Evaluation of the aesthetic qualities and adaptability of introduced ornamental apple trees from the genetic collection of the Orenburg Branch of the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery

The study of ornamental and adaptive qualities of Malus Mill. from the genetic collection of ornamental crops of the Orenburg branch of the Research Center of Horticulture was carried out to assess the gene pool of introduced wild apple tree species and forms and identify suitable for the urban landscaping and the breeding process. Such characteristics as habitus, abundance of flowering, color and number of flowers in the inflorescence, color of vegetative organs, flowers and fruits during the season were taken into account; resistance to major diseases and adverse abiotic factors was evaluated. Additionally, the color of buds and flowers was characterized on the basis of the RHS (Royal Horticultural Society Color Chart). As a result of a preliminary survey on the complex of ornamental qualities and the level of adaptability, 5 most promising species were identified, which received the best ratings on the ornamental scale. Malus sikkimensis (Wenz.) Koehne ex C. K. Schneid. (31 points) was characterized by an attractive habit, the presence of flowers with a diameter of up to 40 mm and subsequently fruits that acquire a yellow-red color. Malus sargentii Rehder (29 points) was notable for its compact rounded crown, a large number of flowers with a diameter of 30 mm, followed by the formation of fruits with a dark red color. Malus floribunda Siebold ex Van Houtte (28 points) was distinguished by a large number of fragrant flowers in an umbrella-shaped inflorescence (5 — 7 pcs) with an average diameter of 30 mm, as well as attractive red-yellow fruits. Malus sieboldii (Regel) Rehder, M. toringo Siebold (28 points) was interesting primarily by the presence of 5 -7 flowers of 20 — 30 mm in the inflorescence and decorative fruits, the color of which varies from yellow to red. Malus niedzwetzkyana Dieck (28 points) attracted attention to the rich purple color of all organs due to the presence of a large number of anthocyanins, it was also worth noting the presence of a pleasant aroma during flowering and large flowers with an average diameter of 40 mm. The selected ornamental types of apple trees are favorable for use in landscaping of various scales, they are recommended for breeding work as initial parent forms.

Refinement of the methodology for assessing the resistance of hazel (hazelnuts) to stress factors

The aim of the research is to clarify the methodology for assessing the resistance of hazel (hazelnuts) to stress factors on the basis of uniform approaches adopted in walnut farming. The assessment of resistance to biotic and abiotic factors has been carried out according to the methods recommended for the walnut, and the state of the vegetative and generative organs of hazel (hazelnuts) has been correlated with the program requirements. The result has been the development of 7 point assessment scales and the numerical values of the degree of damage correlated with them. Score 0 corresponds to the absence of lesions, 1 – lesions up to 5%, 2 – lesions up to 6–10%, 3 – lesions up to 11–25%, 4 – lesions up to 26–50%, 5 – lesions up to 51–75%, 6 – lesions more than 75% or death of the whole plant (depending on the studied indicator). The assessment scale for the winter hardiness of vegetative organs takes into account the degree of damage to the apical buds, annual shoots, branches of two years and older, the stem and the whole plant. Damage to male inflorescences is determined by the length of their dead part, to the female flowers – by the number of damaged ones, expressed as a percentage. The degree of drought resistance is revealed on the basis of studying the state of the entire plant, the percentage of damaged and fallen leaves. The influence of drought on the loss of food part is established by the degree of shrinkage of the kernel. Susceptibility to diseases and pests is estimated in percentage points separately for leaves by area, shoots in length, nuts by the ratio of damaged and undamaged ones. We have distinguished 6 groups of resistance, depending on the degree of vulnerability of varieties and forms of hazel (hazelnuts). It has been proposed to draw conclusions on the basis of at least three years of observations, and the final conclusion should be focused on specific breeding goals.

INFLUENCE OF NITROGEN NUTRITION CONDITIONS AND PHYTHORMONES ON CHANGE OF FATTY ACID COMPOSITION OF VEGETATIVE ORGANS OF SPRING WHEAT TRITICUM AESTIVUM L.

The paper shows the effect of nitrogen nutrition, exogenous auxin, and rhizosphere auxin-synthesizing microorganisms on the variability of the composition of fatty acids (FA) in the vegetative organs of spring wheat. The object of the study was seedlings of spring soft wheat Triticum aestivum L. The determination of FAs was carried out by gas chromatography with mass spectrometry (GC-MS). Analysis of FAs showed that in the control variants (without auxin), nitrogen nutrition conditions did not affect the localization of polyunsaturated FAs in vegetative organs; the maximum content of triene FAs was observed in leaves of 48.30% (N-deficient variant) and 44.8% (NO-3-variant ) and the absence of these FAs in the roots. It was found that in the presence of nitrates, the proportion of unsaturated FAs in the leaves and roots of wheat decreases. The use of exogenous auxin (5–50 μg/ml) in the early stages of ontogenesis leads to an increase in the amount of saturated (palmitic and stearic) acids and a decrease in unsaturated acids in vegetative organs, regardless of the conditions of nitrogen nutrition. During the introduction of spring wheat seedlings by auxin-synthesizing microorganisms, it was noted that nitrogen-fixing bacteria affect the leaves of plants most effectively, the content of saturated FAs increases by 72%, and only 16% increases in these FAs in the leaves of nitrate-reducing microorganisms.

A Historical Perspective of Bladderworts (Utricularia): Traps, Carnivory and Body Architecture

The genus Utricularia includes around 250 species of carnivorous plants, commonly known as bladderworts. The generic name Utricularia was coined by Carolus Linnaeus in reference to the carnivorous organs (Utriculus in Latin) present in all species of the genus. Since the formal proposition by Linnaeus, many species of Utricularia were described, but only scarce information about the biology for most species is known. All Utricularia species are herbs with vegetative organs that do not follow traditional models of morphological classification. Since the formal description of Utricularia in the 18th century, the trap function has intrigued naturalists. Historically, the traps were regarded as floating organs, a common hypothesis that was maintained by different botanists. However, Charles Darwin was most likely the first naturalist to refute this idea, since even with the removal of all traps, the plants continued to float. More recently, due mainly to methodological advances, detailed studies on the trap function and mechanisms could be investigated. This review shows a historical perspective on Utricularia studies which focuses on the traps and body organization.

Interaction of Light Intensity and CO2 Concentration Alters Biomass Partitioning in Chrysanthemum

Biomass partitioning is one of the pivotal determinants of crop growth management, which is influenced by environmental cues. Light and CO2 are the main drivers of photosynthesis and biomass production in plants. In this study, the effects of CO2 levels: ambient 400 ppm (a[CO2]) and elevated to 1,000 ppm (e[CO2]) and different light intensities (75, 150, 300, 600 μmol·m−2·s−1 photosynthetic photon flux density – PPFD) were studied on the growth, yield, and biomass partitioning in chrysanthemum plants. The plants grown at higher light intensity had a higher dry weight (DW) of both the vegetative and floral organs. e[CO2] diminished the stimulating effect of more intensive light on the DW of vegetative organs, although it positively influenced inflorescence DW. The flowering time in plants grown at e[CO2] and light intensity of 600 μmol·m−2·s−1 occurred earlier than that of plants grown at a[CO2]. An increase in light intensity induced the allocation of biomass to inflorescence and e[CO2] enhanced the increasing effect of light on the partitioning of biomass toward the inflorescence. In both CO2 concentrations, the highest specific leaf area (SLA) was detected under the lowest light intensity, especially in plants grown at e[CO2]. In conclusion, elevated light intensity and CO2 direct the biomass toward inflorescence in chrysanthemum plants.

Redressing the roles of anthocyanin pigments in vegetative and reproductive organs

<p>Anthocyanin pigments are common in both reproductive and vegetative organs in plants, yet their functional significance is not entirely understood. While communicative functions have received considerable attention in reproductive organs and the role of anthocyanic colouration in frugivore and pollinator attraction is well understood, it has also been suggested that anthocyanins provide a communicative function in vegetative organs i.e. it may be that anthocyanic colouration in leaves deters herbivores by signalling a plant’s defensive investment. Conversely, there is evidence that anthocyanins in vegetative organs perform a number of physiological functions such as photoprotection and mitigation of various environmental stressors. While these physiological roles have received considerable attention in leaves, little is known about the applicability of these functions to anthocyanins in reproductive organs. There is evidently a gap in anthocyanin research; no study has provided unequivocal support for a communicative function for anthocyanins in vegetative organs and no study has shown that anthocyanins perform a physiological function in the reproductive organs in any species other than domesticated crop plants. To address this imbalance in anthocyanin research my thesis tested for a signalling role in vegetative organs, and then investigated a physiological role for anthocyanins in reproductive organs. In chapter two, I hypothesised that for Pseudowintera colorata, red (anthocyanic) leaf margins reduce leaf herbivory by signalling to herbivorous insects the presence of increased chemical defences. Using a natural population of P. colorata, I showed that leaves with the wider red margins contained higher concentrations of anthocyanins and polygodial, a sesquiterpene dialdehyde with known anti-feedant properties, and incurred less natural herbivory. Additionally, laboratory feeding trials involving a natural P. colorata herbivore, Ctenopseustis obliquana larvae, showed a preference for green-margined leaves over red, but only when feeding trials were conducted under light regimes which allowed discrimination of leaf colour. Collectively, my data show that red leaf margins provide a reliable and effective visual signal of chemical defence in P. colorata. Moreover, C. obliquana larvae apparently perceive and respond to the colour of leaf margins, rather than to olfactory cues. My study is therefore the first to provide direct support for a communicative function for anthocyanins in vegetative organs. In peduncles, rays and pedicels, the sterile components of an inflorescence, anthocyanin accumulation has exclusively been considered an adaptation to promote frugivore visitation; however, anthocyanins may instead be produced to mitigate light stress. In chapter three, I tested the requirements of a physiological function, that anthocyanins provide photoprotection for Sambucus nigra peduncles which turn red prior to fruit maturation. I found that accumulation of red pigmentation required exposure to full sunlight and that anthocyanins significantly reduced the quantity of green light that would normally reach chlorenchyma in the peduncle. Under saturating white light, red peduncles maintained higher quantum efficiencies of photosystem II compared to green peduncles, and red portions of peduncle recovered from photoinactivation more quickly than did green portions. My data are, therefore, the first to show that anthocyanins perform a physiological function in the reproductive organs of a naturalised species. In chapter four, I hypothesised that anthocyanin accumulation in senescing Sambucus canadensis peduncles prolongs senescence and enhances nitrogen resorption. Red peduncles possessed several traits indicative of a prolonged senescence; their rates of chlorophyll and xanthophyll decline were lower, while tensile strength and elasticity were higher than for green peduncles. Red peduncles were also less susceptible to photoinactivation than the green ones at the later stages of senescence. However, manipulating green peduncles with light filters possessing transmittance properties comparable to an anthocyanic tissue layer did not increase peduncle longevity or nitrogen resorption. I concluded that like senescing leaves, red peduncles display many characteristics indicative of a prolonged senescence, but I am unable to attribute this benefit to the presence of anthocyanins. This thesis provides a significant contribution to our understanding of the role of anthocyanins in plants in two ways: it is the first to directly demonstrate that anthocyanins perform a communicative function in vegetative organs, and is the first to show for a naturalised (non-cultivar) species, that anthocyanins perform a physiological function in reproductive organs.</p>