Growth Duration Research Articles

Effect of Climatic Conditions Caused by Seasons on Maize Yield, Kernel Filling and Weight in Central China

In order to evaluate the effects of climatic conditions on maize grain yield (GY), kernel weight (KW), and kernel filling and identify the optimal climatic factors for GY and KW, 2-year field experiments in three seasons, i.e., spring (SPM), summer (SUM), and autumn (AUM), on maize were conducted in Central China. The results showed that SUM had more growing degree days (GDDs) than SPM and AUM due to the higher mean temperature (MT), and also resulted in higher temperature stress (killing degree days (KDDs)) in maize growth duration. Meanwhile, after silking, SPM and SUM had more GDDs and KDDs than AUM because of the higher MT, and the accumulated solar radiation (Ra) for SUM was significantly higher than for SPM and AUM. The GY of SPM was significantly higher than that of SUM and AUM, while SUM’s GY was always the lowest, because the GDDGD, MTGD, and KDDGD played significantly negative roles on GY. The final KW for SUM was always the lowest, with GDD, MT, KDD, and Ra causing significantly negative effects, and M△T and precipitation having significant positive effects, resulting in a lower kernel filling rate during the linear kernel filling period (KFRlkf) and a lower GDD at the maximum kernel filling rate (GDDKFRmax). Maize KFRlkf has significant negative linear dependences on GDD, MT, and Ra. In summary, because of the higher MT, KDD, and GDD during maize growth and kernel filling duration negatively affecting the maize kernel filling rate, the GY and KW for SPM were the highest, and for SUM, they were the lowest; therefore, farmers should plant SPM first and then AUM in Central China.

Functional traits influence patterns in vegetative and reproductive plant phenology - a multi-botanical garden study.

Phenology has emerged as key indicator of the biological impacts of climate change, yet the role of functional traits constraining variation in herbaceous species' phenology has received little attention. Botanical gardens are ideal places in which to investigate large numbers of species growing under common climate conditions. We ask whether interspecific variation in plant phenology is influenced by differences in functional traits. We recorded onset, end, duration and intensity of initial growth, leafing out, leaf senescence, flowering and fruiting for 212 species across five botanical gardens in Germany. We measured functional traits, including plant height, absolute and specific leaf area, leaf dry matter content, leaf carbon and nitrogen content and seed mass and accounted for species' relatedness. Closely related species showed greater similarities in timing of phenological events than expected by chance, but species' traits had a high degree of explanatory power, pointing to paramount importance of species' life-history strategies. Taller plants showed later timing of initial growth, and flowered, fruited and underwent leaf senescence later. Large-leaved species had shorter flowering and fruiting durations. Taller, large-leaved species differ in their phenology and are more competitive than smaller, small-leaved species. We assume climate warming will change plant communities' competitive hierarchies with consequences for biodiversity.

Long-Term Persistence of Mitochondrial DNA Instability in HIV-Exposed Uninfected Children during and after Exposure to Antiretroviral Drugs and HIV.

HIV-exposed uninfected (HEU) children show impaired health outcomes during childhood. A high rate of mitochondrial DNA (mtDNA) instability was reported in the blood of HEU at birth. We aimed to explore the relationship between these health outcomes and mtDNA deletions over time in a case series of 24 HEU children. MtDNA instability was assessed by deep sequencing and analyzed by eKLIPse-v2 algorithm at three time points, namely birth, 1 year, and 6 years of age. Association between mtDNA deletion and health outcomes, including growth, clinical, and neurodevelopmental parameters, were explored using univariate statistical analyses and after stratification with relevant variables. HEU children were selected with an equal male:female ratio. An elevated number of mtDNA deletions and duplications events was observed at 7 days’ post-partum. Median heteroplasmy increased at one year of life and then returned to baseline by six years of age. The mtDNA instability was acquired and was not transmitted by the mother. No risk factors were significantly associated with mtDNA instability. In this small case series, we did not detect any association between any health outcome at 6 years and mtDNA instability measures. A significant effect modification of the association between the duration of maternal prophylaxis and child growth was observed after stratification with heteroplasmy rate. Genomic instability persists over time among HEU children but, despite its extension, stays subclinical at six years.

Result of purification for the Te do rice variety of Dien Bien province

Te do is a local rice variety planted in some districts of Dien Bien province (Tuan Giao, Muong Cha, Tua Chua...). This variety has high nutritional content, very good drought tolerance and is resistant to some major pests and diseases such as rice blasts, leaf blight, and brown planthopper. Te do is considered to have great potential in the set of varieties to be included in the agricultural production technology solutions to adapt to climate change, and at the same time increase economic value for growers in the northern mountainous region of Vietnam. The purification process of this rice variety was carried out from 2018 to 2020. From the results of monitoring in the field, 200 individuals (with the same flowering and maturing day) were selected for futher laboratory evaluation; then, 30 G1 lines with the same total growth duration and many similar traits were selected for the next growing season. After evaluation of 30 G1 lines, 10 satisfactory G1 lines were selected for the next growing season (G2). In the G2 generation, the best 6 qualified lines were selected from the 10 initial evaluation lines and the seeds of these 6 lines were mixed to get 400 kg which was tested and certified as registered seeds by the Center for Testing of Variety, the National Plant based on the national technical regulations on the quality of rice seeds.

Comparison of Short-Duration and Long-Duration Rice Cultivars Cultivated in Various Planting Densities

The selection of high-yielding, short-duration rice cultivars is essential for the double-rice cropping system. High hill density could be achieved with less labor under machine transplanted conditions. Therefore, dense planting is more practical for machine-transplanted rice. While few studies have been conducted to certify the feasibility of short-duration cultivar combined with dense planting in machine transplanted conditions. The current study was executed to determine the effects of dense planting on yield attributes and grain yield of short-duration cultivars under mechanically transplanted conditions. A field experiment comprises two treatments—i.e., the short-duration cultivar Lingliangyou104 cultivated at a high planting density (SDH) and the long-duration Taiyou390 cultivar cultivated at a low planting density (LDL)—were conducted in the 2018 and 2019 late seasons. The results showed that the SDH exhibited 17% and 19% higher panicle number in a unit, 26% and 24% higher spikelet filling, 8% and 8% higher grain weight, 21% and 11% higher harvest index, and consequently 12% and 4% higher grain yield and 13 and 15 days shortened growth duration compared to the LDL in the 2018 and 2019, respectively. The data revealed that the difference in grain yield between the SDH and LDL was mainly due to the higher harvest index and reasonable dry matter distribution of the SDH, which was conducive to improving yield components and increasing rice grain yield. As a result, short-duration rice cultivars combined with dense planting is a feasible strategy for improving the grain yield of mechanically transplanted late rice.

A transcriptional regulator that boosts grain yields and shortens the growth duration of rice.

Complex biological processes such as plant growth and development are often under the control of transcription factors that regulate the expression of large sets of genes and activate subordinate transcription factors in a cascade-like fashion. Here, by screening candidate photosynthesis-related transcription factors in rice, we identified a DREB (Dehydration Responsive Element Binding) family member, OsDREB1C, in which expression is induced by both light and low nitrogen status. We show that OsDREB1C drives functionally diverse transcriptional programs determining photosynthetic capacity, nitrogen utilization, and flowering time. Field trials with OsDREB1C-overexpressing rice revealed yield increases of 41.3 to 68.3% and, in addition, shortened growth duration, improved nitrogen use efficiency, and promoted efficient resource allocation, thus providing a strategy toward achieving much-needed increases in agricultural productivity.

Stubble height affects the grain yield of ratoon rice under rainfed conditions

Rice ratooning system is becoming an important rice planting system to ensure food security in China, and improvement of grain yield and yield stability has always been the primary goal in the development of ratoon rice. Here, field experiments were conducted in central China from 2020 to 2021 to explore the effects of water management (flooded vs rainfed) and stubble height (45, 20 and 0 cm; abbreviated as SH45, SH20 and SH0, respectively) on the yield performance of ratoon rice. The results demonstrated that water management during the main season had no effect on the grain yield of either main crop (MC) and ratoon crop (RC). However, rainfed treatment during the ratoon season significantly decreased the RC yield by 14.4% and 9.2% in 2020 and 2021, respectively. The reduction of stubble height prolonged the growth duration, decreased the panicle number, and increased the spikelets panicle−1, total spikelets and leaf area index. Compared with SH45, SH20 and SH0 increased the RC yield by 20.7% and 6.8% in 2020, respectively, whereas no significant difference in RC yield was observed among different stubble heights in 2021. Moreover, the grain yield of RC at low stubble heights was more susceptible to rainfed treatment. Specifically, rainfed treatment averagely decreased the RC yield by 4.9%, 12.7% and 17.2% at SH45, SH20 and SH0, respectively. The grain yield of RC was positively correlated with the panicle number, total spikelets and biomass accumulation, while low stubble heights, particularly SH20, had a greater magnitude of slope. Furthermore, panicle number exhibited stronger correlations with spikelets panicle−1 and biomass accumulation at low stubble heights. Overall, our results suggest that more attention should be paid to water management in the ratoon season, and increasing the panicle number is crucial to the improvement of yield and yield stability of RC at low stubble heights.

Reassessing the intrusive tempo and magma genesis of the late Variscan Aar batholith: U–Pb geochronology, trace element and initial Hf isotope composition of zircon

The Variscan orogeny was responsible for the formation of a significant volume of igneous basement throughout present-day Europe. Detailed understanding of these rocks has, however, been obfuscated by significant overprinting during younger geologic events. In order to better understand the formation of this basement, we present U–Pb dates, trace element concentrations and Hf isotope compositions of zircon from 17 intrusions of the Variscan Aar batholith, located in the Aar Massif, Central Alps, Switzerland. Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) was used to generate a large set of U–Pb dates, trace element and Hf isotope compositions on untreated zircon, as well as zircon pretreated by chemical abrasion. Furthermore, a subset of samples was also analyzed for high-precision U–Pb geochronology using chemical abrasion, isotope dilution, thermal ionization mass spectrometry (CA-ID-TIMS). The U–Pb dates of both dating techniques are significantly dispersed, indicating that they are influenced by multiple forms of complexity, including inheritance, domains of secondary alteration likely related to Alpine overprint or growth, decay damage related Pb-loss, and potentially protracted magmatic growth. Decay-damage related Pb-loss is likely a subordinate source of age scatter within the data, therefore chemical abrasion pretreatment is not capable of completely mitigating the observed analytical scatter. After rejection of outliers, the remaining data still exhibit excess scatter of several percent among 206Pb/238U dates in individual samples, however it is possible to interpret reasonable geologic ages from these data. These new U–Pb zircon age interpretations indicate the Aar batholith grew incrementally through four major magmatic pulses, which occurred at approximately 348, 333, 309 and 298 Ma. Based on the trace element and Hf isotope geochemistry, the melt source(s) of the Aar batholith evolved throughout the duration of batholith formation and growth. The transitioning from (i) melting of depleted mantle at 348 Ma during a stage of active continental arc magmatism (εHf = + 12 to + 10), (ii) melting of metasomatically enriched lithospheric mantle, possibly contaminated by crust during the 333 Ma pulse (εHf = − 10 to − 3), followed by (iii) an increasing incorporation of a juvenile mantle components during the 309 and 298 Ma pulses (εHf = − 3 to + 6). Finally, these new U–Pb ages yield a more detailed understanding of the Variscan Aar batholith by integrating the new detailed mapping of Aar Massif for the Geological Atlas of Switzerland, allowing for more accurate characterization and categorization of variably deformed heterogeneous intrusive bodies.

Riverscape heterogeneity in estimated Chinook Salmon emergence phenology and implications for size and growth

AbstractMany salmonid‐bearing rivers exhibit thermal and hydrologic heterogeneity at multiple spatial and temporal scales, but how this translates into spatiotemporal patterns of fry emergence is poorly understood. Understanding this variability is important because emergence timing determines the biophysical conditions fish first experience (e.g., temperature, flow, and food supply), thereby influencing growth opportunities and survival during this critical life stage. We predicted spring Chinook Salmon (Oncorhynchus tshawytscha) emergence phenology across four northeastern Oregon subbasins over 5–9 years using empirical spawning and temperature data. We then related interannual emergence timing estimates to juvenile salmon size and growth rates at consistent sampling locations. There were clear longitudinal patterns of predicted emergence timing in each subbasin: The shape of these patterns was consistent among years, but not among subbasins. In two subbasins, emergence occurred progressively later with distance upstream, whereas in the other two subbasins emergence was earliest at upstream sites. Within each year, median emergence dates among sites within each subbasin ranged between 44 and 58 days. This spatial variation was comparable to interannual variation, with median emergence dates for a given location in each subbasin ranging between 47 and 74 days among years. Contrary to our expectations, juvenile salmon were not larger in years with earlier emergence, owing to slower estimated spring and summer growth rates compared to years with later emergence. Despite large interannual variation in estimated emergence dates, these results suggest that other factors (e.g., stream flow, temperature, and density‐dependence) were more important than growth duration in determining juvenile salmon growth rates and size among years. We demonstrated considerable spatial and interannual variation in emergence phenology within these subbasins. Understanding how this variation translates to spatiotemporal patterns of juvenile salmon habitat use, growth, and survival has important implications for guiding restoration efforts and understanding how climate change may impact these populations.

Effect of rice cultivars, organic manures, and water management on methane emissions and grain yield

AbstractTo assess the effect of different organic manures and rice cultivars on methane emissions, a pot experiment was conducted at the Yezin Agricultural University, Nay Pyi Taw, Myanmar during the wet season of 2016. Organic manures (control, compost, and cow dung) and two rice cultivars (Manawthukha and IR 50) were tested. For both rice cultivars, high grain yield was observed in the control, and the minimum grain yield was observed in the cow dung treatment. The rate and cumulative CH4 emissions in Manawthukha were higher than those in IR 50, in accordance with the yield, because of the longer growth duration. Although not significant, the lowest methane emissions were observed in the cow dung manure treatment (0.808 g CH4 kg−1 soil) against the control (0.893 g CH4 kg−1 soil) and compost (0.951 g CH4 kg−1 soil) treatments. Based on these results, a field experiment was conducted at Madaya Township, Mandalay region, Myanmar during the dry and wet seasons of 2017 to determine the effects of water management and different rates of cow dung manure on methane emission and yield of IR 50. Higher methane emissions were recorded for continuous flooding (CF) than for alternative wetting and drying (AWD). In both seasons, higher grain yields (1.8% in dry and 7.6% in wet) were recorded for AWD than for CF. Higher methane emissions were recorded from OM3 and lower emissions from OM0 in both water management practices. In AWD, methane emissions were restricted under aerated soil conditions, although a higher amount of manure was added.

Rice Monitoring and Yield Estimation in Dumangas, Iloilo, Philippines Using Satellite Imagery

An agricultural monitoring procedure utilizing the combination of remotely sensed data, vegetation indices, ground truth information, and local knowledge on the phenology and development of rice, which is the staple crop produced in Dumangas, Iloilo, Philippines, was established and analyzed in this study. The areas with standing crops and their corresponding growth stage were reported for the 2nd and 3rd cropping of 2020. The spatio-temporal analysis determined that NDVI is directly correlated with the photosynthetic activity and development of the crop. Dry season cropping lasted from October to January, while the 3rd cropping lasted from February to April. The percentage of the rice areas planted per month were also studied and observed that the area spatially and numerically increased as farmers planted during the start of the season. The ground data from the 20 GCPs were compared with the Sentinel 2 NDVI. The phenological metrics for each point characterized the development of the crop. From the investigation, the municipality commonly used hybrid varieties, which have a growth duration of 85 to 100 days. The NDVI ranges were 0.163 to 0.309, 0.35 to 0.682, 0.535 to 0.671, and 0.235 to 0.533 for seedling, vegetative, reproductive, and ripening. APSIM was used for yield modeling of the cropping season 2019 and observed to have a good correlation during the wet season. Underestimation was detected for cropping seasons during times with limited rainfall. This study was beneficial for the LGU in crop estimation as it produced highly reliable spatial and temporal results.

Comprehensive Impacts of Climate Change on Rice Production and Adaptive Strategies in China.

The rice production system is one of the most climate change sensitive agro-ecosystems. This paper reviews the effects of current and future climate change on rice production in China. In recent decades, thermal resources have increased during the rice growing season, while solar radiation resources have decreased, and precipitation heterogeneity has increased. The increasing frequency of high-temperature stress, heavy rainfall, drought, and flood disasters may reduce the utilization efficiency of hydrothermal resources. Climate change, thus far, has resulted in a significant northward shift in the potential planting boundaries of single- and double-cropping rice production systems, which negatively affects the growth duration of single-, early-, and late-cropping rice. Studies based on statistical and process-based crop models show that climate change has affected rice production in China. The effects of climate change on the yield of single rice (SR), early rice (ER), and late rice (LR) were significant; however, the results of different methods and different rice growing areas were different to some extent. The trend of a longer growth period and higher yield of rice reflects the ability of China’s rice production system to adapt to climate change by adjusting planting regionalization and improving varieties and cultivation techniques. The results of the impact assessment under different climate scenarios indicated that the rice growth period would shorten and yield would decrease in the future. This means that climate change will seriously affect China’s rice production and food security. Further research requires a deeper understanding of abiotic stress physiology and its integration into ecophysiological models to reduce the uncertainty of impact assessment and expand the systematicness of impact assessment.

Rapid, paced metamorphism of blueschists (Syros, Greece) from laser-based zoned Lu-Hf garnet chronology and LA-ICPMS trace element mapping

Unravelling the timing and rate of subduction-zone metamorphism and H2O release requires linking time to the compositional changes of petrogenetic indicator minerals in blueschists and eclogites. Garnet is a key mineral in this regard, as it forms by, and records, H2O-releasing mineral reactions that can be linked to pressure and temperature conditions. These can be placed in time using chronology. Bulk-or multi-grain ages are the norm in garnet chronology. While these ages provide important and precise time constraints on reactions across both facies, the duration, rates and style of growth—crucial parameters in the petrological and geochemical evolution of subducting oceanic crust—remain unconstrained. Domain dating, i.e., dating of individual growth zones, is necessary to investigate these aspects, but is generally impeded in “common”-sized garnet grains due to sample size requirements. To overcome these limitations, we use a low-loss micro-sampling by laser cutting combined with Lu-Hf chronology. We used this approach to precisely date multiple growth zones in a 1-cm garnet grain from glaucophane-bearing micaceous schist of the Cycladic Blueschist Unit (CBU), Syros Island, Greece. The analysis was combined with major- and trace-element mapping (EPMA, LA-ICPMS) to investigate garnet petrogenesis. Garnet core and mantle zones are chemically comparable and identical in age within 0.1 Myr precision (2σ), indicating an initial growth pulse at 51.8 ± 0.1 Ma (MSWD = 1.13). The two rim zones, which are chemically distinct, were resolvably younger at 51.3 ± 0.2 Ma (MSWD = 0.67). Integrated with compositional data, these age constraints provide a time-resolved record of extremely fast, pulsed garnet growth and fluid-release reactions, such as chloritoid breakdown. These reactions can be considered near-instantaneous on subduction time scales, indicating that re-equilibration far outpaces changes in pressure and temperature conditions. The analysed sample is associated with the upper-subunit of the CBU with oceanic affinities, which does not share the last part of the prograde history with the rest of the CBU, i.e., the margin sub-unit. We interpret our sample as a sliver that became attached to the base of the ophiolitic sub-unit and was thrusted onto the lower margin unit at high-pressure. Beyond providing insights into the timing of subduction-zone processes, our new protocol for zoned garnet Lu-Hf geochronology of “common-sized” garnet opens new possibilities for constraining the causes and rates of garnet growth and the pace of tectonic processes in general.

Budget impact analysis of belumosudil for chronic graft-versus-host disease treatment in the United States

Aims To assess the impact of belumosudil on the cost of care in chronic graft-versus-host disease (cGVHD) patients who have failed at least two prior lines of systemic therapy using a budget impact model. Methods A budget impact model with a 5-year time horizon was constructed in Microsoft Excel. The base case model uses the US prevalence rate of 3 L/4L + cGVHD patients from literature and secondary sources, with the potential for user-defined inputs, including model perspectives. The model includes data for two perspectives: the national US population and a hypothetical US private payer health insurance plan with 10 million (Mil) members. Additional model inputs include market share of cGVHD treatments, their associated adverse event rates, and healthcare resource utilization. Results The potential annual budget impact for the US national and payer plans was evaluated for cGVHD patients. Based on belumosudil utilization increasing to 55% in 3 L and 4 L + by 2026, cost savings of ∼5.5% and 6.7% ($128.8 and $4.9 Mil USD) were observed from national and payer perspectives, respectively. Cost savings in 2026 were derived from fewer AEs ($108.4 and $3.9 Mil USD, for national and payer perspectives; e.g. neutropenia, and thrombocytopenia) and reduced HCRU ($65.1 and $2.3 Mil USD, for national and payer perspectives; e.g. emergency room visits, ICU stays, etc.). Limitations Results from the model were dependent on the available data inputs and assumptions. Real-world values may differ from the assumed performance of treatments, market growth, and treatment dosing and duration. Conclusion The model results suggest that the introduction of belumosudil to treat cGVHD would be associated with substantial cost savings when evaluating a scenario with versus without belumosudil from a US payer perspective.

Differential responses of soybean genotypes to off‐target dicamba damage

AbstractSince the commercialization and widespread adoption of dicamba‐tolerant (DT) soybean cultivars across the United States, numerous cases of off‐target damage to non‐DT soybean have been reported. Soybean is naturally highly sensitive to dicamba, a synthetic auxin herbicide. Previous studies have focused on understanding the impact of growth stage, dosage, frequency, and duration of dicamba exposure on the severity of symptomology and yield loss. To date, little research has investigated the effect of genetic components in the observed responses. Therefore, this study was conducted to estimate yield losses caused by prolonged off‐target dicamba exposure and to identify genotypes with varying responses to off‐target damage. A total of 553 soybean genotypes derived from 239 unique biparental populations were evaluated in nine environments over 3 yr. A yield penalty of 8.8% was observed for every increment in damage score on a 1–4 scale with losses as high as 40%. Although the interaction between damage and maturity group (MG) significantly affected yield, genotypes showing the most tolerance had similar yields independent of their MG. This indicated that natural tolerance to off‐target dicamba may be conferred by physiological mechanisms other than the length of the recovery window. Given the widespread adoption of DT systems and potential yield losses in non‐DT soybean genotypes, identification of non‐DT soybean genotypes with higher tolerance to off‐target dicamba may sustain and improve the production of other non‐DT herbicide soybean production systems, including the niche markets of organic and conventional soybean.

Yield Response of Spring Maize under Future Climate and the Effects of Adaptation Measures in Northeast China

Agriculture production has been found to be the most sensitive sector to climate change. Northeast China (NEC) is one of the world’s major regions for spring maize production and it has been affected by climate change due to increases in temperature and decreases in sunshine hours and precipitation levels over the past few decades. In this study, the CERES-Maize model-v4.7 was adopted to assess the impact of future climatic change on the yield of spring maize in NEC and the effect of adaptation measures in two future periods, the 2030s (2021 to 2040) and the 2050s (2041 to 2060) relative to the baseline (1986 to 2005) under RCP4.5 and RCP8.5 scenarios. The results showed that increased temperatures and the decreases in both the precipitation level and sunshine hours in the NEC at six representative sites in the 2030s and 2050s periods based on RCP4.5 and RCP8.5 climate scenarios would shorten the maize growth durations by (1–38 days) and this would result in a reduction in maize yield by (2.5–26.4%). Adaptation measures, including altered planting date, supplemental irrigation and use of cultivars with longer growth periods could offset some negative impacts of yield decrease in maize. For high-temperature-sensitive cultivars, the adoption of early planting, cultivar change and adding irrigation practices could lead to an increase in maize yield by 23.7–43.6% and these measures were shown to be effective adaptation options towards reducing yield loss from climate change. The simulation results exhibited the effective contribution of appropriate adaptation measures in eliminating the negative impact of future climate change on maize yield.

A protoxylem pathway to evolution of pith? An hypothesis based on the Early Devonian euphyllophyte Leptocentroxyla.

The Early Devonian (Emsian, 400-395 Ma) tracheophyte Leptocentroxyla tetrarcha Bickner et Tomescu emend. Tomescu et McQueen combines plesiomorphic Psilophyton-type tracheid thickenings with xylem architecture intermediate between the plesiomorphic basal euphyllophyte haplosteles and the complex actinosteles of Middle Devonian euphyllophytes. We document xylem development in Leptocentroxyla based on anatomy and explore its implications, which may provide a window into the evolution of pith. Leptocentroxyla is preserved by permineralization in the Battery Point Formation (Quebec, Canada). Serial sections obtained using the cellulose acetate peel technique document branching pattern, anatomy of trace divergence to appendages, protoxylem architecture, and variations in tracheid size and wall thickening patterns. Leptocentroxyla has opposite decussate pseudo-whorled branching and mesarch protoxylem, and represents the earliest instance of central histological differentiation in a euphyllophyte actinostele. Tracheids at the centre of xylem exhibit simplified Psilophyton-type wall thickenings and are similar in size (at the axis centre) or smaller than the surrounding metaxylem tracheids (at the centre of appendage traces). The position and developmental attributes of the simplified Psilophyton-type tracheids suggest they may have been generated by the protoxylem developmental pathway. This supports the delayed and shortened protoxylem differentiation hypothesis, which explains the evolution of pith by (1) delay in the onset of differentiation and lengthening of cell growth duration in a central protoxylem strand; and (2) shortening of the interval of differentiation of those tracheids, leading to progressive simplification (and eventual loss) of secondary wall thickenings, and replacement of tracheids with a central parenchymatous area. NAC domain transcription factors and their interactions with abscisic acid may have provided the regulatory substrate for the developmental changes that led to the evolution of pith. These could have been orchestrated by selective pressures associated with the expansion of early vascular plants into water-stresses upland environments.

Small-flowered clematis collections of the Stavropol Botanical Garden

Relevance. The biological features were studied, the average dates of the beginning, end and duration of the phenological phases of growth and development of species, forms and varieties of the genus Clematis (Clematis L.) were established. The assortment of small-flowered clematis for cultivation in the soil and climatic conditions of the Stavropol upland, characterized by high decorative properties, resistance to drought, pests and diseases, is highlighted.Methods. The object of research is small-flowered species, forms and varieties of the genus Clematis L., cultivated in the collection of the Stavropol Botanical Garden. The studies were conducted in 2012–2021 according to the methods of variety study and evaluation of the decorative qualities of clematis species and varieties.Results. The dates of the beginning and end of the growth of shoots are determined. According to the duration of shoot growth, all taxa are divided into groups: with a short growth period (38–51 days), medium (60–79 days); long (90–126 days). According to the timing of the beginning of flowering, the studied taxa are classified into five groups, most of them are included in the groups of early summer and summer flowering. According to the duration of flowering, three groups are distinguished — with short flowering, up to 30 days (C. jubata Bsch., C. recta L., C. recta f. atropurpurea, C. terniflora DC.); medium, from 41 to 60 days (С. fusca Turcz., C. ‘Bryzgi Morja’, C. integrifolia L., C. orientalis L., C. serratifolia Rehder, C. tangutica (Maxim.) Korsh., C. virginiana L., C. viticella L., C. viticella f. rosea); long-lasting, more than 60 days (C. ‘Fargesioides’, C. heracleifolia DC., C. hexapetala DC.).

Colloidal synthesis of CdTe nanoplatelets using various cadmium precursors

Two-dimensional (2D) CdTe nanoplatelets were synthesized using cadmium propionate, acetate and myristate precursors. Growth of nanoplatelets within the temperature range of 180–250 °C was monitored with optical absorption, PL spectroscopy and transmission electron microscopy. Continuous growth of NPLs was observed for hydrophobic propionate and myristate precursors at low temperatures, while in the presence of cadmium acetate Ostwald ripening occurs at high growth temperature. It is shown that zinc blende CdTe nanoplatelets with (00l) truncation axis grow by lateral expansion with oriented attachment mechanism. The presence of monomers is considered of major importance for oriented attachment. The growth conditions and duration time were optimized to provide homogeneous CdTe nanoplates.

Productivity and water use of ratoon rice cropping systems with water‐saving, drought‐resistant rice

AbstractWater‐saving, drought‐resistant rice (WDR) (Oryza sativa L.) is a type of new rice cultivars with high drought resistance and low water consumption in the production phase. Ratoon rice cropping is regarded as a resource‐efficient rice production system with low cost and high profit. The development of ratoon rice system with WDR is conducive to the sustainable production of rice and the expansion of rice plantation; however, no such attempt has been made. In this study, a field experiment was conducted for 2 yr to evaluate the feasibility of developing new ratoon rice cropping systems using WDR compared with using common lowland rice (CLR). The productivity, regenerative capacity, and water use efficiency (WUE) were investigated in the water‐saving cultivation system using two WDR cultivars—Jieyou 652 and Jieyou 804—and in the conventional flooding cultivation system using the CLR cultivar Fengliangyouxiang 1. The irrigation WUE for the WDR systems was 89.8–214.8% and 243.4–765.6% higher than for the CLR system in the main and ratoon cropping seasons, respectively. The grain yield was not significantly different in the main cropping season between the WDR and CLR systems; nevertheless, it was lower in the WDR systems because of shorter growth duration and smaller panicles in the ratoon season. Higher accumulations of dry matter (DM), nonstructural carbohydrates (NSCs), and nitrogen in the stubble of main‐season crops is helpful to the promotion of regenerative capacity of WDR in the ratoon season.