Endophytic Bacillus subtilis P10 from Prunus cerasifera as a biocontrol agent against tomato Verticillium wilt

Endophytic bacteria serve key roles in the maintenance of plant health and growth. Few studies to date, however, have explored the antagonistic and plant growth-promoting (PGP) properties of Prunus cerasifera endophytes. To that end, we isolated endophytic bacteria from P. cerasifera tissue samples and used a dual culture plate assay to screen these microbes for antagonistic activity against Verticillium dahliae, Botryosphaeria dothidea, Fusarium oxysporum, F. graminearum, and F. moniliforme. Of the 36 strains of isolated bacteria, four (strains P1, P10, P16, and P20) exhibited antagonistic effects against all five model pathogens, and the P10 strain exhibited the strongest antagonistic to five pathogens. This P10 strain was then characterized in-depth via phenotypic assessments, physiological analyses, and 16s rDNA sequencing, revealing it to be a strain of Bacillus subtilis. Application of a P10 cell suspension (1×108 CFU/mL) significantly enhanced the seed germination and seedling growth of tomato in a greenhouse setting. This P10 strain further significantly suppressed tomato Verticillium wilt with much lower disease incidence and disease index scores being observed following P10 treatment relative to untreated plants in pot-based experiments. Tomato plants that had been treated with strain P10 also enhanced defense-related enzymes, peroxidase, superoxide dismutase, and catalase activity upon V. dahliae challenge relative to plants that had not been treated with this endophytic bacterium. The results revealed that the P10 bacterial strain has potential value as a biocontrol agent for use in the prevention of tomato Verticillium wilt.

Change of Several Plant Nutrient Elements by Plant Species and Organ

Nutrient elements, one of the major factors shaping plant development, are the major components of plants, and, after being taken from the soil, they are present in different organs of plant at different concentrations. The speciation of nutrient elements within plant body is vital importance for determining the contribution to plant development, knowing the transfer between organs within the body of organs, clearly understanding the factors influencing plant development, and shaping the plant development. In the present study, the change of the concentrations of K and Mg (macronutrient elements) and Cu (micronutrient elements) by species and organ in woody species Prunus cerasifera, Platanus orientalis, Acer negundo, Fraxinus excelsior, Catalpa bignonioides, Aesculus hippocastanum, and Tilia platypyllos. As a result, it was found that the changes of elements by species were statistically significant in all the organs, and, in general, the highest concentrations were observed in leaves. The study results revealed that the concentrations of these elements might significantly vary between the organs in the same species, which varies significantly by the species.

Contribution to the floras of Lipetsk and Voronezh Regions (new vascular plant records from Usmansky pine forest)

The materials presented in the article supplement the information of “Flora of the middle zone of the European part of Russia” (Maevskiy, 2014) for the floras of Voronezh and Lipetsk Regions. The materials were collected in the period 2007–2020 on the protected areas of Usmansky Bor: in the Voronezhsky State Reserve, its protected zone and in the Federal Preserve “Voronezhsky”. The flora of the Lipetsk Region is supplemented by 9 species: Alchemilla argutiserrata, Aronia mitschurinii, Carex remota, C. tomentosa, Centaurea majorovii, Cotoneaster lucidus, Hieracium sylvularum, Scirpoides holoschoenus, Symphoricarpos albus. The data on 11 new taxa are given for the Voronezh Region flora: Cotoneaster lucidus, Crataegus ucrainica, Hieracium sylvularum, Nymphaea × marliacea, Phytolacca acinosa, Philadelphus latifolius, P. serotina, Spiraea chamaedryfolia, Thuja occidentalis, Veronica polita, Wolffia globosa. The article reports on new finds of Carex bohemica and Prunus cerasifera, species that were previously noted in the region, but not included in “Flora ...” (Maevskiy, 2014). Among the 20 marked species, 11 taxa are alien ornamental plants and fruit trees and shrubs noted outside of cultivation areas. Leaving the places of cultivation by alien plants and naturalization in natural communities is a modern problem of protected areas in the European part of Russia.

MACROELEMENTS CONCENTRATION IN PLUM TREE LEAVES AND SOIL IN RESPONSE TO ORCHARD FLOOR MANAGEMENT

The aim of the study was to determine the influence of various methods of orchard floor management on extractable mactronutrients concentration in plum leaves and orchard soil. Study carried out between 2013 and 2015. Standard mineral fertilization on experimental plots was applied. Trees of ‘Valjevka’ plum (Prunus domestica L.), grafted onto Myrobalan seedlings (Prunus cerasifera Ehrh. var. divaricata Ledeb.), were planted in the spring of 2008. From 2009 to 2015, the following methods of soil cultivation under tree canopies were introduced: control with limited weeding around tree trunks; spraying with foliar herbicides; mulching with organic waste, i.e. straw with compost; mechanical soil cultivation with the use of rotary cultivators and hoe; weed mowing. The method of soil cultivation had influence on leaf concentration of phosphorus, potassium, magnesium and calcium, as well as soil concentration content of phosphorus, potassium, and magnesium in particular years of the study or as three-year mean. Orchard floor management did not affect leaf nitrogen concentration in any way. The results showed that regular weed control in the evaluated type of orchard is not necessary for properly supplying plum trees with macronutrients.

The assessment of dispersal potential of the wax cicada Say. (Homoptera: Fulgoroidea: Flatidae) in the agricultural landscape of the Krasnodar Territory vineyards

Цель исследований заключалась в уточнении перечня кормовых растений восковой (белой, цитрусовой) цикадки ( Metcalfa pruinosa Say.) в агроландшафте виноградников и анализе состояния популяции путем определения гендерной структуры в основных зонах виноградарства Краснодарского края. Исследования проводили в 2015-2020 гг. на промышленных насаждениях винограда, в лесополосах и на другой растительности в агроландшафте виноградников согласно общепринятым методикам. Уточнена гостальная пищевая специализация вредителя, к наиболее заселяемым растениям отнесены Gleditsia triacanthos L., Crataegus laevigata Poir., Rosa majalis Herrm., Prunus spinosa L., Rubus fruticosus L., Prunus armeniaca L., Prunus domestica L., Prunus cerasifera Ehrh., Abutilon theophrasti Medik.; установлено отсутствие сортовых предпочтений M. pruinosa при развитии на растениях винограда. Результаты изучения гендерной структуры популяций M. pruinosa показали преобладание самок над самцами в Анапо-Таманской, Черноморской и Южно-предгорной зонах виноградарства Краснодарского края, что позволяет сделать предположение о том, что потенциал расселения восковой цикадки еще не исчерпан, вид продолжает осваивать данную территорию. The aim of the research was to adjust the list of forage plants of the wax (white, citrus) cicada ( Metcalfa pruinosa Say.) in the agricultural landscape of vineyards and to analyze the population conditions by determining the gender structure in the main viticultural zones of the Krasnodar Territory. The research was carried out in 2015-2020 in industrial grape plantings, forest belts and other vegetation in the agricultural landscape of vineyards according to generally accepted methods. The official nutrition specialization of the pest was adjusted, the most populated plants were Gleditsia triacanthos L., Crataegus laevigata Poir., Rosa majalis Herrm., Prunus spinosa L., Rubus fruticosus L., Prunus armeniaca L., Prunus domestica L., Prunus cerasifera Ehrh., Abutilon theophrasti Medik.; the absence of varietal preferences of M. pruinosa when developing on grape plants was established. Results of the study of the gender structure of M. pruinosa populations showed the predominance of females over males in the Anapa-Taman, Black Sea and South-Piedmont zones of viticulture in the Krasnodar Territory, suggesting the potential for dispersal of the wax cicada has not yet been exhausted, the species continues to develop this territory.

Pollution Monitoring using the Leaf-deposited Particulates and Magnetism of the Leaves of 23 Plant Species in a Semi-arid City, Northwest China

We conducted a study of the leaf-deposited particles and magnetism of plant leaves in different functional areas (traffic areas, parks and residential areas) in Lanzhou, China. The saturation isothermal remanence (SIRM) of the washed and unwashed leaves of 23 plant species (including evergreen shrubs, deciduous shrubs, deciduous liana species and deciduous trees) at three sampling heights (0.5 m, 1.5 m and 2.5 m) was measured. In addition, the mass of the leaf-deposited particles was measured using the elution-filtration method and the leaf morphological characteristics were determined by scanning electronic microscope (SEM) analysis. The results revealed significant differences in particles retention capacity among the 23 plant species, with evergreen shrub species at the heights of 0.5 m and 1.5 m having higher particles concentrations. Buxus sinica, Buxus megistophylla, Prunus cerasifera and Ligustrum×vicaryi were the most effective plant species for accumulating particles. The SEM results showed that leaves with a relatively complex adaxial surface (such as deep grooves and protrusions) were more effective at accumulating particles. The SIRM of washed leaves, unwashed leaves and leaf-deposited particles were significantly higher in traffic areas than in parks and residential areas. In addition, significant correlations were found between SIRM of unwashed leaves and leaf-deposited particles and the mass of leaf-deposited particles, and therefore the leaf magnetic properties effectively reflect levels of PM pollution under different environmental conditions. Overall, our results provide a valuable reference for the selection of plant species with high particle retention capacity that suitable for urban greening and pollution mitigation.

Pomological Characteristics and Ploidy Levels of Japanese Plum (Prunus salicina Lindl.) Cultivars Preserved in Poland

Research on the resistance to frost, susceptibility to sharka, flowering biology, fruit setting, yield, and ploidy levels of 36 Japanese plum cultivars (mostly hybrids of Prunus salicina with Prunus cerasifera) were carried out in 2015–2020 at the Experimental Orchard located in Dąbrowice near Skierniewice. Relatively mild winters with sporadic temperature drops to nearly −21 °C in January of 2017 and 2018 caused slight damage to several cultivars of Japanese plum insufficiently resistant to frost. The trees of most cultivars remained healthy, with no signs of damage. ‘Barkhatnaya’ and ‘Tatyana’ cultivars turned out to be very susceptible to sharka. ‘Herkules’ trees were the most vigorous. ‘Barkhatnaja’, ‘Blue Gigant’, ‘Shater’, and ‘Tatyana’ trees were characterized by weak growth. The trees of Japanese plum started flowering early, usually in the first or second decade of April. Most of the cultivars belonged to early season cultivars, the fruits of which ripened in July. Based on the assessment of tree productivity, ‘Barkhatnaya’, ‘Inese’, ‘Shater’, ‘Tatyana’, and ‘Vanier’ are the best for growing in the climate of Central Europe. ‘Tsernushka’, ‘Chuk’, ‘Dofi Sandra’, ‘Early Golden’, ‘Ewierch Rannyj’, ‘Yevraziya’, ‘Gek’, ‘General’, ‘Kometa’, ‘Kometa Late’, ‘Maschenka’, and ‘Naidyona’ trees also yielded well. ‘Blue Gigant’, ‘Black Amber’, and ‘Herkules’ had the largest fruits, and ‘Chuk’ and ‘Inese’ cultivars produced the smallest fruits. Among the assessed Japanese plum cultivars, those with round fruit, dark skin with various shades of purple, yellow flesh, and A cytometric analysis showed that almost all cultivars are diploid, except for ‘Herkules’ (possibly pentaploid) and ‘Yevraziya’ (possibly hexaploid or aneuploid).