Traditional Selection Potato Varieties and Their Resistance to the 28-punctata Potato Ladybug Henosepilachna vigintioctomaculata (Coleoptera: Coccinellidae) in the Southern Russian Far East

Background: Henosepilachna vigintioctomaculata is a polytrophic pest, causing the greatest damage to plants from the nightshade family. The study aimed to research the resistance of potato cultivars that are promising for breeding to damage by a potato ladybug in laboratory and field experiments. Methods: In laboratory experiments, the indicators of fertility, mortality and duration of development, morphological anomalies and the effect of potato varieties on the composition of Epilakhna’s hemolymph were studied. The sample consisted of 50 individuals with a slight predominance of females. The experiment used 13 varieties of potatoes. Result: A specific dependence of the frequency of phytophage anomalies on the variety was revealed. The influence of nutrition on survival and the timing of ontogenesis has been established. The results obtained indicate the high breeding value of the material when recommending it for cultivation in regions with a high number of pests, as well as when creating new varieties.

Optimisation of Nutrition of Early-Maturing Potato Varieties on Drip Irrigation in the South of Ukraine

Potatoes are an extremely important crop for the nutrition of the population in Ukraine. Its potential is high-up to 100 t/ha of tubers, but the average yield reaches 14-16 t/ha. To obtain significantly higher productivity, it is necessary to improve the main elements of cultivation technology. The main factor of potato production on drip irrigation is the optimisation of plant nutrition, which the authors have taken to study with three varieties of early maturing potatoes. Studies have established that providing plants with nutrients with the selection of varieties can increase the productivity of tubers up to 37-39 t/ha, or increase its level compared to the control to 64.7%. It was determined that the maximum yield is provided by the main application from autumn N32P32K32, before planting N48P48K48 and carrying out three top dressings during the growing season simultaneously with watering with a total rate of N33 and Plantafol 6 kg/ha, starting from the beginning of budding with an interval of 8-10 days. At the same time, tubers are formed with high-quality indicators as they contain a sufficient number of dry substances, ascorbic acid (vitamin C), and starch. It should be noted that when optimising nutrition, the intake of all the main indicators of potato tubers compared to the control slightly decreased, namely dry substances and starch. On the contrary, the amount of ascorbic acid increased, especially with top dressing with Plantafol. Varietal features regarding the impact on the quality of tubers are also determined. Significantly more dry substances were found in tubers of the Riviera and Prada varieties, and more starch content was found in Prada and Minerva varieties. Slightly less dry matter and ascorbic acid were detected in Minerva potato tubers compared to other varieties. From the grown crop of tubers of the studied potato varieties, it is possible to obtain up to 4.0 t/ha of bioethanol or alcohol if they are processed

Revealing the potential of potato varieties with colored pulp in the conditions of the Murmansk region

A collection of 15 potato varieties ‘Seyanets Stepana’, ‘Stepan’, ‘Yekzotika’, ‘Fioletik’, ‘Kubinka’, ‘Vasilok’, ‘Lekar’’, ‘Severnoye Siyaniye’, ‘Ametist’, ‘Gurman’, ‘Perlamutrovyy’, ‘Ves siniy’, ‘Ves krasnyy’, ‘Klyukvenno-krasnyy’, ‘Malina’ was studied in the Arctic North. All the studied accessions demonstrated antioxidant properties and suitability for dietetic and therapeutic nutrition. The study was conducted in accordance with the VIR Guidelines. During a three-year study, the studied varieties displayed purple (blue) and red tuber pulp coloration of varying degrees of intensity. Even the varieties with white flesh ‘Kubinka’ (к-25276), ‘Vasilok’ (к-25199) had a slightly colored pulp along the vascular ring. The trait of colored tuber pulp variability is determined at the gene level. Probably, the long Polar day and low air temperatures contributed to the intense biosynthesis of anthocyanins. When studying economically valuable traits in the conditions of the Murmansk region, almost all varieties behaved as late ripening and unsuitable for cultivation for early production. The standard variety ‘Khibinskiy ranniy’ produced an average of 520 g/bush with 76% marketability in the trial dig. By the final harvesting, the standard yields an average of 800 g/bush with 87% marketability. The highest values of early yield accumulation (79-80% of the standard) in the Arctic North were displayed by the varieties ‘Fioletik’ (k-24754) and ‘Severnoye Siyaniye’ (k-25344). High yields at the final harvest were characteristic of the varieties ‘Fioletik’ (k-24754), ‘Gurman’ (vr.k.-p 523), and ‘Perlamutrovyy’ (vr.k.-p 526). In terms of the starch content, the varieties ‘Kubinka’ (19,3%), ‘Yekzotika’ (15,2%), ‘Gurman’ (16,7%) ‘Fioletik’ (14,2%), ‘Lekar’’ (13,2%), ‘Perlamutrovyy’ (14,2%) were distinguished. The high starch content is likely due to meteorological conditions and the genetic characteristics of the varieties. All varieties show signs of late ripening. For cultivation in the Arctic North, the varieties ‘Fioletik’ (к-24754), ‘Severnoye Siyaniye’ (k-25344); ‘Gurman’ (vr.k.-p 523), ‘Perlamutrovyy’ (vr.k.-p 526), and ‘Klyukvenno-krasnyy’ (vr.k.-p 522) can be recommended.

Optimizing Plant Disease Management in Agricultural Ecosystems Through Rational In-Crop Diversification

Biodiversity plays multifaceted roles in societal development and ecological sustainability. In agricultural ecosystems, using biodiversity to mitigate plant diseases has received renewed attention in recent years but our knowledge of the best ways of using biodiversity to control plant diseases is still incomplete. In term of in-crop diversification, it is not clear how genetic diversity per se in host populations interacts with identifiable resistance and other functional traits of component genotypes to mitigate disease epidemics and what is the best way of structuring mixture populations. In this study, we created a series of host populations by mixing different numbers of potato varieties showing different late blight resistance levels in different proportions. The amount of naturally occurring late blight disease in the mixture populations was recorded weekly during the potato growing seasons. The percentage of disease reduction (PDR) in the mixture populations was calculated by comparing their observed late blight levels relative to that expected when they were planted in pure stands. We found that PDR in the mixtures increased as the number of varieties and the difference in host resistance (DHR) between the component varieties increased. However, the level of host resistance in the potato varieties had little impact on PDR. In mixtures involving two varieties, the optimum proportion of component varieties for the best PDR depended on their DHR, with an increasing skewness to one of the component varieties as the DHR between the component varieties increased. These results indicate that mixing crop varieties can significantly reduce disease epidemics in the field. To achieve the best disease mitigation, growers should include as many varieties as possible in mixtures or, if only two component mixtures are possible, increase DHR among the component varieties.

Identification of starch candidate genes using SLAF-seq and BSA strategies and development of related SNP-CAPS markers in tetraploid potato

Potato starch is an essential nutrient for humans and is widely used worldwide. Locating relevant genomic regions, mining stable genes and developing candidate gene markers can promote the breeding of new high-starch potato varieties. A total of 106 F1 individuals and their parents (YSP-4 × MIN-021) were used as test materials, from which 20 plants with high starch content and 20 with low starch content were selected to construct DNA pools for site-specific amplified fragment sequencing (SLAF-seq) and bulked segregation analysis (BSA). A genomic region related to the starch traits was first identified in the 0–5.62 Mb of chromosome 2 in tetraploid potato. In this section, a total of 41 non-synonymous genes, which were considered as candidate genes related to the starch trait, were annotated through a basic local alignment search tool (BLAST) search of multiple databases. Six candidate genes for starch (PGSC0003DMG400017793, PGSC0003DMG400035245, PGSC0003DMG400036713, PGSC0003DMG400040452, PGSC0003DMG400006636 and PGSC0003DMG400044547) were further explored. In addition, cleaved amplified polymorphic sequence (CAPS) markers were developed based on single nucleotide polymorphism (SNP) sites associated with the starch candidate genes. SNP-CAPS markers chr2-CAPS6 and chr2-CAPS21 were successfully developed and validated with the F2 population and 24 tetraploid potato varieties (lines). Functional analysis and cloning of the candidate genes associated with potato starch will be performed in further research, and the SNP-CAPS markers chr2-CAPS6 and chr2-CAPS21 can be further used in marker-assisted selection breeding of tetraploid potato varieties with high starch content.

The reaction of early-ripening potato varieties to the planting rate in the Middle Urals

The article presents the yield of early potato varieties, considering the different planting rates of tubers. A two-factor field experiment was conducted in 2013 - 2015 at the experimental field of the Perm State Agro-Technological University named after Academician. The purpose of the research is to find ways to cultivate early-ripening potato varieties to obtain a yield of 35 t/ha. The soils of the experimental site are sod-finely podzolic medium loamy. The humus content is 1.9 - 3.2%, pH (KCl) 4.4-5.1, P2O5 185-300 mg/kg, K2O 143-431 mg/kg. The meteorological conditions of the growing seasons were opposite in terms of weather conditions and did not equally affect the yield. It was found that, on average, over three years, the goal of the experiment was achieved only in one variant of the experiment - in the Rosalind variety with a maximum thickening of 71.4 thousand tubers per hectare. The limit of thickening in the Red Scarlett variety was at the maximum thickening of tubers when planting 71.4 thousand. The limit of thickening of the Luck variety was 47.6 thousand tubers, the limit of compaction of plantings in the Rosalind variety was 57.1 thousand tubers. Keywords: POTATO, VARIETY, YIELD, PLANTING RATE

Bacterial Community Is Affected by Locations and Time Rather Than Potato Varieties but Streptomyces spp. Are Related to Potato Varieties

Improved knowledge and a better understanding of the functions of bacterial communities are vital for effective crop disease management. This study was conducted to study a bacterial community’s relationship with the common scab in four different potato varieties (Dejima, DJ; Atlantic, DS; Seohong, SH; Haryeong, HY) at two different locations (Gangneung and Chuncheon) and spatial locations (rhizosphere and furrow) at two different times (preharvest and postharvest). In addition, metagenomic sequencing was performed by extracting genomic DNA from soil samples to observe the dominant bacterial microbes and disease severity of the common scab in all the tested varieties in spatial location and time. The results suggest that the most dominant bacterial phyla in all the soil samples were Proteobacteria, Acidobacteria, and Bacteroidetes. Additionally, Streptomyces spp. were found to be more abundant in the susceptible variety (DJ) than in other varieties (DS, SH, and HY). Interestingly, bacterial communities were found to be more diverse across the two different geographical locations, spatial locations, and harvesting times, rather than the variety of potato, according to PCoA analysis. There were no interlinked changes in bacterial communities among the varieties. Moreover, the 14 most dominant bacterial genus correlation networks with Streptomyces spp. suggested that there was a significant positive and negative correlation to some extent. Alpha and beta diversity results clearly indicated that the possible reason for differences in bacterial communities might have been due to the different spatial locations, in comparison with varieties, which suggests that there was no significant correlation between bacterial community richness and diversity among the varieties.