GENETICS, BREEDING, SEED PRODUCTION
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.
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.
VARIETY STUDY AND PLANT INTRODUCTION
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.
AGRICULTURAL CHEMISTRY, SOIL SCIENCE AND AGROECOLOGY
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.
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.
MODERN TECHNOLOGIES OF STORAGE AND PROCESSING OF PRODUCTION
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.
ISSN 2618-9003 (Online)