Search

The article focuses on two low-growing cultivars of black chokeberry, 'UCONNAM012' (Ground HugVR) and 'UCONNAM165' (Low Scape MoundVR), highlighting their landscape adaptability and breeding origins. Topics include the characteristics, landscape use, and clonal propagation methods of these cultivars, emphasizing their potential as ornamental shrubs with multiseason interest and ecological benefits.

This document provides information about a specific cultivar of black chokeberry called 'UCONNAM166'. It is a non-rhizomatous shrub with upright growth and compact form, and it does not produce fruit. The plant is well-suited for full sun or partial shade conditions and can tolerate challenging landscape situations, such as dry soils. It has ornamental features throughout the year, including white flowers in May, shiny green leaves in summer, and colorful fall foliage. The cultivar is mostly sterile and unlikely to establish in native habitats. The document also provides information on the clonal propagation and availability of the cultivar. [Extracted from the article]

The article reports that Berberis thunbergii L. (Japanese barberry) holds significant market share in the commercial ornamental horticulture industry. Japanese barberry is grown by production nurseries and used in landscaping across the northern half of the U.S. It mentions that Japanese barberry's popularity as a commercial horticulture staple crop has also resulted from its ease of culture under production nursery conditions.

New Jersey tea (Ceanothus americanus L. [Rhamnaceae]), sand cherry (Prunus pumila L. [Rosaceae]), and sweetbells (Eubotrys racemosa L. [Ericaceae]) are eastern US native shrubs with high potential for expanded landscape use because of their numerous ornamental attributes and adaptability. Micropropagation protocols were developed for these species that produce acceptable shoot multiplication rates, 100% microcutting rooting, and high-quality liner plants. New Jersey tea is not easily produced from seed or stem cuttings for commercial purposes, but we have demonstrated that micropropagation is a viable method for commercial propagation. In addition, micropropagation can be effectively used to rapidly propagate new superior genotypes of sand cherry and sweetbells. [ABSTRACT FROM AUTHOR]

Intergeneric hybridization between Aronia and Pyrus may provide a pathway for developing novel fruit types with larger, sweeter fruits, while maintaining the high levels of biologically health-promoting compounds present in Aronia fruits. Here we describe a deleterious genetic incompatibility, known as hybrid necrosis or hybrid lethality, that occurs in intergeneric F1 hybrids of Aronia melanocarpa x Pyrus communis and 3Sorbaronia dippelii x Pyrus communis. Pollination experiments revealed that maternal A. melanocarpa and 3S. dippelii pistils are compatible with pollen from P. communis. Controlled pollinations using different mating combinations resulted in varying levels of fruit and seed set. Because every combination produced at least some viable seeds, prezygotic incompatibility does not appear to be present. We attempted to recover putative intergeneric progeny via either in vitro germination or in vitro shoot organogenesis from cotyledons. Progeny of putative hybrids from A. melanocarpa x P. communis only survived for a maximum of 14 days before succumbing to hybrid lethality. Regeneration of 3S. dippelii x P. communis was successful for two seedlings that have been maintained for an extended time in tissue culture. These two seedlings have leaf morphologies intermediate between the two parental genotypes. We also confirmed their hybrid status by using AFLPs and flow cytometry. Putative intergeneric hybrids were grown out ex vitro before showing symptoms of hybrid necrosis and dying after 3 months. Eventually micrografts failed, ultimately showing the same symptoms of hybrid necrosis. These results show that intergeneric hybridization is possible between Aronia and related genera in the Rosaceae, but there are postzygotic barriers to hybridity that can prevent the normal growth and development of the progeny. [ABSTRACT FROM AUTHOR]

To maximize yield, cannabidiol (CBD) hemp producers prefer female plants, and this is accomplished by using expensive feminized seed, vegetatively propagated female clones, or by removing male plants from dioecious seed lots. Hemp pollen drifts long distances on wind, and pollination of females reduces CBD content. Induction of triploidy is a common strategy used by plant breeders to produce sterile cultivars of agricultural crops. Triploid (3n) hemp, with three sets of chromosomes, was developed by crossing naturally diploid (2n) hemp with tetraploid (4n) hemp. Tetraploid plants used to create triploids were produced using pregerminated seeds and the mitotic spindle inhibitor colchicine. Seedlings from seeds of 'Abacas' 3 [('Otto2' 3 'BaOx') 3 ('BaOx' 3 'Colorado Cherry')] treated with 0.05% colchicine or 0.02% colchicine for 12 hours and longer were significantly shorter than controls and £1 cmtall at 10 days after sowing. Surviving seedlings exhibited thickened cotyledons and hypocotyls, which indicated a potential change in ploidy. Tetraploid induction ranged from 26% to 64% for pregerminated seeds of five different hemp cultivars (Abacus 3 Wife, Cherry Wine, Mountain Mango, Wife, and Youngsim10) treated with 0.05% colchicine for 12 hours. Tetraploids had nearly twice the DNA content as diploids according to flow cytometric analysis. Tetraploid 'Wife' had larger stomates and reduced stomatal density compared with diploid 'Wife'. Four triploid 'Wife' genotypes produced from crossing tetraploid 'Wife' with diploid 'Wife' were acclimated to greenhouse conditions after embryo rescue. DNA content and stomate size of triploid 'Wife' was intermediate between the parents. This is the first report of triploid plants of hemp. Future research will evaluate the sterility of triploid hemp. [ABSTRACT FROM AUTHOR]

Northern bayberry [Morella (formerly Myrica) pensylvanica] is an attractive, adaptable, semievergreen, northeastern North American native shrub that is sought for landscaping but difficult to propagate clonally. The impact of timing (June, July, or August) and concentration of indole-3-butyric acid [IBA (0, 2000, 4000 or 8000 ppm)] on propagation by stem cuttings was evaluated for genotypes of northern bayberry including the female cultivars Bobzam (Bobbee™) and UConn Compact and an unnamed male. Medium formulation and cytokinin type were evaluated for micropropagation of ‘Bobzam’ and ‘UConn Compact’. Stem cuttings of ‘Bobzam’ and ‘UConn Compact’ rooted poorly (at ≤55% and ≤20%, respectively) at all timings and concentrations of IBA; however, rooting success of ≥85% was achieved for the unnamed male genotype when cuttings were taken in June. Micropropagation of ‘Bobzam’ was successful using Woody Plant medium with 4 mg·L−1 zeatin and explants taken from shoots that had expanded 12 to 18 cm on containerized stock plants. Initiated explants of ‘Bobzam’ required eight subcultures before they began to produce shoots consistently at a 2× multiplication rate and eventually reached a 3× multiplication rate. Micropropagation attempts using Murashige and Skoog medium, the cytokinins 6-benzylaminopurine, meta-topolin, and thidiazuron, or the cultivar ‘UConn Compact’ were unsuccessful. Microshoots of ‘Bobzam’ rooted at ≥80% either by in vitro prerooting or ex vitro rooting directly in trays. Rooted micro-cuttings easily acclimated to greenhouse conditions and grew rapidly when potted to 1.04-L containers and then into 5.68-L containers. The micropropagation protocol developed for ‘Bobzam’ can be used by propagators to expand production of this popular female cultivar. [ABSTRACT FROM AUTHOR]

Total phenolics, anthocyanins and ORAC FL values from a large number of wild and cultivated genotypes of dark-fruited Aronia melanocarpa (diploid and tetraploid), Aronia prunifolia and Aronia mitschurinii were quantified and characterized in two consecutive years. The A. prunifolia taxonomic group had the highest total phenolic content. The diploid A. melanocarpa group had the highest ORAC FL values and A. mitschurinii the lowest values. Anthocyanin content was highest in the diploid A. melanocarpa group and also in the A. mitschurinii group in 2011. Anthocyanin content was lowest for the A. prunifolia group. Accessions UC009, UC047 and UC082 had elevated amounts of cyanidin-3-galactoside and reduced cyanidin-3-arabinoside, suggesting they have altered anthocyanin metabolism compared to most accessions. Polyphenol content for the same genotypes varied significantly between years, especially for wild germplasm. Wild Aronia genotypes represent a significant source of fruit biochemical diversity and have substantial potential for use directly in nutraceutical fruit production or in plant breeding programs. [ABSTRACT FROM AUTHOR]

This study reports the development, characterization, and cross-species transferability of 20 genomic microsatellite markers for Aronia melanocarpa, an important nutraceutical fruit crop. The markers were developed with Illumina paired-end genomic sequencing technology using DNA from Professor Ed cultivar that was originally collected fromthe wild in NewHampshire. The markers were highly polymorphic and transferable to Aronia arbutifolia and Aronia prunifolia genomes. The average number of alleles per locus was 9.1, 4.5, and 5.6 for A. melanocarpa, A. arbutifolia, and A. prunifolia, respectively. The polymorphism information content (PIC) of loci ranged from 0.38 to 0.95 for all taxa, with an average of 0.80, 0.68, and 0.87 for A. melanocarpa, A. arbutifolia, and A. prunifolia, respectively. This is the first study to develop microsatellite markers in the Aronia genus. These markers will be very useful in studying the genetic diversity and population structure of wild Aronia and expediting the breeding efforts of this emerging fruit crop through marker-assisted selection. [ABSTRACT FROM AUTHOR]

The genus Aronia Medik., also known as chokeberry, is a group of deciduous shrubs in the Rosaceae family, subtribe Malinae. The two commonly accepted black-fruited Aronia species are black chokeberry [Aronia melanocarpa (Michx.) Elliott] and aroniaberry [Aronia mitschurinii (A.K. Skvortsov & Maitul)]. The geographic range of wild A. melanocarpa is the Great Lakes region and the northeastern United States, with a southerly extension into the higher elevations of the Appalachian Mountains. Wild A. melanocarpa found in New England are diploids, whereas plants throughout the rest of the range are tetraploids. A. mitschurinii is a cultivated hybrid between ×Sorbaronia fallax (C.K.Schneid.) C.K.Schneid. and A. melanocarpa and exists as a tetraploid. There is currently limited diversity of Aronia genotypes in the ornamental and fruit industries, and many of the current cultivars are not adapted to the southern United States and similar environs with limited chilling to break winter dormancy. The goal of this study was to determine 1) the chilling requirements for A. mitschurinii 'Viking' and 2) the range of chilling requirements for wild A. melanocarpa genotypes from different geographic origins. Two experiments were conducted in which plants were subjected to various chilling accumulation treatments and then moved to a greenhouse for observation of budbreak and subsequent growth. Expt. 1 was conducted at the University of Maryland at Wye, MD, and focused solely on the commercial cultivar A. mitschurinii 'Viking'. Outdoor, ambient fall and winter temperatures were used to achieve the chilling treatments. In Expt. 1, we determined the optimal chilling requirements for A. mitschurinii 'Viking' to be greater than 900 h using the single temperature model. Expt. 2 was conducted at the University of Connecticut and focused on wild genotypes, plus A. mitschurinii 'Viking'. A fixed temperature cold room was used to achieve chilling treatments. In Expt. 2, we found A. melanocarpa genotypes from southern regions in the United States required chilling accumulation of 600 h (single temperature model), compared with genotypes from northern regions that required more than 900 h of chilling accumulation. Tetraploid A. melanocarpa required 900 h of chilling to break bud, but diploid A. melanocarpa required 1200 h of chilling to break bud. Expt. 2 confirmed the 900-h chilling requirement for A. mitschurinii 'Viking'. For both experiments, the rate of budbreak and shoot growth was positively correlated with increasing amounts of chilling. [ABSTRACT FROM AUTHOR]

Aroniaberry (Aronia mitschurinii) produces small pome fruits that possess health promoting compounds. Management practices for orchards are lacking, since aroniaberry is a relatively new crop. Pruning is an important cultural practice to optimize fruit yield in orchards. The response of an established aroniaberry orchard to pruning was evaluated over three years (2020 to 2022). Pruning treatments were as follows: 1) renewal pruning (removal of shoots to the base) only in year 1; 2) renewal pruning in year 1 + thinning to 18 shoots in year 2; 3) renewal pruning in year 1 + thinning to 9 shoots in year 2; and 4) no-pruning (control). In response to renewal pruning, plants grew uniformly and vigorously, producing 28 new vegetative primary shoots with an average length of 66 cm by the end of the first growing season. Limited flowering and fruiting occurred in the second season for plants receiving pruning treatments. Fruit yield on pruned plants was significantly less than for unpruned controls. In season 2, increased thinning of renewal-pruned plants negatively affected the number of inflorescences per plant, but positively affected individual fruit fresh weight and fruit °Brix:titratable acidity ratios. Fruits from all treatments had similar monomeric anthocyanins, total phenolics and mineral content. In season 3, flower production and predicted fruit yield from pruned plants and unpruned controls were similar, even though pruned plants were substantially smaller. In the third season, there were no longer any differences between renewed + thinned plants and those that received only renewal pruning, making shoot thinning an unnecessary practice. The results of this study demonstrate that renewal pruning can be an effective way to manage and rejuvenate an aging aroniaberry orchard. [ABSTRACT FROM AUTHOR]

The article focuses on purpleleaf sandcherry, Prunus and cistena, was first released in 1910 by N.E. Hansen at the South Dakota Agricultural Research Station (Jacobson, 1992). Topics include the hybrid was the result of a cross between Prunus pumila var. besseyi, a cold hardy shrub of North America, and Prunus cerasifera var. atropurpurea, and the hybrid appears to be mostly sterile, but can produce occasional small, and dark-purple to black fruit.

The article offers information about the Prunus pumila (L.), sandcherry, a native North American small shrub. It mentions about the ‘UCONNPP002' sandcherry is a new cultivar of the North American woody native species Prunus pumila. It discusses that U.S. plant patent application has been submitted and accepted by the U.S. Office of Patents and Trademarks for Prunus pumila ‘UCONNPP002'.

Tissue proliferation (TP) is characterized primarily by the formation of galls or tumors at the crown of container-grown rhododendrons that were initially propagated in vitro. In the cultivar 'Montego', TP-like symptoms are first observed in vitro as shoot clusters with small leaves and nodal tumors. In addition, unlike the normal in vitro non-TP (TP-) shoots, in vitro TP (TP+) shoots proliferate rapidly without the presence of the plant growth regulator cytokinin in the tissue culture medium. Comparisons of the anatomy of TP(+) and TP(-) shoot tips showed that TP(+) shoots had a less developed vascular system and altered internodal elongation at the shoot apex. In addition, TP(+) axillary buds were abnormal in that they were displaced onto the stem above the leaf axil, and a small group of proliferating cells replaced the shell zone at the base of the bud. Initiation of tumor formation began with the expansion of this region of cell proliferation (RCP) and shoot growth from the abnormal axillary bud (tumor bud). Organization of the tumor bud characterized two patterns of further tumor development. In polar shoot tumors, shoot growth continued from the persistent tumor bud and the tumor at base of the shoot remained small in size. In non-polar tumors, the tumor bud became dedifferentiated and de novo meristem formation led to the formation of large tumors with or without shoots. The RCP was a common feature in polar shoot tumors and in non-polar tumors.

• AFLP analysis and ploidy were used to evaluate 132 accessions of Aronia. • Aronia was found to be comprised of four, or possibly five, species and seven taxonomic groups. • arbutifolia was tetraploid, and A. prunifolia was typically tetraploid, and rarely triploid. • Diploid A. melanocarpa were found in New England, but elsewhere they were tetraploid. • Formation of A. prunifolia as a hybrid of A. arbutifolia by A. melanocarpa is supported by AFLP analysis and ploidy. Speciation in Aronia is complex based on Amplified Fragment Length Polymorphism (AFLP) and ploidy analysis of 132, mostly wild, accessions. There are four species of Aronia and seven taxonomic groups comprised of species by ploidy combinations. A. melanocarpa can be diploid or tetraploid, with diploid forms occurring in New England and tetraploid forms occurring primarily outside of New England. A. arbutifolia was only found as a tetraploid and did not appear to occur throughout parts of New England as is generally accepted. It is likely that numerous misidentifications of A. arbutifolia have occurred historically. Almost all wild A. prunifolia were tetraploid, with the exception of a single triploid plant. Evidence from AFLP analysis and several accessions expressing a continuum of morphological characteristics between those of A. arbutifolia and A. melanocarpa suggest that A. prunifolia is of interspecific hybrid origin. The occurrence of a natural triploid A. prunifolia accession and our ability to easily create triploid A. prunifolia progeny from diploid A. melanocarpa by tetraploid A. arbutifolia crosses supports the hybrid formation of the A. prunifolia species. Hybrid A. prunifolia origin is also supported by the prevalence of A. prunifolia accessions in geographic areas where A. arbutifolia and diploid A. melanocarpa interface. Most likely, tetraploid A. prunifolia found in the wild result from repeated formation of triploid F 1 interspecific hybrids and the triploid bridge mechanism. AFLP analysis, along with morphology and phenology, suggest that a new species of black-fruited Aronia (melanocarpa S) exists in the southern part of the A. melanocarpa geographic range. A. melanocarpa S plants are placed on a separate branch of the AFLP dendrogram that is separate from other Aronia species. Several accessions with large, wide leaves, large fruits and non-rhizomatous growth were found to be A. mitschurinii , an intergeneric hybrid between Aronia and Sorbus. All A. mitschurinii accessions were tetraploid. [ABSTRACT FROM AUTHOR]

The article offers information on Comptonia peregrina, is a species of flowering plant in the family Myricaceaeis typically 60 to 120 cm tall and produces leaves that are 5 to 12 cm long and 1.2 to 2.5 cm wide (Dirr, 2011).

Aronia Medik., commonly known as chokeberry, is a genus of deciduous, multistemmed, rosaceous shrubs native to eastern North America. Three species of chokeberry are commonly accepted, A. arbutifolia (L.) Pers., red chokeberry, A. melanocarpa (Michx.) Elliott, black chokeberry, and A. prunifolia (Marshall) Rehder, or purple chokeberry. In Europe, a fourth species of human origin is recognized us Aronia mitschurinii A.K.Skvortsov & Maitul. In North America this type of Aronia is described as cultivars of A. melanocarpa, including 'Viking', 'Nero', and 'Aron'. This species is characterized by near homogeneity of the population, tetraploidy, and a distinct morphology with more robust stems, wider leaf blades, and larger fruits than wild populations of A. melanocarpa. It has been proposed that this genotype originated from Russian pomologist Ivan Michurin's early 20th century experiments involving Aronia x Sorbus hybridization. In this study we used amplified fragment length polymorphic (AFLP) markers to elucidate the relationships of A. mitschurinii to wild North American Aronia, x Sorbaronia C.K. Schneid, Sorbus L., and six additional genera from subtribe Pyrinae (Rosaceae). Data from seven primer combinations were interpreted by the NTSYSpc software package into a similarity matrix using Jaccard's coefficient. Clustering of AFLP similarity data using the unweighted pair group method with arithmetic mean (UPGMA) identified A. mitschurinii as distinct from wild Aronia, grouping it close to x Sorbaronia fallax C. K. Schneid. and x Sorbaronia 'Ivan's Beauty'. Non-metric multidimensional scaling (nMDS) also demonstrated a relationship between A. mitschurinii, x Sorbaronia fallax, a x Sorbaronia x Aronia backcross and compound-leaved Sorbus. [ABSTRACT FROM AUTHOR]

Berberis Xottawensis is the hybrid of B. vulgaris (common barberry) and B. thunbergii (Japanese barberry). In the wild, this interspecific taxon appears to have been largely overlooked. Here, we report that this hybrid is relatively widespread in Connecticut and Massachusetts. Furthermore, we present evidence that the hybrid individuals are capable of producing some viable seed and pollen. [ABSTRACT FROM AUTHOR]

Japanese barberry (Berberis thunbergii DC.) is a popular ornamental shrub used in garden and urban landscaping. Currently there are over 60 B. thunbergii cultivars in the market. To better distinguish its cultivars, we used the amplified fragment length polymorphism (AFLP) technique to develop DNA marker profiles for 59 cultivars and hybrids. These markers were used to authenticate the trueness-to-name of B. thunbergii cultivars in production and in the market, control for intracultivar genetic variants, and develop a molecular key to identify cultivars approved for importation in Canada. Polymorphic markers from seven primer combinations were able to clearly differentiate 57 of 59 cultivars evaluated. Two cultivars, Aurea and Aurea Nana, could not be differentiated because they had identical marker profiles. Among the 274 plants tested, 263 were confirmed to be true-to-name and correctly labeled, whereas 11 plants could not be confirmed true-to-name. Seven of the 20 cultivars evaluated exhibited detectable intracultivar genetic variation. 'Crimson Pygmy' had the highest number of plants exhibiting genetic variability. Overall, nursery producers and retailers do not appear to be mixing or mislabeling cultivars. A molecular key developed from a subset of 25 markers was able to accurately identify and differentiate the 11 B. thunbergii cultivars approved for importation in Canada. This key could be used in a cultivar verification program to facilitate international trade of B. thunbergii cultivars where wheat rust is a concern. [ABSTRACT FROM AUTHOR]

Winged euonymus [Euonymus alatus (Thunb.)] is an important landscape shrub that has demonstrated its potential to be invasive in numerous states across the central and northern United States. Nine cultivars were evaluated for their potential to produce fruits and seeds in a randomized, replicated field planting. Seeds from all cultivars were evaluated for germination rate and initial survival in a deciduous woodland. Seeds collected from 'Compactus' were also sown in five natural environments (full sun meadow, edge of woods, moist woods, dry woods, pine woods) to determine which habitat types support its germination and establishment. Seed production for cultivars varied from 981 to 6090 seeds per plant. The dry deciduous woods and pine woods were the only environments that supported significant germination rates that could be as high as 37.8%. Seedling survival was at least 77% in the deciduous dry woods and at least 55% in the pine woods. In the first replication, establishment rates for cultivars in the dry deciduous woods ranged from a low of 6.5% for 'Odom' Little Moses™ to a high of 42.5% for 'Monstrosus'. In the second replication, all cultivars achieved over 30% establishment and most exceeded 40% establishment. An estimate of the annual seedling contribution per plant per cultivar was calculated by combining seed production data with establishment data for each cultivar. This estimate was predicted to range from 588 to 3763 and therefore none of the nine cultivars evaluated should be considered non-invasive based on our findings. Our findings show that germination and seedling survival rates are high for E. alatus and because the species is long-lived, cultivars will likely have to be completely seed-sterile to be considered non-invasive according to demographic models. [ABSTRACT FROM AUTHOR]

We investigated the role of an ornamental, purple-leaved specimen of Japanese barberry in a local invasion using parentage analysis. We focused on a landscape plant of B. thunbergii var. atropurpurea in Willington, CT, that was first established at least 30 years ago. We genotyped every barberry plant found within a 92-m radius of this individual, in contrast to feral populations that are distant from residential or commercial plantings, 14% of the 43 feral plants in our sample had purple foliage and 30% were found growing within 16.5 m of the focal individual. Parentage analysis identified seven plants (five purple-leaved and two green-leaved) as descendants of the focal individual. Five of these descendants are likely first-generation offspring and two are likely second-generation seedlings, in addition, one plant was identified as a backcross between the focal plant and one of its offspring. Our results show that purple-leaved Japanese barberry used in residential landscapes can contribute to plant invasions, at least under some circumstances. [ABSTRACT FROM AUTHOR]

Abstract: Japanese barberry (Berberis thunbergii DC) is an invasive shrub, widely naturalized across the United States, whose numerous cultivars remain an important horticultural commodity. Maintaining this crop for the future necessitates the development of sterile clones. Exposure to the mitotic inhibitors colchicine and oryzalin is a traditional method for inducing tetraploidy in breeding lines as a precursor to creating sterile genotypes. Treatments utilized pre-germinated B. t. var. atropurpurea seeds with emerged radicles. Seeds were immersed in aqueous solutions of colchicine (.02%, .05%, .1% and .2%) and oryzalin (.002%, .005%, .01% and .02%) dissolved in 1% DMSO for 6, 12 and 24h durations. Seedling ploidy level was determined via flow cytometry following 6 and 52 weeks of growth in the greenhouse. Both anti-mitotic chemicals proved effective at inducing tetraploidy and produced comparable efficiency rates. The survival rate of treated seeds decreased in response to both increased mitotic inhibitor concentration and longer exposure duration. While exposure to oryzalin produced greater seed mortality than colchicine, most seedlings that survived had altered ploidy levels. The most efficient oryzalin concentration was 0.002% with a rating of 28%, while the most efficient colchicine concentrations were in the range from 0.05% to 0.2%. Duration of exposure to mitotic inhibitor was not a significant factor over the range from 6 to 24h. Reversion of tetraploid plants to the diploid state occurred at a low frequency following a dormancy period. Some tetraploid seedlings derived from exposure to both chemicals displayed foliar abnormalities including irregular leaf margins and mottled lamina. The primary advantage of colchicine was low seedling toxicity, while oryzalin was notable for its ability to induce tetraploidy at low concentrations. [Copyright &y& Elsevier]

Cultivars of Berberis thunbergii DC. are among the most popular garden shrubs in the United States. Using 174 amplified fragment length polymorphism (AFLP) markers we were able to differentiate between 43 B. thunbergii cultivars and analyse the genetic similarity of 62 B. thunbergii genotypes, B. julianae, B. koreana, B. vulgaris and B. vulgaris 'Atropurpurea'. Seven different accessions of B. thunbergii 'Crimson Pygmy' from a variety of sources had identical AFLP profiles, indicating that there is only one genotype in cultivation and not a collection of similar genotypes. B. thunbergii cultivars 'Crimson Pygmy', 'Crimson Dwarf', and 'Monomb' Cherry Bomb™ could not be distinguished and appeared to be the same genotype. The B. thunbergii cultivars 'Concorde' and 'Criruzam' Crimson Ruby™ are most likely genotypes of B. × ottawensis since they formed a cluster with known B. × ottawensis cultivars. The B. thunbergii var. atropurpurea accessions analysed had Jaccard's coefficients ranging from 0.89 - 0.99 and, therefore, were probably derived from highly inbred seed. A dichotomous identification key was developed for 42 B. thunbergii cultivars and hybrids and B. vulgaris 'Atropurpurea' using 23 markers. This key can be used to ensure that only legal cultivars are sold, if cultivar-specific bans are enacted, and to prevent the importation of rust-susceptible cultivars into Canada. [ABSTRACT FROM AUTHOR]

The leaf color of seedling populations derived from ornamental genotypes of Japanese barberry (Berberis thunbergii DC.) was evaluated to determine whether nursery selections of this important landscape plant could be expected to produce green-leaf progeny or seedlings with leaf color resembling the purple-leaf or yellow-leaf parent. This is a compelling inquiry since nearly all B. thunbergii plants found within invasive populations possess green foliage and the potential contribution of seedlings by ornamental purple- and yellow-leaf genotypes is unknown. Seed lots collected from cultivated barberry genotypes located in landscape settings were processed and raised in a greenhouse to observe leaf color phenotype. It was found that all genotypes studied produced at least some green seedlings. The percentage of green progeny produced varied widely by genotype. Green-leaf cultivars yielded close to 100% green seedlings and all purple- and yellow-leaf forms produced at least 20% green offspring. Among purple-leaf genotype accessions located adjacent to potential purple-leaf pollen donors, var. atropurpurea produced significantly fewer green seedlings (18.5%) than 'Crimson Pygmy' (71%) and 'Rose Glow' (45%). 'Rose Glow' individuals growing adjacent to other purple Japanese barberry forms produced significantly fewer green seedlings (45%) than 'Rose Glow' accessions that were isolated from additional purple Japanese barberry (88%). This study demonstrates that some invasive green-leaf B. thunbergii could be derived from popular garden forms since purple- and yellow-leaf genotypes readily produce green-leaf offspring which resemble feral barberry. These findings do not, however, provide any definitive link between cultivated and naturalized Japanese barberry. [ABSTRACT FROM AUTHOR]

Ornamental plant transformation has advanced considerably in the last decade. Now over 40 genera have been reported to be transformed. The primary methods of creating transgenic ornamental species have been Agrobacterium tumefaciens-mediated transformation and microprojectile bombardment. The vast majority of reports indicate the use of Agrobacterium-mediated transformation employing binary vectors and vir helper plasmids or supervirulence genes. Many reports are of transformation with the uidA reporter gene driven by the 35S cauliflower mosaic virus promoter, but recent efforts are now focusing on trait genes including disease resistance, flower color, flower longevity, floral scent and plant habit. Greater use of tissue specific and inducible promoters promises to enhance the functionality and usefulness of introduced trait genes. While technical challenges for production of transgenic ornamental plants still exist, the greatest challenges to realizing the potential benefits of transgenic ornamental plants are questionable public acceptance of transgenic plants and the prohibitive costs of generating environmental impact data needed to gain regulatory clearance. doi:10.1300/J411v17n01_02 [ABSTRACT FROM PUBLISHER]

While japanese barberry (Berberis thunbergii DC.) is an acknowledged invasive plant naturalized throughout the eastern and northern U.S., the danger posed by its popular horticultural forms is unknown and controversial. This work analyzed the reproductive potential and seedling growth of four ornamental genotypes Important to the nursery industry. Fruit and seed production was quantified In 2001, 2002, and 2003 for multiple landscape plants of B.t. var. atropurpurea, 'Aurea', 'Crimson Pygmy', and 'Rose Glow'. The overage number of seeds produced per landscape specimen ranged from lows of 75 and 90 for 'Aurea' and 'Crimson Pygmy' to 2968 for var. atropurpurea and 762 for 'Rose Glow'. Seed production relative to canopy surface area for 'Rose Glow' was similar to 'Aurea' and 'Crimson Pygmy' and all three cultivars were less prolific than var. atropurpurea in this regard. Cleaned and stratified seeds from var. atropurpurea, 'Crimson Pygmy' and 'Rose Glow' showed an average greenhouse germination rate of 70% to 75%, while 'Aurea' yielded 46% germination. A subpopulation of seedlings from each genotype accession was grown further outdoors in containers for a fag season to ascertain seedling vigor and development. The vigor of 1-year-old seedlings, as measured by dry weight of canopy growth, for progeny derived from 'Aurea' (0.70 g) and 'Crimson Pygmy' (0.93 g) was significantly less than var. atropurpurea (1.20 g) and 'Rose Glow' (1.33 g), These results demonstrate that popular japanese barberry cultivars express disparate reproductive potential that, after further study, may be correlated with invasive potential. Some popular commercial cultivars may pose significantly less ecological risk than others. [ABSTRACT FROM AUTHOR]

Epimedium is a genus of shade tolerant herbaceous perennials and groundcovers that are slow growing and command high prices. This research examined the influence of division size and timing on propagation success and growth of E. pinnatum ssp. colchicum Boiss., E. x rubrum Morren, E. x versicolor 'Sulphureum' Morren and E. x youngianum Fisch. To determine an appropriate division size for each species, small (single bud) and large (three bud) divisions were made in mid-June 2002 and 2003. For the timing study, uniform divisions (three to five buds for E. pinnatum ssp. colchicum and E. x versicolor 'Sulphureum'; four to seven buds for E. x rubrum and E. x youngianum) were made in March, late June and late August, when plants were dormant, had just completed foliage expansion, or were summer dormant. Half of the plants were destructively harvested in the fall and half were overwintered and forced in the greenhouse in early spring. By the end of the growing season, plants grown from large divisions were larger than those grown from small divisions and had produced more buds, however, plants from small divisions produced more buds per initial bud than plants from large divisions, demonstrating a faster increase in growing points. For each species, March divisions produced more vegetative growth, buds, buds per initial bud and potential propagules than June and August divisions, by the end of the growing season. However, by the following spring, both March and June divisions had produced plants of similar size and appearance, while plants grown from August divisions were smaller and of lower quality. [ABSTRACT FROM AUTHOR]

Container production of nursery crops is intensive and a potential source of nitrogen release to the environment. This study was conducted to determine if trickle irrigation could be used by container nursery producers as an alternative to standard overhead irrigation to reduce nitrogen release into the environment. The effect of overhead irrigation and trickle irrigation on leachate nitrate N concentration, flow‐weighted nitrate N concentration, leachate volume, and plant growth was investigated using containerized rhododendron (Rhododendron catawbiense Michx. 'Album') supplied with a controlled‐release fertilizer and grown outdoors on top of soil‐monolith lysimeters. Leachate was collected over two growing seasons and overwinter periods, and natural precipitation was allowed as a component of the system. Precipitation accounted for 69% of the water entering the overhead‐irrigated system and 80% of the water entering the trickle‐irrigated system. Leachate from fertilized plants exceeded the USEPA limit of 10 mg L−1 at several times and reached a maximum of 26 mg L−1 with trickle irrigation. Average annual loss of nitrate N in leachate for fertilized treatments was 51.8 and 60.5 kg ha−1 for the overhead and trickle treatments, respectively. Average annual flow‐weighted concentration of nitrate N in leachate of fertilized plants was 7.2 mg L−1 for overhead irrigation and 12.7 mg L−1 for trickle irrigation. Trickle irrigation did not reduce the amount of nitrate N leached from nursery containers when compared with overhead irrigation because precipitation nullified the potential benefits of reduced leaching fractions and irrigation inputs provided under trickle irrigation. [ABSTRACT FROM AUTHOR]

Focuses on the characterization of tissue proliferation with reference to the habituated Rhododendron `montego' (Ericaceae) cultures. Propagation of a significant proportion of rhododendron; How tissue proliferation is characterized; Observation of an abnormal phenotype.