sound approaches to sequestration and removal. Mercuric ion reductase, MerA, converts toxic Hg2+ to the less toxic, relatively inert metallic mercury (Hg0) The bacterial merA sequence is rich in CpG dinucleotides and has a...

The developmental biology of somatic embryos is similar in many respects to that of plant zygotic embryos. For that reason, the analysis of gene expression during somatic embryogenesis has been viewed as an alternative means to investigate the genetic control of zygotic embryo development, which can be technically difficult. In the study of gene ex...

The family Magnoliaceae contains an number of trees valued for both horticultural and forestry purposes. Some species, particularly in the genus Magnolia, are quite rare, and vegetative propagation by conventional means has been difficult. We have developed embryogenic regeneration systems for a number of rare Magnolia species, such as M. cordata a...

Liriodendron tulipifera L. (yellow poplar) is one of the most common hardwood forest species in eastern North America, growing throughout the eastern United States and into southern Ontario, Canada. The species is most abundant and reaches its largest size in the lower Ohio River valley and in the Appalachian mountains of North Carolina, Tennessee,...

Liriodendron tulipifera L. (yellow-poplar, tulip-poplar, tuliptree), a native of eastern North American, is one of two extant species of Liriodendron (Magnoliaceae). The other, L. chinense (Hemsl.) Sarg. (Chinese tuliptree), is native to central mainland China. The natural range of yellow-poplar is throughout the eastern United States and into sout...

Somatic proembryos of mango (Mangifera indica L. cv. Hindi) were co-cultivated withAgrobacterium tumefaciens strain A208 harboring pTiT37-Se::pMON 9749 (9749 ASE). Transformed somatic proembryos capable of growing on selection medium containing 200 μg/ml kanamycin produced the characteristic indigo blue precipitate in the presence of 5-bromo-4-chlo...

Cells of yellow-poplar (Liriodendron tulipifera L.) were transformed by direct gene transfer and regenerated into plants by somatic embryogenesis. Plasmid DNA bearing marker genes encoding beta-glucuronidase (GUS) and neomycin phosphotransferase (NPT II) were introduced by microprojectile bombardment into single cells and small cell clusters isolat...

Yellow-poplar can be regenerated from tissue culture by somatic embryogenesis. The transformation of embryogenic cultures should allow the production of transgenic yellow-poplar plants. Direct gene transfer methods have been used to introduce the gene encoding ß-glucuronidase (GUS) into protoplasts (polyethyene-glycol mediated uptake, electroporati...

Extensive studies of gene expression programs in carrot somatic embryos identified a gene, designated Dc3, that serves as a reliable molecular marker for the acquisition of embryogenic potential by carrot cells in culture. The complete sequence of a carrot genomic region, DcG3, encoding a Dc3-like mRNA, was determined. The DcG3 transcription unit c...

Embryogenic suspension cultures of domesticated carrot (Daucus carota L.) are characterized by the presence of proembryogenic masses (PEMs) from which somatic embryos develop under conditions of low cell density in the absence of phytohormones. A culture system, referred to as starting cultures, was developed that allowed analysis of the emergence...

Somatic embryogenesis can be synchronized by enriching carrot (Daucus carota L.) suspension cultures for small, dense clusters of cells termed proembryogenic masses (PEMs). Gene-expression programs of PEMs were compared with those of embryonic and mature tissues by in-vitro translation of representative mRNA populations and by nucleic-acid hybridiz...

Recent advances in instrumentation have lead to an examination of the effect of different measurement techniques on the overall accuracy achievable in energy flow measurement. In particular, past assumptions about gas quality encouraged measurement techniques which can introduce inaccuracies under today's changing conditions. This paper examines so...

Summary The productivity of plantation forests is essential to meet the future world demand for wood and wood products in a sustainable fashion and in a manner that preserves natural stands and biodiversity. Plantation forestry has enormously benefited from development and implementation of improved silvicultural and forest management practices dur...

Cells ofyellow-poplar (Liriodendron tulipifera L.)weretrans- formedbydirect genetransfer andregenerated intoplants by somatic embryogenesis. Plasmid DNA bearing markergenes encoding,8-glucuronidase (GUS) andneomycin phosphotransfer- ase(NPTII) wereintroduced bymicroprojectile bombardment into single cells andsmall cell clusters isolated fromembryog...