Bird Cherry (Prunus padus L.) in history and culture of Ukrainian and other ethnicities

Aim. Decorative and confectionery-pharmaceutical value of bird cherry (Prunus padus L.), the complex history of the phytonyms’ formation, the transcendent symbolism and poetics of its image, ideas about bird cherry in different ethnic groups, and the pragmatic need to modernize the traditions they have preserved led to the need for necessitated research. Methods. The authors conducted the retrospective analysis of the formation of the bird cherry’s folklore image; revealed the formation of its modern scientific terminology and botanical nomenclature, attempts to preserve the symbolism of the bird cherry’s folk names in different ethnic groups for future generations and the prospects for introducing P. padus representatives in horticulture. The commonly used methods of theoretical analysis, systematization, comparison, and generalization of specialized literature have been applied (Hurrell et al., 2019). Results. Polyphilia of the subgenus Prunus subg. Padus (Mill.) Peterm. (=Prunus subg. Padus (Moench) Focke), debatable rank and status of P. padus species and the incompleteness of its taxonomy are confirmed. The autochthonous nature of bird cherry in Ukraine is supported by the richness of its dialect folk names. However, the dialect names of bird cherry were not always really motivated. They symbolized the plant in colorful verbal and poetic images and connected it with the oldest sacred traditions. Folk names and symbols of bird cherry in Ukrainian, Russian and Belarusian dialects, variants of its nomenclature and symbolism in the traditions of English-speaking ethnic groups, and the Spanish language's onomastic field had been discussed. Works on the bird cherry’s use in folk medicine and modern pharmacy, and prospects for attracting materials from Prunus spp. Collections of NDP “Sofiyivka” of NAS of Ukraine and experimental farm “Novokahovske” of the Rice Institute of NAS of Ukraine for gardening, horticulture, and breeding are characterized. Conclusions. The ambiguity of the bird cherry’s folklore image in the ideas of close Slavic ethnic groups, the connection of these ideas with the composition of the local dendrological flora, and the traditional value of P. padus and other representatives of the subgenus Padus for traditional and scientific medicine, the prospects of their introduction into horticulture, and the need to involve ethnobotanical lexemes in enlightenment are proved.

Gene Editing in Prunus Spp.: The Challenge of Adapting Regular Gene Transfer Procedures for Precision Breeding

Successfully gene editing (GE) in Prunus spp. has been delayed due to its woody nature presenting additional difficulties in both, proper regeneration protocols and designing efficient gene transfer techniques. The availability of adequate, single cell culture techniques for GE such as protoplast regeneration, is a limiting step for the genus and for this reason, the improvement of regular regeneration protocols and finding more efficient techniques for the delivery of the “editing reagents” seem to be a reasonable strategy to incorporate GE in the genus. During the last 10 years, we have focused our efforts optimizing some previous regeneration and gene transfer procedures for Japanese plum (P. salicina), sweet cherry (P. avium) and peach (P. persica) to incorporate them into a GE technology on these species. In parallel, delivery techniques for the CRISPR/Cas9 editing components, i.e., guide RNA (gRNA) and Cas9, have been developed with the aim of improving gene targeting efficiencies. In that line, using DNA virus-based replicons provides a significant improvement, as their replicational release from their carriers enables their enhanced expression. Here, we make a brief overview of the tissue culture and regeneration protocols we have developed for P. salicina, P. avium and P. persica, and then we proceed to describe the use of Bean yellow dwarf virus (BeYDV)-derived replicon vectors to express the editing reagents in vivo and to evaluate their editing capability on individuals derived from Agrobacterium-mediated gene transfer experiments of these species. We show part of our characterization assays using new BeYDV-derived vectors harboring multiple gRNAs, the Cas9 gene, and the green fluorescent protein reporter gene. We also describe a dedicated genome analysis tool, by which gRNA pairs can be designed to address gene deletions of the target genes and to predict off-target sequences. Finally, as an example, we show the general results describing GE of the peach TERMINAL FLOWER 1 gene and some preliminary characterizations of these materials.

Identification and Sequence Analysis of a Novel Ilarvirus Infecting Sweet Cherry

In the present study, we utilized high throughput and Sanger sequencing to determine the complete nucleotide sequence of a putative new ilarvirus species infecting sweet cherry, tentatively named prunus virus I (PrVI). The genome of PrVI is comprised of three RNA segments of 3474 nt (RNA1), 2911 nt (RNA2), and 2231 nt (RNA3) and features conserved motifs representative of the genus Ilarvirus. BlastN analysis revealed 68.1–71.9% nt identity of PrVI with strawberry necrotic shock virus (SNSV). In subsequent phylogenetic analysis, PrVI was grouped together with SNSV and blackberry chlorotic ringspot virus (BCRV), both members of subgroup 1 of ilarviruses. In addition, mini-scale surveys in stone fruit orchards revealed the presence of PrVI in a limited number of sweet cherries and in one peach tree. Overall, our data suggest that PrVI is a novel species of the genus Ilarvirus and it consists the fifth member of the genus that is currently known to infect Prunus spp.

In vitro co-culture system for Prunus spp. and Armillaria mellea in phenolic foam rooting matric

Armillaria and Desarmillaria spp. are causal agents of a devastating root-borne disease of peach. Breeding resistant rootstock requires a reliable screening tool. An in vitro co-culture screen designed for almond was modified by replacing agar-gelled medium with a more aerated phenolic foam and combining resistant and susceptible rootstocks (i.e., common garden experiment) and minimizes variation in inoculum pressure or rooting substrate among replicate vessels. Eight Prunus rootstocks tested (peach, plum, peach × plum, and choke cherry) were rooted and had no decline in health. Susceptible peach rootstock, ‘GF 305’, was cultured for 15 wk in phenolic foam in the same vessel with a resistant peach × plum hybrid, ‘MP-29’, inoculated with Armillaria mellea at week 5, that led to more severe shoot symptoms in the former after an additional 8 wk. This method accommodated peach genotypes that were difficult to root in agar medium. The difference during a uniform challenge with the A. mellea fungus recapitulates resistant/susceptible reactions. The phenolic foam-based co-culture method will work on many Prunus spp. of potential use in rootstock breeding.

Mesocriconema xenoplax predisposes Prunus spp. to bacterial canker.

This chapter discusses the economic importance, geographical distribution, recommended integrated management, and management optimization of Mesocriconema xenoplax. Economic importance of bacterial canker (Pseudomonas syringae pv. syringae) and future research requirements are also mentioned.