Growth Rhythm Research Articles

Bone microstructure analyses in ontogenetic series of Mesosaurus tenuidens from the early Permian of Brazil.

Osteohistological evidence is widely used to infer paleobiological traits of fossil vertebrates, such as ontogeny and growth rates. Mesosaurs, an enigmatic group of aquatic reptiles from the early Permian, are the most well-known Paleozoic amniotes from Africa and South America. Their fossils are abundant in South America, ranging from the central-west region of Brazil to the southernmost areas, as well as parts of Paraguay and Uruguay. In this contribution, we examined the bone microstructure of Mesosaurus tenuidens by analyzing thin sections of axial and appendicular elements of several specimens collected from various Brazilian sites. The microstructure of the bones showed minimal histological variability among elements, predominantly composed of parallel-fibered tissues, indicating slow growth rhythm, along with increased bone density attributed to pachyosteosclerosis. The cortical area consists of poorly vascularized parallel-fibered bone tissue, which was interrupted by multiple cyclical growth marks, some of them being supernumerary, suggesting a strong influence of seasonality. Moreover, the organization of growth marks suggests distinct life history trajectories among individuals collected from different outcrops, reflecting environmental heterogeneity throughout the basin. Internally, the endosteal domain exhibits greater vascularization compared to the cortices and frequently contained calcified cartilage. In the ontogenetic series, there was a progressive filling of the medullary region from small to large individuals. The presence of the External Fundamental System (a proxy indicating somatic maturity) was observed in femora and ribs, suggesting that determinate growth was already occurring in Permian mesosaurs and may not be an exclusive specialization of crown amniotes.

Integrating direct air capture with algal biofuel production to reduce cost, energy, and GHG emissions

We investigate the potential to reduce costs and greenhouse gas emissions of the utilization of direct air capture of CO2 (DAC) for the production of algal biofuel. We examine four integrated designs for a DAC system comprised of solid amine monolith adsorbents delivering CO2 at the required level for algae cultivation with a photobioreactor (PBR)-based fuel production facility. We show that the integration of DAC with this biofuel production facility provides cost and greenhouse gas emissions benefits. Heat integration decreases operating expenses by reducing energy demand for heating requirements. Mass integration, utilizing flue gas CO2 as a carbon source for the PBRs, decreases the DAC system scale, resulting in both capital and operating cost savings. The most advantageous option depends on the interplay of heat and mass integration while matching the diurnal rhythm of algal growth with the inherently steady pace and energy requirements of the DAC system and fuel production. For these technologies, the DAC-PBR mass and energy integration provides an 18 % cost reduction and a 50 % reduction in greenhouse gas emissions for the current state of the technology.

The Free-Running Circasemilunar Period Is Determined by Counting Circadian Clock Cycles in the Marine Midge Clunio Marinus.

Semilunar rhythms are found in numerous marine organisms, but the molecular mechanism and functional principles of endogenous circasemilunar clocks remain elusive. Here, we explore the connection between the free-running circasemilunar clock and the circadian clock in the marine midge Clunio marinus with three different chronobiological assays. First, we found that the free-running circasemilunar period of the adult emergence rhythm in C. marinus changes linearly with diel T-cycle length, supporting a day-counting mechanism. Second, under LD 6:6, periods of circasemilunar and circadian emergence were comparable to those under LD 12:12, indicating that the circasemilunar counter in C. marinus relies on endogenous circadian oscillations rather than external T-cycles. Finally, when desynchronizing the circadian clock with constant light, the free-running circasemilunar emergence rhythm disappeared as well, suggesting that it requires a synchronized circadian clock. These results oppose the long-held view that C. marinus' free-running circasemilunar clock operates independently of the circadian clock. In a broader evolutionary context, our results strengthen the idea that the circasemilunar clocks of dipterous insects are based on different functional principles compared to the circasemilunar or circalunar clocks of marine annelids and algae. These divergent clock principles may indicate multiple evolutionary origins of circasemilunar and circalunar clocks.

Timed receptor tyrosine kinase signaling couples the central and a peripheral circadian clock in Drosophila

Circadian clocks impose daily periodicities to behavior, physiology, and metabolism. This control is mediated by a central clock and by peripheral clocks, which are synchronized to provide the organism with a unified time through mechanisms that are not fully understood. Here, we characterized in Drosophila the cellular and molecular mechanisms involved in coupling the central clock and the peripheral clock located in the prothoracic gland (PG), which together control the circadian rhythm of emergence of adult flies. The time signal from central clock neurons is transmitted via small neuropeptide F (sNPF) to neurons that produce the neuropeptide Prothoracicotropic Hormone (PTTH), which is then translated into daily oscillations of Ca2+ concentration and PTTH levels. PTTH signaling is required at the end of metamorphosis and transmits time information to the PG through changes in the expression of the PTTH receptor tyrosine kinase (RTK), TORSO, and of ERK phosphorylation, a key component of PTTH transduction. In addition to PTTH, we demonstrate that signaling mediated by other RTKs contributes to the rhythmicity of emergence. Interestingly, the ligand to one of these receptors (Pvf2) plays an autocrine role in the PG, which may explain why both central brain and PG clocks are required for the circadian gating of emergence. Our findings show that the coupling between the central and the PG clock is unexpectedly complex and involves several RTKs that act in concert and could serve as a paradigm to understand how circadian clocks are coordinated.

Integrated Metabolome and Transcriptome Analysis of Gibberellins Mediated the Circadian Rhythm of Leaf Elongation by Regulating Lignin Synthesis in Maize.

Plant growth exhibits rhythmic characteristics, and gibberellins (GAs) are involved in regulating cell growth, but it is still unclear how GAs crosstalk with circadian rhythm to regulate cell elongation. The study analyzed growth characteristics of wild-type (WT), zmga3ox and zmga3ox with GA3 seedlings. We integrated metabolomes and transcriptomes to study the interaction between GAs and circadian rhythm in mediating leaf elongation. The rates of leaf growth were higher in WT than zmga3ox, and zmga3ox cell length was shorter when proliferated in darkness than light, and GA3 restored zmga3ox leaf growth. The differentially expressed genes (DEGs) between WT and zmga3ox were mainly enriched in hormone signaling and cell wall synthesis, while DEGs in zmga3ox were restored to WT by GA3. Moreover, the number of circadian DEGs that reached the peak expression in darkness was more than light, and the upregulated circadian DEGs were mainly enriched in cell wall synthesis. The differentially accumulated metabolites (DAMs) were mainly attributed to flavonoids and phenolic acid. Twenty-two DAMs showed rhythmic accumulation, especially enriched in lignin synthesis. The circadian DEGs ZmMYBr41/87 and ZmHB34/70 were identified as regulators of ZmHCT8 and ZmBM1, which were enzymes in lignin synthesis. Furthermore, GAs regulated ZmMYBr41/87 and ZmHB34/70 to modulate lignin biosynthesis for mediating leaf rhythmic growth.

Endogenous rhythmic growth and ectomycorrhizal fungi modulate priming of antiherbivore defences in subsequently formed new leaves of oak trees

Abstract Priming of plant defences provides increased plant protection against herbivores and reduces the allocation costs of defence. Defence priming in woody plants remains obscure, in particular, due to plant development traits such as endogenous rhythmic growth. By using bioassays with oak microcuttings (Quercus robur) and combining transcriptomic and metabolomic analyses, we investigated how leaf herbivory by Lymantria dispar and root inoculation with the ectomycorrhizal fungus Piloderma croceum prime oak defences. We further investigated how defence priming is modulated by the rhythmic growth of the oaks. A first herbivory challenge in oak leaves primed newly grown leaves for enhanced induction of jasmonic acid (JA)‐related direct defences, or enhanced emission of volatiles, depending on the specific growth stage at which the plants were first challenged. Root inoculation with Piloderma abolished the enhanced induction of JA‐related defences and volatile emission. Synthesis: Our results indicate that a first herbivore attack primes direct and indirect defences of newly formed oak leaves and that the specific display of defence priming is regulated by rhythmic growth, and modulated by the interaction Piloderma. Our results show that the priming memory in oaks can be transmitted to the next growth cycle, to the leaves of the new shoot unit.

How searcher shoots grow and branch in mature liana mats: the case of Merremia boisiana.

The proliferation of vigorous lianas usually forms liana canopies over the crowns of host trees and liana mats on the ground of open areas or large forest gaps. While research on liana canopies has increased significantly in recent decades, our understanding of liana mats remains limited. Merremia boisiana (Convolvulaceae), a fast-growing liana, forms mature liana mats that can persist for decades, characterized by numerous upright searcher shoots that extend from the liana mats in search of supports. However, the reasons behind the proliferation of these searchers, as well as their growth and branching patterns in mature liana mats that lack support, are not well understood. We hypothesize that searchers are an inevitable phase in the growth rhythm of M. boisiana within these mature liana mats. We tested our hypothesis by tracking the lifespan and status of M. boisiana searchers during the early, middle, and late periods of the year. Our findings reveal the following: (1) M. boisiana searchers exhibit apical dominance and have a short lifespan; over 95% of searchers lost their terminal buds within two months during the early period, while it took only one month during the middle and late periods. (2) The original lateral buds of the searchers also have a limited lifespan, yet the nodes can sprout new lateral buds after the loss of their originals. (3) With the withering of terminal buds, the total number of lateral shoots decreased, while the quantity of long lateral shoots (≥ 50 cm) and their elongation rates increased. (4) Each surviving segment of a searcher typically develops one or two long lateral shoots, none of which grow into searchers. We conclude that the shoots of M. boisiana in mature liana mats periodically alternate between searchers and stolons, collectively forming a zigzag branching system. The high rate of lateral bud resprouting may facilitate the rapid recovery of mature liana mats early in the year, while the reduced lifespan of searchers and limited number of long lateral shoots represent effective strategies for M. boisiana, balancing the investment and risk associated with foraging in mature liana mats.

Body surface mapping of P-waves in sinus rhythm to predict recurrence following cardioversion for atrial fibrillation.

Direct current cardioversion (DCCV) is used as elective and emergency rhythm control for atrial fibrillation (AF). We aimed to explore the role of P-wave parameters measured during sinus rhythm using body surface mapping (BSM) in predicting successful DCCV for persistent atrial fibrillation (persAF) at 12 months. This case-control study included 56 males >18 years old who underwent DCCV for persAF. P-wave parameter collection after DCCV for AF was done using 128 unipolar leads. A band-pass filter of 1-50 Hz was utilised. Corrected P-wave duration (PWDc), P-wave amplitude, and P-wave dispersion were measured to predict 12-month outcomes and time of recurrence. The mean age was 64 ± 4 years, and 23 patients (44%) were on amiodarone. The 12-month success rate was 44% (n = 23), while the rest reverted to AF after 2.6 ± 0.4 months. The parameters were comparable between successful and failed DCCV in the entire cohort and patients not on amiodarone. In patients on amiodarone, patients with failed arms had higher PWDc than those with successful arms (188 vs. 150 ms, P = 0.04). Receiver operator characteristic curve analysis for PWDc in the amiodarone cohort showed an area under the curve (AUC) of 0.75 and P = 0.049. A recurrence cut-off >161 ms had a sensitivity of 69% and a specificity of 100%, with a hazard ratio of 10.7, P = 0.004. The parameters were not predictive of the time of recurrence. In patients on amiodarone, increased PWDc measured using BSM was associated with higher AF recurrence at 12 months following DCCV for persAF.

Dynamics of rhizosphere microbial structure and function associated with the biennial bearing of moso bamboo

Moso bamboo (Phyllostachys edulis) is a valuable nontimber forestry product with a biennial cycle, producing abundant bamboo shoots within one year (on-year) and few shoots within the following year (off-year). Moso bamboo plants undergo clonal reproduction, resulting in similar genetic backgrounds. However, the number of moso bamboo shoots produced each year varies. Despite this variation, the impact of soil nutrients and the root microbiome on the biennial bearing of moso bamboo is poorly understood. We collected 139 soil samples and determined 14 major physicochemical properties of the rhizosphere, rhizoplane, and bulk soil in different seasons (i.e., the growing and deciduous seasons) and different years (i.e., on- and off-years). Based on 16S rRNA and metagenomic sequencing, major variations were found in the rhizospheric microbial composition during different seasons and years in the moso bamboo forest. Environmental driver analysis revealed that essential nutrients (i.e., SOC, TOC, TN, P, and NH4+) were the main drivers of the soil microbial community composition and were correlated with the on- and off-year cycles. Moreover, 19 MAGs were identified as important biomarkers that could distinguish on- and off-years. We found that both season and year influenced both the microbial community structure and functional pathways through the biosynthesis of nutrients that potentially interact with the moso bamboo growth rhythm, especially the on-year root-associated microbiome, which had a greater abundance of specific nutrients such as gibberellins and vitamin B6. This work provides a dynamic perspective of the differential responses of various on- and off-year microbial communities and enhances our understanding of bamboo soil microbiome biodiversity and stability.

The intra-annual rhythm of Pinus sylvestris growth-climate responses under a warming climate at its southern distribution limits

Warming climate has posed a pressing threat on boreal forests and an improved understanding of the intra-annual pattern of climatic influences on the tree growth can help interpret the response of boreal forest to climate change. Here, we systematically examined the growth-climate relationship, cambium phenology, and xylem cell dynamics of Pinus sylvestris (PS) to disentangle its intra-annual growth rhythm to external drivers and internal physiological process at its southern distribution limits across Eurasia. We showed the intra-annual rhythm of PS to temperature and precipitation is anti-phase and synchronous at its southern limits. Temperature had both promoting and inhibiting effects on PS growth over growing season where the growth-temperature response gradually changed from positive in winter-early spring to negative in late spring-summer, and then returned to positive in autumn. Precipitation enhanced PS growth in late spring-summer. Temperature dominated the intra-annual growth-climate response rhythm, and the response shifted to negative when temperature reached 13.72 °C in spring-summer and shifted to positive when temperature reached 17.41 °C in summer-autumn in Shenyang, respectively. A high water demand for the rapid earlywood cell formation in spring-summer and heat requirement for cambial cell division in summer-autumn caused the shifts in growth-temperature response, respectively. Climatic warming advances and prolongs the time of summer water availability that limits PS growth at its southern distribution limits and thus warming climate may pose a greater threat to the southern population of PS.

Intra-annual stable isotopes in the tree rings of Hymenaea courbaril as a proxy for hydroclimate variations in southern Amazonia

The hydrology of Amazonia is changing due to climate and land-use changes, especially in the southern region, which has warmed and dried faster than other tropical regions. Yet there are no long-term hydrological records to put these changes in a historical perspective. Here we investigate the use of tree-ring carbon (δ13C) and oxygen isotopes (δ18O) to assess the seasonal variation in climate for the southern Amazonia basin. We analysed the intra-annual variation of δ13C and δ18O in 10 segments of each tree ring from 2013 to 2017 from individuals of Hymenaea courbaril, a long-lived and widespread neotropical tree species. We find strong seasonal patterns of tree-ring δ13C supporting previous observations of annual growth rhythms for this species. The intra-annual variation in δ18O shows that the lowest values generally occur just after the middle point of ring formation, corresponding to the peak rainy season. We find strong correlations between the δ18O in the middle of the growth ring and vapour pressure deficit (r = 0.92, P = 0.02) and precipitation (r = −0.93, P = 0.02). We further find associations between the oxygen isotopic series and the discharge of the Araguaia basin’s main rivers during the rainy period. Our results show that these δ18O records are sensitive to fluctuations in rainfall and humidity, and thus to river discharge in the region. Longer reconstructions of based on tree-ring δ18O of Hymenaea courbaril could provide a novel proxy to assess past hydrological changes.

Ferdynand Ruszczyc: A Polish Painter at the Crossroads of Cultures

The oeuvre of beloved Polish painter Ferdynand Ruszczyc (1870–1936) reflected the patriotic Neo-Romantic landscape trend of the fin-de-siècle prevalent in Germany and the Nordic countries (Denmark, Finland, Norway, Sweden). It should be considered in the context of Nordic visual culture for two reasons: (1) until the affiliation of Central and Eastern European nations with the Soviet Union in the wake of World War Two, nations bordering the Baltic formed a single, fluid territory of cultural exchange, and (2) Ruszczyc’s oeuvre displays significant commonalities with dominant patriotic and Neo-Romantic trends of progressive artists around the Baltic Sea, where landscape became a vehicle for expressing dreams and emotions, as well as love of homeland. This article situates Ruszczyc’s national and artistic identity at the crossroads of cultures and artistic impulses, regional as well as international. Ruszczyc was born in Bohdanów near Vilnius (now Belarus) to a Polish father and a Danish mother. Like many Polish artists from the Russian partition, he was educated at the Imperial Academy of Fine Arts in St. Petersburg, where he studied with Ivan Shishkin (1832–1898) and Arkhip Kuindzhi (1878–1910). He also travelled to Sweden. Ruszczyc was influenced by the Russian art circle Mir Iskusstva (World of Art, est. 1898) and is often compared with Nordic (e.g., Akseli Gallen-Kallela; Finnish, 1865–1931) and German (e.g., Otto Modersohn; 1865–1943) artists. His visions of nature are sometimes raw monumental images of the northern landscape or fairy-tale fantasies containing symbolic allusiveness and a mythical, poetic element that evoke intimate memories of the land of his childhood. In his paintings, Ruszczyc presented the changeability of seasons, orchards, soil and streams, clouds formations, and tree trunks with palpable emotion. By exposing the material substance of nature, his paintings also reveal its mystical aspect, its ability to transform in accordance with the cyclical, cosmic rhythm of growth, maturation, death, and rebirth.

Crucial roles of the optimal time-scale of water condition on grassland biomass estimation on Qinghai–Tibet Plateau

The effect of the time-scale of water conditions on vegetation productivity has been widely studied by the academic community. However, the relationship between the time-scale of water conditions and the vegetation growth rhythm and the effect of this relationship on vegetation biomass estimation have rarely been discussed. Here, we analyzed the occurrence times of major phenological events on alpine grasslands using the widely distributed “site-dominant species” dataset and set a series of time-scales for accumulated precipitation and standardized precipitation evapotranspiration index based on phenological information. Then, we combined large-scale aboveground/belowground biomass datasets to evaluate the role of the optimal time-scale for water conditions in aboveground/belowground biomass estimation. The results showed that (1) the optimal time-scale for water conditions with the greatest effects on aboveground biomass was on the month before the end of flowering or the onset of fruit maturity. The optimal time-scale for water condition effects on belowground biomass was earlier and longer than that for the aboveground biomass. The optimal time-scales for accumulated precipitation and standardized precipitation evapotranspiration index effects on belowground biomass were at five months before the end of flowering or the beginning of fruit ripening and the three months before the first flowering, respectively. (2) The aboveground and belowground biomass were underestimated by 11 % and 9 %, respectively, when the water conditions at the optimal time-scales were ignored. (3) The interannual variability in aboveground/belowground biomass was more effectively captured by considering the optimal time-scales of water conditions, especially in water-restricted areas. Overall, this study indicated that terrestrial carbon cycle models should incorporate information on the lag-effects of the water conditions in previous periods. In the future, increasing the number of belowground biomass observations and conducting monthly belowground biomass monitoring sooner will be key to revealing the mechanisms of the belowground biomass response to climate change.

Peculiarities of seasonal development of species of the genera Sedum L. and Hylotelephium H. Ohba in the conditions of Kryvorizhzhia

Resulted results of research of seasonal development of species of the genera Sedum L. and Hylotelephium Н. Ohba in the conditions of Kryvorizhzhia during 2003–2021 years. In the conditions of the steppe zone of Ukraine, global climate changes are associated with rising temperatures and prolonged droughts, especially during the period of active vegetation of plants. This leads to the creation of stressful conditions for the vital activity of plants used in landscaping. In this regard, plants change the rhythms of growth and development, adapting to the climatic conditions of the area of growth. The limiting factors are mainly air temperature and daily photoperiod. The purpose of the work is to determine the phenology features of individual species of the genera Sedum and Hylotelephium at introduction into the Kryvyi Rih Botanical Garden of the National Academy of Sciences of Ukraine under the influence of climate change. The objects of the study were Sedum aizoon L., S. album L., S. florіferum Praeg., S. hybridum L., S. reflexum L., S. spurium M. Bieb., S. takesimense Nakai, Hylotelephiuт ewersii (Ledeb.) H. Ohba, H. spectabile (Boreau) H. Ohba. The increase in annual air temperature caused changes in the timing and duration of certain phases of development of the vegetative and generative spheres. Accordingly, there was an increase in the growing season by 20–50 days. When introduced to the Kryvyi Rih Botanical Garden of the National Academy of Sciences of Ukraine, S. floriferum, S. takesimense and S. spurium change their phenotype from winter-green to spring-summer-autumn-green. It has been observed that S. album, S. reflexum, S. spurium, S. floriferum, S. hybridum and S. takesimense, which flower in July in their natural habitats, begin bloom in June аn Kryvorizhzhia, and in 2017–2021 the timing is accelerated – it is already the end of May–beginning of June. The difference in time reached 12–18 days. The average duration of flowering sedums was 22–30 days. During 2003–2021, the duration of flowering increased reliably in S. aizoon, S. floriferum and S. reflexum. In the conditions of Kryvorizhzhia, the species S. floriferum, S. takesimense and S. spurium change their development strategy – they do not vegetate in the winter period and bloom in June, which is not typical for them in the conditions of natural habitats. There is also a change in the flowering period to the early-summer period in S. album, S. reflexum and S. hybridum, which are summer-flowering. The identified features of the seasonal rhythm of development indicate a significant level of plasticity of the studied species.

Effects of Electroplating Effluents on Growth, Heavy Metals Accumulation and Concentrations in Amaranthus viridis Lin.

Pollution in recent times has become prevalent due to industrial expansion, hence, releasing pollutants into the environment. Thus, this study aimed at investigating the effects of effluents from electroplating companies on growth, heavy metals accumulation and concentrations in Amaranthus viridis. Seeds of A. viridis were obtained from the National Institute of Horticulture, Ibadan. Loam soils were collected from Lagos State University and two samples of electroplating effluents were obtained from Oregun, Lagos. Seeds were sown, nursed, and transplanted in a uniform bucket filled with 5 kg loam soil and transplanted seedlings were treated with Effluent A (5 and 10% conc.) and Effluent B (5 and 10% conc.) and control respectively. Growth parameters such as plant height and so on were measured and plant samples harvested were analyzed for heavy metal concentrations using Atomic Absorption Spectrophotometer. Data collected were subjected to a one-way analysis of variance. Results revealed that Effluents A and B are highly acidic and above discharge limits. Also, the result revealed that 5% conc. of Effluents A and B had more effects on growth (p < 0.05) of A. viridis across the harvests than 10% conc. in relation to control. This result showed that the effluent samples affect the growth rhythms of plants. Results further revealed vigorous accumulation of the heavy metals: Zn (241.66 µg kg–1 ± 0.10 at third harvest in Effluent A: 10%), Cu (68.25 µg kg–1 ± 0.23 at first harvest in Effluent B: 5%), Cr (500 µg kg–1 ± 0.90 in harvests at all concentrations.) and Ni (500 µg kg–1 ± 0.90 at third harvest in Effluent B: 5%) and all these metals are far above the control and permissible limits of WHO/FAO recommendations. From this study, it could be concluded that electroplating effluents had adverse effects on growth and increased metals’ bioaccumulation in A. viridis. Therefore, the treatment of effluents to enhance an eco-friendly environment should be done.

Burrow emergence rhythms of deep-water Mediterranean Norway lobsters (Nephrops norvegicus) revealed by acoustic telemetry

N. norvegicus supports one of the most commercially-important fisheries in the Mediterranean, and there is considerable interest in developing non-invasive sampling stock assessment methods. Currently, stock assessments are conducted via trawling or by UnderWater TeleVision (UWTV) surveys with limited capacity to provide direct population data due to the burrowing behavior of the species. Here, we used acoustic telemetry to characterize the burrow emergence and movement patterns of N. norvegicus in relation to internal tides and inertial currents in deep-sea habitats of the northwestern Mediterranean. We deployed acoustic tags on 25 adults between May and June 2019, and collected up to 4 months of detection data from each tag. Tagged lobsters spent approximately 12% of their time in door-keeping (i.e., detections at burrow entrance with no displacements) but differences existed among the different behavioral rhythms identified. We observed that mixed day-night, tidal and inertial rhythms in field settings were similar to those observed in laboratory tests. The presence of mixed day-night and tidal periodicity poses the question of why N. norvegicus exhibits flexible responses to environmental cues other than photoperiod. It is possible that tidal regulation of locomotor activity could reduce energy expenditure in relation to hydrodynamic drag. Inertial periodicity occurs in animals with no clear burrowing-oriented activity (always present on the seabed). Possibly, inertial-related movements are the result of a disruption of the biological clock. Our results are discussed in the context of how burrow emergence rhythms may bias UWTV surveys and how novel in situ monitoring approaches address these biases.

Maternal dominance of intergeneric hybridization between Lycoris and Clivia

Distant hybridization can expand genetic variations and is widely applied in plant breeding. Lycoris has high economic value, but the ornamental period is short. To prolong the florescence and leaf period of Lycoris, intergeneric hybridization between Lycoris and Clivia was conducted. The offspring bloomed 7–8 years after sowing. The characteristics of the offspring were observed from three dimensions: annual growth rhythm, morphological feature, and foliage anatomy structure. The hybrids were similar to the maternal plants (L. haywardii) with some variation, but did not show any paternal (C. nobilis) characteristics. The hybrid was identified by molecular marker, only a few paternal bands were amplified. The intergeneric hybrid exhibited absolute unilateral parent dominance that was few reported. This study offers innovative insight into the characteristics of distant hybrids.

Blue-red dual color emitting phosphor Cs2NaLuCl6: Sb3+, Ho3+ for plant growth LEDs

The phosphor-converted light emitting diode (pc-LED) is an efficient light source to adjust growth rhythm and raise yield of plant. Blue and red light play the dominant role in the process of plant growth, thus it is meaningful to search the blue-red dual emission phosphors with high quantum field and better thermal stability for developing plant growth LED. Herein, the blue-red dual emission phosphors were synthesized by co-doping Sb3+ and Ho3+ into the Cs2NaLuCl6, which emitted blue (454 nm) to red (657 nm) light with increasing the content of Ho3+ to 25% and their relative intensity could be tuned through adjusting the concentration of Ho3+ due to the efficient energy transfer from Sb3+ to Ho3+. The intensity of blue emission from Sb3+ and red emission from Ho3+ could maintain 78.4 and 75.8% of the room temperature at 150 °C, respectively. Furthermore, the spectra of fabricated blue and red LEDs match well with the absorption of carotenoid, Phytochrome and Chlorophyll b, implying the samples possess great application potential in plant growth LED.

Seasonal dynamics of shoots growth in <i>Forsythia ovata</i> Nakai plants: Rhythmicity of apical and radial growth

The aim of the study was to establish the type (linear or non-linear) and shape (presence of extremes and trends) of the time dependences of apical and radial growth rates for shoots of two types (branching and formation) in woody plants. The object of the study was an introduced in the Middle Urals ornamental early-flowering shrub species Forsythia ovata Nakai. Seasonal dynamics of morphometric parameters of two types of shoots, which differ in intensity of growth and origin (developing from the apical or dormant buds of the skeletal branch respectively), was examined. Also, there was made an assessment of their relationship with air temperature and precipitation values. Apical and radial growth are accompanied by oscillations of increments. The duration of individual phases of oscillations is about 7 or more days, which makes it possible to attribute this phenomenon to infradian growth rhythms. The weak relationship between the characteristics of the observed oscillations and weather conditions indicates the predominantly endogenous nature of the observed morphogenetic processes. The growth of formation shoots begins 4 weeks later than branching shoots. This delay is apparently related to the time necessary for activation of dormant bud growth. Seasonal dynamics curves of rates and accelerations of the apical and radial shoot’s growth have the shape of previously unobserved oscillations with phases fading in amplitude and changing in duration. The growth ends 1–2 months before the environmental conditions become unfavorable. The oscillations of the growth rate of shoots are apparently associated with the action of two or more differently directed factors, which determine the increase in volume of different segments of the shoot. These factors include the different contribution of cell division and elongation to the change in the geometric dimensions of the apical meristem domains. The main differences in the seasonal dynamics of the apical and radial increments for both types of shoots are: the duration of growth (6–8 and 4 weeks, respectively), the number of extremes, the amplitude and the duration of individual phases of oscillations. Higher amplitudes of the growth rate oscillations in shoots formation compared with branching shoots, cause bigger values of the formation shoots total increments. The dynamic curves of the apical growth rates have two maxima, while those of the radial growth have only one. Each type of growth, despite the delay in the onset of the formation shoots, has the same total duration. The shapes of curves of seasonal changes in speeds and accelerations of shoot growth values are also similar for different types of shoots. These similarities indicate that shoots have the same “programs” of growth regulation, ultimately determined by the genotype. The rhythmic growth of both types of shoots during the season suggests the existence of the relationship in time between the rates of division and growth of cells located in functionally different groups of cells in the apical meristem zone.

The effect of weather conditions on the seasonal rhythm of plant development of Amur cork tree (<i>Phellodendron amurense</i>rupr.) in the forest-steppe of the Ob region

Background. Amur cork tree is a valuable woody plant of great economic importance. Its bark, liber, leaves, and fruits are successfully used in medicine and cosmetology. This tree is very ornamental and serves as is a good honey plant. It can be a potential source of industrial cork. Due to its properties and relative unpretentiousness, Amur cork tree may be of interest for introduction. In this regard, the aim of the research was to study the peculiarities of the influence of weather conditions on the seasonal rhythm of plant development for Amur cork tree (Phellodendron amurense Rupr.) under the conditions of the foreststeppe in the Ob region.Materials and methods. Thirty two Amur cork trees were used as the material for the study. These trees were successfully introduced in the forest-steppe of the Ob region. Phenological observations to evaluate the rhythm of seasonal growth were carried out according to the methodological recommendations of I. D. Yurkevich and coauthors. The Pearson correlation coefficient (r) was used to identify the dependence of the rhythm of seasonal growth on weather conditions.Results. The plants of Amur cork tree were found to be successfully adapted to the conditions of the arboretum of the Siberian Research Institute of Plant Production and Breeding. It was shown that in the year with the highest sum of effective temperatures (2020), the duration of interphase periods was on average 2 days shorter than in other years. At the same time, in the coldest year (2018), the plants did not have time to complete their leaf fall before the snow cover appeared. The vegetation of Amur cork tree was observed to start in mid-May. The completion of the growing season varies greatly from year to year. Conclusion. It was established that the seasonal development of Amur cork tree in the forest-steppe of the Ob region corresponded to the features specific to the development of this species within its natural range.