Search

Red raspberry is an economically important horticultural crop that is known for its fruit's sweet flavour and nutritional value. A reliable and economic genotyping platform is needed to facilitate clonal/variety identification. Previous attempts for clonal identification utilized morphological traits or low‐throughput, difficult to score dinucleotide‐containing simple sequence repeat molecular markers. Single nucleotide polymorphisms (SNPs), despite having lower allelic diversity, are numerous across the genome and more easily converted to high‐throughput assays restoring differential power. In this study, we use the kompetitive allele‐specific PCR (KASP™) chemistry, an affordable and high‐throughput platform, to develop a panel of SNPs to distinguish a diverse collection of red raspberry accessions for clonal identification. The panel consists of 48 KASP assays that show high concordance with whole genome sequencing, allelic balance, and recovery rate and a minimal set of 24 assays that distinguished the same accessions differentiated by the larger panel. [ABSTRACT FROM AUTHOR]

Key message: We have constructed a densely populated, saturated genetic linkage map of black raspberry and successfully placed a locus for aphid resistance. Abstract: Black raspberry ( Rubus occidentalis L.) is a high-value crop in the Pacific Northwest of North America with an international marketplace. Few genetic resources are readily available and little improvement has been achieved through breeding efforts to address production challenges involved in growing this crop. Contributing to its lack of improvement is low genetic diversity in elite cultivars and an untapped reservoir of genetic diversity from wild germplasm. In the Pacific Northwest, where most production is centered, the current standard commercial cultivar is highly susceptible to the aphid Amphorophora agathonica Hottes, which is a vector for the Raspberry mosaic virus complex. Infection with the virus complex leads to a rapid decline in plant health resulting in field replacement after only 3-4 growing seasons. Sources of aphid resistance have been identified in wild germplasm and are used to develop mapping populations to study the inheritance of these valuable traits. We have constructed a genetic linkage map using single-nucleotide polymorphism and transferable (primarily simple sequence repeat) markers for F population ORUS 4305 consisting of 115 progeny that segregate for aphid resistance. Our linkage map of seven linkage groups representing the seven haploid chromosomes of black raspberry consists of 274 markers on the maternal map and 292 markers on the paternal map including a morphological locus for aphid resistance. This is the first linkage map of black raspberry and will aid in developing markers for marker-assisted breeding, comparative mapping with other Rubus species, and enhancing the black raspberry genome assembly. [ABSTRACT FROM AUTHOR]

In the U.S., there has been a recent surge in Korean black raspberry products available and in the number of reports about this species appearing in the scientific literature. Despite this, the majority of products sold and the work carried out has been on Rubus occidentalis L., not R. coreanus Miquel. The importance of accurate recognition of all starting material is multiplied for research downstream, including genetics/genomics, plant breeding, phenolic identification, food processing improvements and pharmacokinetic investigations. An overview of distinguishing characteristics separating R. coreanus from R. occidentalis will be presented. Research conducted on correctly identified fruit will also be summarized to aid future studies that might showcase the unique qualities that bokbunja can offer. [ABSTRACT FROM AUTHOR]

• An SPME-GC/MS method to analyze bound volatiles in small fruits was optimized. • Enzymatic hydrolyses, primarily with pectinase, resulted in high levels of alcohols. • Heat-assisted citric acid hydrolyses led to artifacts generation, mainly aldehydes. • Blueberries were characterized by high levels of lipids oxidation derivatives. • Raspberries and grapes were marked by high amounts of shikimate pathway derivatives. Bound volatiles are odorless aroma reservoirs that modify flavor when released during food processing, and their determination is important to understand the aroma of fruit beverages. However, the generation of oxidation/degradation artifacts during analyses of glycosidically-bound volatiles has not been compared across fruit species and their dependence on diverse acidic and enzymatic hydrolytic conditions remains unclear. This work aimed to optimize and compare different hydrolytic conditions for the analysis of glycosidically-bound volatiles in blueberries, raspberries, and grapes with a solid-phase microextraction – gas chromatography/mass spectrometry (SPME-GC/MS) methodology. Enzymatic hydrolyses using AR2000® at 100 mg.mL−1 and Pectinex Ultra SPL® at 25–100 μL.mL−1 showed profiles characterized by the expected alcohols, while using AR2000® at 200–400 mg.mL−1 and citric acid at 50–100 mM resulted in profiles defined by artifacts (hydrocarbons, norisoprenoids, and aldehydes). (Z)-3-hexen-1-ol, 3-methyl-1-butanol, linalool, citronellol, and geraniol presented Odor Activity Values (OAV) > 1 for most small fruit genotypes. [ABSTRACT FROM AUTHOR]

Phytophthora root rot and wilting complex (PRRW) of red raspberry, caused primarily by Phytophthora rubi , is an economically important disease in British Columbia (BC) and in raspberry producing regions globally. Reliable, rapid, and efficient screening methods are lacking for evaluating germplasm for potential disease resistance in raspberry breeding programs as well as for screening pathogen isolates for virulence. The objective of this study was to compare various screening methods for efficiency and rapidity in inducing symptoms of disease to identify the most suitable approach. We compared several intact plant root inoculation (IPRI) assays, detached stem assays, and an intact plant stem inoculation (IPSI) assay. A virulent isolate of P. rubi was inoculated in two commercial cultivars: 'Chemainus' (susceptible to PRRW) and 'Cascade Bounty' (moderately resistant to PRRW). For IPRI assays, days to first symptom development, plant wilt progression, and root assessment were recorded. For detached stem tissue and IPSI assays, days to first visible lesions and lesion size were assessed. Experiments were arranged in a completely randomized design with three replications in each experiment. Three IPRI assays produced reliable symptoms in both cultivars. Among the detached stem assays, a node inoculation method performed better than other methods. Detached stem assays are useful for rapid pathogenicity testing of P. rubi , whereas IPRI assays are better for screening germplasm for disease resistance. Overall, this study identified several assays that can be used for conducting studies on pathogen phenotypic diversity (pathogenicity and virulence tests) and screening raspberry cultivars, germplasm, and breeding materials for response to PRRW.

In field-scale mass balance studies of poplar remediation of carbon tetrachloride (CT), more than 95% of the mass of CT was degraded with all of the CT chlorine accountable as chloride ion accumulation in the soil. Atmospheric loss of CT through leaf transpiration and trunk diffusion was insignificant. These findings are consistent with previously reported uptake and degradation of trichloroethylene (TCE) by poplar. Poplar phytoremediation of CT and TCE results in little decrease in aqueous concentration, since water is taken up at about the same rate as the chlorinated compounds. From this result we predict that phytoirrigation--the application of pumped contaminated groundwater to planted systems--will result in concentrations of the pollutants at the bottom of the root zone that are higher than permitted regulatory levels. Such plantations will be susceptible to loss of contaminants during rainfall events, possibly resulting in pollution of uncontaminated soil. Greenhouse studies of pollutant profiles in the media beneath poplar trees that were surface irrigated with TCE and CT confirmed that regulatory concentrations of these pollutants were not achieved in the root zone of the poplar; rather concentrations fell by less than 50%.