Main soil nutrients dynamics in sod-dressing intercropped orchard

The study aimed to estimate seasonal dynamics of soil nitrogen, phosphorus and potassium under the influence of sod grasses in a sod-dressing intercropped orchard. The trial was conducted in a Welsey apple 1987-year orchard. Trees were planted at 8×6 m, cultivar seedlings used as rootstock. Red clover and meadow timothy in variant shares were used for interrow sodding. The cereal—legume intercropping was done in 2015, preceded by a 180 kg/ha active substance phosphorus-potassium dressing in reserve. Nitrogen was applied annually prior to growing season at 34.4 kg/ha active substance. Grass biomass in first hay cutting was the highest and comprised 45.3-49.9 % total mass. A total four cuttings dry mass was 3.36-7.10 t/ha depending on scheme. The maximum biomass was registered for the schemes with red clover and meadow timothy at ratios 1:1 and 7:3 (6.52 and 7.10 t/ha). In the growing period, grass depleted soil for 111.1—219.9 kg/ha nitrogen, 21.5-42.7 kg/ha phosphorus and 209.3—380.8 kg/ha potassium. Such consumptions suggest a serious competition for soil nutrients between grass vegetation and fruit trees. The available phosphorus and potassium content was independent of interrow dressing schemes. Inter-scheme differences did not exceed experimental bias due to presowing phosphorus and potassium application in reserve before trial. By first cutting, the nitrate nitrogen soil content in sodding schemes was 1.5-2-fold less vs. bare fallow, i.e. more nitrogen is used by vegetating grass, and its available forms recover slower than being consumed.

Taxonomic structure of tissue endophytic bacterial microbiome in clonal apple rootstock grown on sod-podzolic soils with variant properties

The taxonomic structure of tissue endophytic bacterial microbiome was comparatively studied in microplants (undifferentiated explant callus tissues, passage 25) and 5-year clonal apple rootstocks 57-490 and 54-118 cultured from corresponding tissues (passage 1) on sod-podzolic soils with variant granulometry, chemical, physical and physicochemical properties. Proteobacteria (91.6 %) predominated in vitro tissues among other endophytic bacterial phyla in rootstock 57-490, while Proteobacteria (52.5 %) and Firmicutes (47.4 %) — in rootstock 54-118. The endophytic Firmicutes ratio vs. in vitro tissues decreases (0.7-2.0 %) in roots and more severely (0-0.2 %) in leaves. Endophytic Actinobacteriota are revealed in 11.7 % in roots of the study rootstock in heavy loam soil, whilst in medium loam their ratio drops to 2.74.1 % in roots and 0.1-0.2 % in leaves. The phylogenetic diversity indices estimation for main endophytic bacterial phyla in apple rootstock tissue recovers their essentially lower diversity and evenness in culture endosphere (Shannon index 0.42-1.00) vs. open soil roots (1.34-2.08). The leaves Shannon index is typically low (0.06-0.13) indicating poor diversity and evenness of the main endophytic bacterial phyla.

Frontenac Gris as colour-mutant Frontenac grape variety

The work aimed to assess the cultivation and breeding prospects of the new Frontenac Gris technical grape variety obtained in 2003 by clonal selection as a colour-mutant Frontenac red technical grape originated by the University of Minnesota, USA. The variety is a complex cross-species hybrid with early maturity in the zone of Novocherkassk, Rostov Region. The variety was studied in 2018-2020 following the common viticulture and winemaking protocols at an experimental plot of the Novocherkassk trial field of All-Russian Research Institute of Viticulture and Winemaking named after Ya.I. Potapenko — Branch of the Federal Rostov Agricultural Research Centre. Vineyards were uncovered, unirrigated, grafted, Berlandieri×Riparia Kober 5BB rootstock, 3×1.5 m planting scheme. Formation as medium-standard double-shouldered horizontal cordon. By combination of economic value and agrobiological traits (cold and winter hardiness, yield, anti-phytopathogen resistance, high wine material quality), the Frontenac Gris variety holds promise in industrial viticulture. It can be recommended for gardening in sufficiently humid cool climates avoiding winter bush sheltering, as well as for breeding. The variety is low-hardy to drought and summer heat, which hinders its growing in the southern country. The variety’s disadvantages are in early maturity and slight berries wilting on bush in dry and windy air, which can pose an issue in juice production from pressed berries.

Nomenclature standards and DNA barcoding of apple varieties originated by VIR Crimean Experimental Breeding Station

Current pace of breeding technologies relies on a tighter control of quality and identity of breeding achievements. Thereby, standardised variety nomenclature becomes of particular relevance to store original genetic information and warrant authenticity of the breeding product. A nomenclature standard regulates the variety’s name and habitus. A herbarium specimen is most appropriate for standardisation, since it defines a set of strongly inherited morphological characters for a variety. Nomenclature standards must be permanently stored in a scientific herbarium collection. The N. I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) in alliance with national plant breeders initiated a first nomenclature standard collection of national-breeding cultivars. Aside to classical herbarising, the collection utilises molecular genetic techniques, particularly genotyping, to enable extended variety verification. The VIR team has developed the nomenclature standards of six apple varieties originated by the Crimean Experimental Breeding Station, a VIR Branch (Beloe Solntse, Zolotoy Potok, Kubanochka, Leto Krasnoe, Luchistoe and Shchedrost). The standards are supplemented with DNA barcodes obtained jointly with the N. I. Vavilov Institute of General Genetics. Fifteen microsatellite markers were used for barcoding. The herbarium nomenclature specimens adhered to the VIR-developed protocol in accordance with the International Code of Nomenclature for Cultivated Plants (ICNCP). The specimens are registered in the VIR Herbarium database and deposited in the World Crop Wild and Weed Relatives (WIR) Herbarium type collection.

Thermal dependencies of fruit puree density

Density is among the key properties of liquid food media, affecting homogenisation and dispersion. The work aimed to study the temperature effect on fruit puree density, determine temperature constants and grade purees by density. The study included apple, pear and cherry plum purees. Pycnometric densities were measured at 20, 30, 40 and 50ºC temperatures. Different media were shown to vary in the density reduction rate at increasing measurement temperatures. The correlation coefficient was strongly dependent on the reference (baseline) density and extremely — on temperature coefficient. Correlation dynamics modelling of elevating temperature revealed the slope vs. temperature coefficient pairwise correlation to monotonously increase starting from very high baseline values of >0.999. The relative slope vs. baseline density pairwise correlation coefficient decreased monotonously from 0.9032. It was additionally found that the media density grading is temperature-dependent. Thus, the descending series was pear–apple–cherry plum at 0–+24.68ºC, pear–cherry plum–apple at +24.68–+84.34ºC, cherry plum–pear–apple at +84.34–+174.31ºC and cherry plum–apple–pear at ≥+174.31ºC. For three study media, the number of temperature ranges inducing puree density gradients was 4. This approach to study thermal impact on the density of food fluids is generally acknowledged and can be successfully applied in the areas, where physical density and its comparative assessment are substantive.

Advances and outlook of horticultural bioengineering

A Branch of modern biotechnology for creating unique relevant genotypes is bioengineering that harnesses a spectrum of plant genome modification technologies. The study aimed to analyse the current state of the art in genome modification of fruit and berry crops for more significant (vs. premium pure breeding varieties) deviations of norm in the traits and properties of biotic and abiotic resistance, productivity, fruit quality, etc. First horticultural crop transformation studies aimed at developing protocols based on selectable enzyme marker genes of phosphorylationmediated aminoglycoside antibiotics detoxification. Neomycin phosphotransferase nptII constitutes the most common system of transgenic fruit and berry crop selection. In pome crops, the transgenic selection priorities were resistance to scab (Venturia inaequalis (Wint.) Cke), rust (Gymnosporangium juniper-virginianae Schwein.) and bacterial blight (Erwinia amylovora Burrill, Winslow et al.), higher fruit quality, including bright colouring, and reduced enzymatic browning. In stone crops, it was tolerance to plum pox (PPV), papaya ringspot (PRSV) and Prunus necrotic ringspot (PNRSV) viruses. In berry crops — resistance to Sphaerotheca humuli (DC.) Burrill fungus, grey mould (Botrytis cinerea Pers.), root rot (Phytophthora cactorum (Lebert & Cohn) J.Schrot.) and powdery mildew (Oidium tuckeri Berkeley), as well as higher fruit quality. In citruses — resistance to bacterial canker (Xanthomonas citri sub sp.), citrus ulcer (Xanthomonas axonopodis pv citri), greening disease (Huanglongbing (HLB)) and fungi (Trichoderma harzianum Rifai). In tropical crops — resistance to papaya ringspot (PRSV) and banana streak (eBSV) viruses. Unique FT-phenotype transgenic fruit lines are leveraged in the new FasTrack breeding strategy. Nine fruit and berry transgenic crop lines have now been registered worldwide. Transgenic Arctic apples (Golden, Granny, Fuji), plums (Honey Sweet) and papaya (Rainbow, SunUp, Laie Gold) are industry-approved in fresh and processed form. The transgenic list regulated in the Russian Federation does not include fruit or berry crops.

Microwave treatment for improved quality and safety of dehydrated pitted apricots

Dehydrated pitted apricots are widely used as a ready meal ingredient, which renders control of their quality and safety a relevant issue. Pitted apricots are rich in sugars, moisture and organic acids that serve a good medium for microorganisms. Therefore, these products require presale processing. Microwave treatment proved effective for the processing of raw and finished food products. Its impact on microorganisms depends on variant criteria, including taxonomic affiliation, total counts, dielectric cell properties and the treatment dose. The research aimed to study death kinetics in the native dried apricot surface microflora and its growth during subsequent storage. In this respect, we have studied the microwave treatment impact on dried apricot surface microflora depending on treatment dose and determined the residual microflora growth rate during subsequent storage. The doses of 120, 180 and 240 kJ at a 200 W radiation power have been shown to reduce baseline contamination of dehydrated pitted apricots by three orders of magnitude. Statistical kinetics analyses demonstrated a retarded surface microflora growth during subsequent storage. Microwave doses of 120–240 kJ (accounting for ±0.4 lg CFU/g error) exhibited a similar microflora dynamics in subsequent storage. The exposure of dried apricots to a lowest microwave field of 120 kJ ensured stability of the product microbiological dynamics.

New varieties and promising hybrids of Pelargonium grandiflorum hybridium hort. in humid subtropics of Russia

A genetic collection of the genus Pelargonium L’Herit. ex Ait., with 40 % stock represented by Pelargoniumgrandiflorum hybridium hort., is originated at the Federal Subtropical Research Centre of the Russian Academy of Sciences. The main collection varieties, including Aristo, Elegance, Candy Flowers, Hazel and Bermuda, are foreign selections attaining their best qualities under optimal soil and climatic conditions. Cultivation in humid subtropics disturbs their growth and development, at the same time as deteriorating their productivity and ornamental value. The research aimed to study the hybrid stock towards the selection of hardiest, most ornamental and long-flowering forms corresponding to a specified variety model. The variety model developed for Russian subtropic agroclimate incorporated a main set of economically valuable and adaptively significant traits. Over 30 varietal crossbreedings have been conducted to select for promising recombinants and hybrid families. A high variability of phenotypic ornamental traits has been observed in the crosses offspring. We identified 15 promising hybrids from the total morphological trait combination. Adaptive selection against stress factors has been proved effective. The most successful combinations were Hazel Ripple x Yashma, Hazel Cherry x Rozovyy Briz and A. Darling x Rozovyy Briz. A subset of elite forms (Kd-15-43, Kr-16-28 and Kc-18-22) maximising the number of significant breeding traits have further been selected towards a higher total score (≥95). K.j.-17-15, Kq-18-04 and K.ya-16-03 were recognised promising for large-flowered form selection. The Yagodnyy Tsvet variety, Kv-18-01 and K.d.-18-09 hybrids (over 35 inflorescences) have been identified as sources for high flower production. K.p-17-65, Kr-16-28 and Kc-18-22 were the hybrids with flowering period exceeding 100 days. All crosses were based on Hazel as a maternal form sourcing the trait.

Biologisation impact on soil condition, grapevine mineral nutrition and productivity

The research aimed to study the combined effect of inter-row sodding with perennial grasses and biofertiliser applications (microbial preparations, MPs) on soil fertility and biological activity, as well as on mineral nutrition, productivity and quality of grapes. The experiment was conducted at a vineyard of the Shasla x Berlandieri 41B-rootstock Muskat Belyy variety nearby Sevastopol. The two-factor design was as follows. Sodding: with segetal vegetation (SV) or a mixture of seeded cereal and leguminous herbs (MHs). Microbial preparations: grapevine root system and soil bacterisation with MPs of various action, including Diazophyte nitrogen fixer, Phosphoenterin (PE) phosphate-mobiliser and a complex of microbial preparations (CMP) additionally containing Biopolycide bioprotector. In control, MPs were not applied with SV or MH sodding. Preparations were introduced in soil once a year prior to grapevine flowering at a dose of 200 g MP suspension per bush. Herbs were mown 5–6 times per season at 30–40 cm height. A combined sodding—MPs usage has been found to increase the nitrate content by 24–45, mobile P2O5 – by 16–21, exchangeable K2O – by 28–50 and organic matter – by 0.06–0.13 % relative to control. The greatest increase in N-NO3–K2O content was registered for the combination of MHs, Diazophyte and CMP; combined SV—CMP–MHs had the greatest impact on mobile P2O5 and organic matter. Biologisation enriched mineral grapevine nutrition, especially for P and K, as well as increased the bush productivity by 10–14 % (maximum in CMP–MHs) via improving the berry and bunch mass and grape quality via significantly increasing the sugar content and lowering acidity of wort. MHs–CMP maximized counts of agronomically valuable microorganisms involved in the organic and mineral nitrogen and phosphorus turnover (ammonifiers and oligotrophs by 120–130, amylolytics and phosphate mobilisers by 50–70 and oligonitrophilic by 50– 80 %). All usages contributed to soil enrichment with nutrients and humus.

Biologisation of production and technological processes in nursery farming

We conducted a retrospective analysis of national scientific and technological advances by technological design to manifest the demand for organisation processes remodelling towards the methods and approaches of the sixth design, especially in biotechnology. The article defines terms such as nursery, biologisation, promising technology and resource conservation. We analyse the fruit crop seedling production and structure of nursery-specific processes. We determine the main agrocenotic components most susceptible to chemical and technogenic impacts. Studies of soil fertility and biota prioritised the challenge of declined soil activity and biogenicity. We establish that an increased chemical pressure on fruit nursery agrocenoses leads to disturbances in benign microflora, microbiotic, acaro- and entomosystems, alters plant infection pathways and immune status. We report destructive manifestations of microbiotic, entomo- and acarosystems in agrocenoses via the emergence of new pathogenic fungal species, root rotting agents, vascular system necroses (tracheomycoses), resistant typically dominant pathogen strains, higher pathogenicity, the expansion of species list and ranges of bacterial communities, phytoplasmas, viruses and viroids, a more aggressive invasion of new pests, including stem pathogens, emerging hazardous adaptations in economically impactive phytophages. Furthermore, we consider the scientific and practical issues in fruit crop reproduction: sweeping off forms (genotypes) from selection, changes in infection pathways in candidate parental plants, reduced “plant — external environment” adaptation, impaired plant immunity under climatic and anthropogenic stress, selection of candidates with a higher production value under environmental stress burden, reduction of best-quality planting stock, seedling root system retardation, massive crown invasion with fungal and bacterial agents, inadequacy of trait databasing for promising varieties and genotyping techniques. The priority role of agrocenotic biologisation in sustainable fruit nursery is substantiated through adopting modern approaches, especially in biotechnology, based on molecular biology, biochemistry and genetic engineering.