The estimated global production of raspberry from year 2016 to 2020 averaged 846,515 tons. The most common cultivated
spp. is European red raspberry (
L. subsp.
). Often cultivated for its high ...nutritional value, the red raspberry (
) is susceptible to multiple viruses that lead to yield loss. These viruses are transmitted through different mechanisms, of which one is invertebrate vectors. Aphids and nematodes are known to be vectors of specific raspberry viruses. However, there are still other potential raspberry virus vectors that are not well-studied. This review aimed to provide an overview of studies related to this topic. All the known invertebrates feeding on raspberry were summarized. Eight species of aphids and seven species of plant-parasitic nematodes were the only proven raspberry virus vectors. In addition, the eriophyid mite,
, has been suggested as the natural vector of raspberry leaf blotch virus based on the current available evidence. Interactions between vector and non-vector herbivore may promote the spread of raspberry viruses. As a conclusion, there are still multiple aspects of this topic that require further studies to get a better understanding of the interactions among the viral pathogens, invertebrate vectors, and non-vectors in the raspberry agroecosystem. Eventually, this will assist in development of better pest management strategies.
Shallot (
Allium cepa
var.
aggregatum
), a small bulb onion, is widely grown in the world. We previously reported a droplet-vitrification for cryopreservation of in vitro-grown shoot tips of shallot ...genotype ‘10603’. The present study further evaluated rooting, vegetative growth, bulb production and contents of biochemical compounds, as well as genetic stability in cryo-derived plants. The results showed no significant differences in rooting, vegetative growth, bulb production and contents of soluble sugars and flavonols between the cryo- and in vitro-derived plants. Analyses of ISSR and AFLP markers did not detect any polymorphic bands in the cryo-derived plants. These results indicate rooting and vegetative growth ability, biochemical compounds and genetic stability were maintained in cryo-derived plants. The present study provides experimental evidences that support the use of cryopreservation method for long-term preservation of genetic resources of shallots and other
Allium
species.
Key message
Rooting, vegetative growth, bulb production, genetic stability and biochemical compounds were maintained in cryopreserved plants of shallot. Our results support use of cryopreservation for long-term preservation of shallot germplasm.
Cryopreservation is considered an ideal strategy for the long-term preservation of plant genetic resources. Significant progress was achieved over the past several decades, resulting in the ...successful cryopreservation of the genetic resources of diverse plant species. Cryopreservation procedures often employ in vitro culture techniques and require the precise control of several steps, such as the excision of explants, preculture, osmo- and cryoprotection, dehydration, freeze-thaw cycle, unloading, and post-culture for the recovery of plants. These processes create a stressful environment and cause reactive oxygen species (ROS)-induced oxidative stress, which is detrimental to the growth and regeneration of tissues and plants from cryopreserved tissues. ROS-induced oxidative stresses were documented to induce (epi)genetic and somatic variations. Therefore, the development of true-to-type regenerants of the source germplasm is of primary concern in the application of plant cryopreservation technology. The present article provides a comprehensive assessment of epigenetic and genetic integrity, metabolic stability, and field performance of cryopreserved plants developed in the past decade. Potential areas and the directions of future research in plant cryopreservation are also proposed.
Raspberry plants, valued for their fruits, are vulnerable to a range of viruses that adversely affect their yield and quality. Utilizing high-throughput sequencing (HTS), we identified a novel virus, ...tentatively named raspberry enamovirus 1 (RaEV1), in three distinct raspberry plants. This study provides a comprehensive characterization of RaEV1, focusing on its genomic structure, phylogeny, and possible transmission routes. Analysis of nearly complete genomes from 14 RaEV1 isolates highlighted regions of variance, particularly marked by indel events. The evidence from phylogenetic and sequence analyses supports the classification of RaEV1 as a distinct species within the
genus. Among the 289 plant and 168 invertebrate samples analyzed, RaEV1 was detected in 10.4% and 0.4%, respectively. Most detections occurred in plants that were also infected with other common raspberry viruses. The virus was present in both commercial and wild raspberries, indicating the potential of wild plants to act as viral reservoirs. Experiments involving aphids as potential vectors demonstrated their ability to acquire RaEV1 but not to successfully transmit it to plants.
Apple stem grooving virus (ASGV) is one of the most widespread and asymptomatic main viruses, that restricts the production of apples worldwide. Establishment of rapid, simple, and effective early ...detection methods of apple virus is important. In this study, we established and optimized a one-step reverse transcription - recombinase polymerase amplification (RT-RPA) method, using the target-specific primers of ASGV coat protein gene sequence, and M-MLV reverse transcriptase. This method could be completed within 30 min at 40 °C, followed by a visual detection of the results within 5 min by using lateral flow dipstick (LFD). The specificity results showed that only samples infected with ASGV showed a test line, while no test line appeared in the ASGV-negative samples. In addition, when crude extract of leaves was used, the whole detection could be completed within 1 h, which was shortened by 4 to 6 times compared with the RT-PCR method. The detection made on more field samples showed that the RT-RPA-LFD method is of high stability and reliability for ASGV diagnosis, with a great potential in the rapid on-site detection of plant viruses.
Abstract The adoption of the European Green Deal will limit acaricide use in high value crops like raspberry, to be replaced by biological control and other alternative strategies. More basic ...knowledge on mites in such crops is then necessary, like species, density, and their role as vectors of plant diseases. This study had four aims, focusing on raspberry leaves at northern altitude: (1) identify mite species; (2) study mite population densities; (3) investigate mite intra-plant distribution; (4) investigate co-occurrence of phytophagous mites, raspberry leaf blotch disorder and raspberry leaf blotch virus (RLBV). Four sites in south-eastern Norway were sampled five times. Floricanes from different parts of the sites were collected, taking one leaf from each of the upper, middle, and bottom zones of the cane. Mites were extracted with a washing technique and processed for species identification and RLBV detection. Mites and leaves were tested for RLBV by reverse transcription polymerase chain reaction (RT-PCR) with virus-specific primers. Phytophagous mites, Phyllocoptes gracilis , Tetranychus urticae , and Neotetranychus rubi , and predatory mites, Anystis baccarum and Typhlodromus ( Typhlodromus ) pyri were identified. All phytophagous mites in cultivated raspberry preferred the upper zone of floricanes, while in non-cultivated raspberry, they preferred the middle zone. The presence of phytophagous mites did not lead to raspberry leaf blotch disorder during this study. RLBV was detected in 1.3% of the sampled plants, none of them with leaf blotch symptoms, and in 4.3% of P. gracilis samples, and in some spider mite samples, implying that Tetranychids could also be vectors of RLBV.
The presence of viral diseases poses a significant challenge to the high-quality, efficient, and sustainable production of apples. Virus eradication and the use of virus-free plants are currently the ...most crucial method for preventing viral diseases. Among the viruses affecting apples, apple stem grooving virus (ASGV) and apple chlorotic leaf spot virus (ACLSV) present particular challenges in efficient eradication from apples. This study investigated the effects of exogenous salicylic acid (SA) treatment on the efficient eradication of ASGV and ACLSV from apple cultivar ‘Yanfu 8’. Shoots were excised from in vitro 4-week-old stock and cultured in shoot proliferation medium supplemented with 10 μM SA combining thermotherapy with shoot tip culture or cryotherapy for ASGV and ACLSV eradication. The results showed that including of 10 μM SA in thermotherapy significantly reduced the concentrations of ASGV and ACLSV by 33% and 14% in shoots compared to thermotherapy without SA. SA treatment also improved the shoot tips survival and regrowth after combining 2 or 4 weeks of thermotherapy followed by shoot tip culture or shoot tip cryotherapy, while maintaining the higher (75–100%) of virus eradication efficiencies. Therefore, the application of SA in combination with thermotherapy followed or not by cryotherapy proves to be a promising approach for enhancing the efficiency of virus eradication in apple.
Key Message
The establishment of a salicylic acid combining thermotherapy with shoot tip culture or cryotherapy of apple shoots provided technical support for the eradication of apple viruses in apple plants.
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