8,753 research outputs found
Discovery of non-climacteric and suppressed climacteric bud sport mutations originating from a climacteric Japanese plum cultivar (Prunus salicina Lindl.).
Japanese plums are classified as climacteric; however, some economically important cultivars selected in California produce very little ethylene and require long ripening both "on" and "off" the tree to reach eating-ripe firmness. To unravel the ripening behavior of different Japanese plum cultivars, ripening was examined in the absence (air) or in the presence of ethylene or propylene (an ethylene analog) following a treatment or not with 1-methylcyclopropene (1-MCP, an ethylene action inhibitor). Detailed physiological studies revealed for the first time three distinct ripening types in plum fruit: climacteric, suppressed-climacteric, and non-climacteric. Responding to exogenous ethylene or propylene, the slow-softening supressed-climacteric cultivars produced detectable amounts of ethylene, in contrast to the novel non-climacteric cultivar that produced no ethylene and softened extremely slowly. Genetic analysis using microsatellite markers produced identical DNA profiles for the climacteric cultivars "Santa Rosa" and "July Santa Rosa," the suppressed-climacteric cultivars "Late Santa Rosa," "Casselman," and "Roysum" and the novel non-climacteric "Sweet Miriam," as expected since historic records present most of these cultivars as bud-sport mutations derived initially from "Santa Rosa." This present study provides a novel fruit system to address the molecular basis of ripening and to develop markers that assist breeders in providing high-quality stone fruit cultivars that can remain "on-tree," increasing fruit flavor, saving harvesting costs, and potentially reducing the need for low-temperature storage during postharvest handling
An annotated checklist of Wisconsin sap and short-winged flower beetles (Coleoptera: Nitidulidae, Kateretidae)
A survey of Wisconsin Nitidulidae and Kateretidae yielded 78 species through analysis of literature records, museum and private collections, and three years of field research (2000-2002). Twenty-seven species (35% of the Wisconsin fauna) represent new state records, having never been previously recorded from the state. Wisconsin distribution, along with relevant collecting techniques and natural history information, are summarized. The Wisconsin nitidulid and kateretid faunae are compared to reconstructed and updated faunal lists for Illinois, Indiana, Michigan, Minnesota, Ohio, and south-central Canada. Literature and distributional records suggest at least 11 additional nitidulid species may occur in Wisconsin
Genome-wide DNA-(de)methylation is associated with Noninfectious Bud-failure exhibition in Almond (Prunus dulcis [Mill.] D.A.Webb).
Noninfectious bud-failure (BF) remains a major threat to almond production in California, particularly with the recent rapid expansion of acreage and as more intensive cultural practices and modern cultivars are adopted. BF has been shown to be inherited in both vegetative and sexual progeny, with exhibition related to the age and propagation history of scion clonal sources. These characteristics suggest an epigenetic influence, such as the loss of juvenility mediated by DNA-(de)methylation. Various degrees of BF have been reported among cultivars as well as within sources of clonal propagation of the same cultivar. Genome-wide methylation profiles for different clones within almond genotypes were developed to examine their association with BF levels and association with the chronological time from initial propagation. The degree of BF exhibition was found to be associated with DNA-(de)methylation and clonal age, which suggests that epigenetic changes associated with ageing may be involved in the differential exhibition of BF within and among almond clones. Research is needed to investigate the potential of DNA-(de)methylation status as a predictor for BF as well as for effective strategies to improve clonal selection against age related deterioration. This is the first report of an epigenetic-related disorder threatening a major tree crop
The potential for using a free-growth system in the rehabilitation of poorly performing pole-stage broadleaf stands
peer-reviewedThis paper is a literature review of the free-growth system, which may have potential for the rehabilitation of some poorly-performing pole-stage broadleaf stands. It involves releasing of a selected number of good quality stems from crown competition as a basis for the final crop. Generally, only stems with crowns adjacent to the potential final crop trees are removed. The aim is to increase diameter growth of the selected stems and thereby shorten the rotation
length needed to achieve a given diameter. The treatment may result in a greater incidence of epicormic shoots, particularly in oak (Quercus spp.). To maintain stem quality, epicormics may need to be removed, which may make the free-growth system uneconomic. There is, however, some evidence to believe that this may not be the case. In addition, the free-growth system may also be applicable in species less prone to epicormics, such as ash (Fraxinus excelsior L.) and sycamore (Acer pseudoplatanus L.). The free-growth system may prove to be a useful system for the rehabilitation of poorly performing pole-stage broadleaf stands and, with the advent of Chalara ash dieback (caused by Hymenoscyphus pseudoalbidus V. Queloz et al.) in Ireland, may gain greater use for its ability to reduce rotation lengths.COFOR
The Inheritance of Diagnostic Larval Traits for Interspecific Hybrids of \u3ci\u3ePapilio Canadensis\u3c/i\u3e and \u3ci\u3eP. Glaucus\u3c/i\u3e (Lepidoptera: Papilionidae)
Traits distinguishing the closely related tiger swallowtail butterfly species, Papilio canadensis and P. glaucus, include fixed differences in diagnostic sex-linked and autosomal allozymes as well as sex-linked diapause regulation, and sex-linked differences in oviposition behavior. Larval detoxification abilities for plants of the Salicaceae and Magnoliaceae families are dramatically different and basically diagnostic as well. The distinguishing morphological traits of the adults and larvae have not been genetically characterized. Here we describe the segregation of diagnostic larval banding traits in offspring from the 2 species in their hybrid and reciprocal backcross combinations. Elucidation of genetic basis, and linkage relationships of a suite of distinguishing biochemical, physiological, morphological, and ecological traits with regard to their geographic concordance across the hybrid zone is fundamental to understanding the pattern and process of speciation
Transcriptional regulatory networks controlling woolliness in peach in response to preharvest gibberellin application and cold storage
BACKGROUND: Postharvest fruit conservation relies on low temperatures and manipulations of hormone metabolism to maintain sensory properties. Peaches are susceptible to chilling injuries, such as ‘woolliness’ that is caused by juice loss leading to a ‘wooly’ fruit texture. Application of gibberellic acid at the initial stages of pit hardening impairs woolliness incidence, however the mechanisms controlling the response remain unknown. We have employed genome wide transcriptional profiling to investigate the effects of gibberellic acid application and cold storage on harvested peaches. RESULTS: Approximately half of the investigated genes exhibited significant differential expression in response to the treatments. Cellular and developmental process gene ontologies were overrepresented among the differentially regulated genes, whereas sequences in cell death and immune response categories were underrepresented. Gene set enrichment demonstrated a predominant role of cold storage in repressing the transcription of genes associated to cell wall metabolism. In contrast, genes involved in hormone responses exhibited a more complex transcriptional response, indicating an extensive network of crosstalk between hormone signaling and low temperatures. Time course transcriptional analyses demonstrate the large contribution of gene expression regulation on the biochemical changes leading to woolliness in peach. CONCLUSION: Overall, our results provide insights on the mechanisms controlling the complex phenotypes associated to postharvest textural changes in peach and suggest that hormone mediated reprogramming previous to pit hardening affects the onset of chilling injuries. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12870-015-0659-2) contains supplementary material, which is available to authorized users
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Seed germination and in vitro regeneration of the African medicinal and pesticidal plant, Bobgunnia madagascariensis
Propagation of the medicinal and pesticidal tree, Bobgunnia madagascarensis is difficult due to poor and erratic germination of its seeds and slow growth of its seedlings. This study involved two separate experiments. The first evaluated the effect of pre-sowing treatments and growing medium on ex vitro seed germination and early seedling development. The second experiment involved in vitro germination, shoot initiation and rooting of shoots. Pre-sowing seed treatments involved soaking seeds in cold and hot water for 12 and 24 h and soaking in different concentrations (0, 100, 200, 400 and 800 mg/l) of gibberellic acid for 24 h. Soaking of seeds in cold or hot water for up to 24 h did not achieve more than 45% germination, while seeds treated with gibberellic acid achieved 76%) when seeds were sown in a growing medium without compost compared with a medium with compost (<43%). All shoot-tips isolated from the in vitro germinated seedlings on B5 media without plant growth regulators continued to grow as a single shoot, while shoot-tips cultured on B5 supplemented with 0.1 mg/l of naphthaleneacetic acid (NAA) and thidiazuron (TDZ) produced two shoots each after four weeks. It was concluded that B. madagascariensis seeds had very low ex vitro germination percentages. Although, in vitro cultures improved seed germination, axillary shoot multiplication and rooting were not satisfactory. Therefore, further studies are needed to develop an optimal in vitro multiplication protocol for B. madagascariensis
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