Early Maturation Research Articles

Progenesis in dicyemids

AbstractDicyemids (Phylum Dicyemida) are the most common and characteristic endosymbiont living in the renal sac of benthic cephalopod molluscs. Precocious development of a hermaphroditic gonad occurs in the larvae and smaller juveniles of 40 dicyemid species from 17 cephalopod species so far and is the usual phenomenon in dicyemids. Based on the developmental and morphological features of precocious individuals, progenesis (a form of heterochrony) is the appropriate term for such precocious development. In general, progenetic individuals have much lower fecundity than normal ones because of their smaller body size, and therefore, it appears to be a disadvantageous reproductive trait. Nonetheless, the number of progenetic individuals consists of 30%–50% of the population, a relatively large proportion suggesting that the presence of progenetic individuals probably plays an important role in life history strategy. Precocious development significantly reduces growth time and enables early maturation. Progenetic individuals are common in short‐living cephalopod species, in which precocious development seems appropriate for dicyemids, enabling fast larval release before the end of the host's life span.

Talk it out or tuck it away: The contribution of maternal socialization of coping to depression in youth with early pubertal maturation.

Theory and research highlight the mismatch between puberty-associated challenges and personal coping resources among youth with early actual or perceived pubertal timing. This study (N = 167; Mage = 12.41 years; 51.5% female; 77.8% White American) examined whether coping resources provided by mothers (maternal socialization of coping) exert protective or exacerbating effects on risk for depression among early-maturing youth. Results revealed that earlier perceived timing predicted higher subsequent depressive symptoms in girls with low (B = .40, SE = .15) but not high (B = -.08, SE = .17) levels of engagement coping suggestions, whereas earlier perceived timing predicted higher subsequent depressive symptoms in boys with high (B = .40, SE = .17) but not low (B = -.12, SE = .15) levels of engagement coping suggestions. These findings build on prior theory and research by highlighting that maternal coping suggestions may mitigate or enhance depression risk in youth who perceive themselves as early maturers; the differential effects in girls and boys suggest that the impact of these suggestions may depend on whether they are in line with gender-specific norms for coping. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Phenological Variation in Chickpea (Cicer arietinum L.) Varieties through Foliar Application of Cytokinin Analogs and Nutrients under Water Deficit Stress

Chickpea (Cicer arietinum L.), a rainfed crop predominantly grown in temperate and subtropical climates, faces significant challenges in production due to terminal drought stress impacting various phenological stages. This study addresses the challenges posed by terminal drought stress on the phenological stage of chickpea varieties viz., JG 36 and JG 14. The experiment was conducted during the Rabi seasons of 2021-2022 and 2022-2023 at the Experimental Research Farm, Seed Technology Research Unit, JNKVV, Jabalpur (M.P), using a split-split plot design with three replications. This research also investigates the impact of foliar applications of cytokinin analogs viz., Thiourea, Thidiazuron, and Benzyladenine and nutrients viz., ZnSO4 and KCl on chickpea under water deficit stress conditions. The results revealed significant differences in days to pod formation, seed formation, physiological maturity, and harvest maturity among the irrigation levels, varieties, and foliar spray of plant growth regulators and nutrients. Under different irrigation levels, D1 (Irrigation at 30 DAS and flower initiation) exhibited delayed phenological stages of the crop, while D2 (Drought stress at flowering up to physiological maturity) showed an early onset of all the phenological stages. Under water deficit conditions, JG 14 exhibited accelerated maturity beyond its typical early maturation in comparison to well-watered conditions, highlighting the impact of environmental stress on varietal responses. With respect to the application of plant growth regulators and nutrients, treatment T12 (TDZ @ 10 ppm + 1% KCl) significantly delayed pod and seed formation, as well as physiological and harvest maturity as compared to untreated control (T1). Foliar application of TDZ @ 10 ppm + 1% KCl (T12) enhanced seed filling duration by 2.59 days compared to the untreated control. Further investigations are needed to identify the impact of Thidiazuron and KCl in enhancing seed yield and seed weight of chickpea under optimal and sub-optimal soil water conditions, to provide recommendations for chickpea growers.

Raman developmental markers in root cell walls are associated with lodging tendency in tef

Main conclusionUsing Raman micro-spectroscopy on tef roots, we could monitor cell wall maturation in lines with varied genetic lodging tendency. We describe the developing cell wall composition in root endodermis and cylinder tissue.Tef [Eragrostis tef (Zucc.) Trotter] is an important staple crop in Ethiopia and Eritrea, producing gluten-free and protein-rich grains. However, this crop is not adapted to modern farming practices due to high lodging susceptibility, which prevents the application of mechanical harvest. Lodging describes the displacement of roots (root lodging) or fracture of culms (stem lodging), forcing plants to bend or fall from their vertical position, causing significant yield losses. In this study, we aimed to understand the microstructural properties of crown roots, underlining tef tolerance/susceptibility to lodging. We analyzed plants at 5 and 10 weeks after emergence and compared trellised to lodged plants. Root cross sections from different tef genotypes were characterized by scanning electron microscopy, micro-computed tomography, and Raman micro-spectroscopy. Lodging susceptible genotypes exhibited early tissue maturation, including developed aerenchyma, intensive lignification, and lignin with high levels of crosslinks. A comparison between trellised and lodged plants suggested that lodging itself does not affect the histology of root tissue. Furthermore, cell wall composition along plant maturation was typical to each of the tested genotypes independently of trellising. Our results suggest that it is possible to select lines that exhibit slow maturation of crown roots. Such lines are predicted to show reduction in lodging and facilitate mechanical harvest.

Analysis of genes specific to the early maturation stage of Sesamum indicum seeds by subtraction method*,*.

The mechanisms regulating the content ratio of unsaturated fatty acid in sesame oil need to be clarified in order to breed novel varieties with high contents of unsaturated fatty acids. Full-length cDNA libraries prepared from sesame seeds 1 to 3 weeks after flowering were subtracted with cDNAs from plantlets of 4 weeks after germination. A total of 1545 cDNA clones was sequenced. The functions of novel genes expressed specifically during the early maturation of sesame seeds were investigated by the transformation of Arabidopsis thaliana. Thirteen genes for a transcription factor were identified, four of which were involved in ethylene signaling. Fifty-nine genes, including those for the aquaporin-like protein and ethylene response factor, were analyzed by overexpression in A. thaliana. The overexpression of novel genes and the aquaporin-like protein gene in A. thaliana increased the content of unsaturated fatty acids. The localization of these products was investigated by the induction of the expression vectors for the GFP fusion protein into onion epidermal cells and sesame root cells with a particle gun. As a result, two cDNA clones were identified as good candidate genes to clarify the regulation in the yield and the ratio of unsaturated fatty acids in sesame seeds. Sein60414 (Accession No. LC603128), an intrinsic membrane protein, may be involved in the increase of unsaturated fatty acids, and Sein61074 (Accession No. LC709278) MAP3K δ-1 protein kinase in the regulation of the total ratio of unsaturated fatty acids in sesame seeds.

Floral-promoting GmFT homologs trigger photoperiodic after-effects: An important mechanism for early-maturing soybean varieties to regulate reproductive development and adapt to high latitudes.

Soybean (Glycine max) is a typical short-day plant, but has been widely cultivated in high-latitude long-day (LD) regions because of the development of early-maturing genotypes which are photoperiod-insensitive. However, some early-maturing varieties exhibit significant responses to maturity under different daylengths but not for flowering, depicting an evident photoperiodic after-effect, a poorly understood mechanism. In this study, we investigated the postflowering responses of 11 early-maturing soybean varieties to various preflowering photoperiodic treatments. We confirmed that preflowering SD conditions greatly promoted maturity and other postflowering developmental stages. Soybean homologs of FLOWERING LOCUS T (FT), including GmFT2a, GmFT3a, GmFT3band GmFT5a, were highly accumulated in leaves under preflowering SD treatment. More importantly, they maintained a high expression level after flowering even under LD conditions. E1 RNAi and GmFT2a overexpression lines showed extremely early maturity regardless of preflowering SD and LD treatments due to constitutively high levels of floral-promoting GmFT homolog expression throughout their life cycle. Collectively, our data indicate that high and stable expression of floral-promoting GmFT homologs play key roles in the maintenance of photoperiodic induction to promote postflowering reproductive development, which confers early-maturing varieties with appropriate vegetative growth and shortened reproductive growth periods for adaptation to high latitudes.

Smoltification, seawater performance, and maturation in Atlantic salmon (Salmo salar) fed different fat levels

IntroductionThe use of recirculating aquaculture systems (RAS) to produce Atlantic salmon smolts has resulted in exceptionally high fish growth rates. However, there are potential negative trade-offs between fast growth and key physiological processes, such as inadequate smoltification and early sexual maturation, which can both be linked to body energy reserves.MethodsThis study determined the effect of i) dietary fat levels on Atlantic salmon whole-body fat and fatty acids composition, growth performance and smoltification and ii) a previous dietary regime on seawater growth performance and male early sexual maturation. In freshwater RAS, salmon parr (~19g) were fed 3 fat levels (20, 24, and 28%) over a 14-week period at 12°C. Subsequently, in seawater flow-through systems, smolt (~96g) were fed a control diet (26%) for 12 weeks at 2 temperatures (12 and 16°C).ResultsDietary fat levels resulted in differences in k-factor, fish whole-body fat and fatty acids composition; the low fat diet resulted in fish with a 23% lower whole-body fat when compared to the other two dietary groups at the end of the freshwater phase. These differences in whole-body fat faded at the end of the seawater phase. During the freshwater phase, all three feeds resulted in a comparable growth performance and smoltification indicator values, including k-factor, gill Na+, K+-ATPase, blood serum chloride and smolt index score. In contrast, water temperature resulted in fish body weight differences, where groups reared at 16°C were larger than those reared at 12°C. Nevertheless, both temperature regimes supported a similar thermal growth coefficient. Smolts grown at 16°C showed a higher level of the sex steroids androstenedione compared to those at 12°C. However, 11-ketotestosterone and testosterone levels did not differ despite a trend for higher levels at 16°C. Furthermore, testis histology at the final sampling indicated that some individuals showed initial signs of maturation (stage 3).DiscussionIn conclusion, varying dietary fat levels (20 - 28%) during the freshwater phase did not influence smoltification or male early sexual maturation during the subsequent grow-out phase. However, a temperature increase from 12 to 16°C resulted in larger fish and appeared to stimulate early male maturation in some fish individuals.

A comprehensive review on mutation breeding milestones in cereals: Conventional to advanced molecular approaches to achieve sustainable goals in trait improvement

The grass family includes the annual common grasses known as cereals. The 5 main types of cereals are rice, wheat, barley, rye and oats. As a result of their high vitamin (20-80%) and fiber content (90%), these grains can help treat conditions like type II diabetes, complex metabolic syndrome, obesity, gastrointestinal disorders, and high cholesterol. Cereals have inspired a long history of research into their genetics, development, and evolution due to their significance in both economic and scientific terms. They need to be improved because they play a big part in global food production and crop quality is declining. The crop improvement can be done by incorporating desired features from non-adapted landraces/wild resources. That induced mutagenesis has made a significant contribution to crop improvement initiatives by producing mutant varieties with better and desired genetic modifications in the crop plants mainly in agronomically significant features. The mutants produced by the induction of physical and chemical mutagens were highly useful. The notable traits obtained by the induced mutations are semidwarfness and early maturity in rice varieties, disease resistance in barley, salinity, and drought tolerance in wheat, and lodging and disease resistance in oat and rye. In this review, we focused on identifying and developing elite mutants, their genetic function, and their utilization in future breeding programs for various traits in cereal crops.

Effect of Socio-economic Factors on Level of use of Improved Maize Varieties in Bungoma County, Kenya

Maize is Kenya’s primary staple food, where 75% of producers are smallholder farmers. Maize consumption exceeds production with imports bridging the gap. Improved maize varieties have been adopted by smallholder farmers but the deficit gap still exists. The study’s objective was to determine factors influencing the adoption intensity of improved maize varieties in Bungoma County. Primary data was collected from 500 smallholder farmers using a structured questionnaire. Data was analysed using the Statistical Package for Social Sciences Version 27 software and a fractional logit model applied. Factors influencing adoption intensity of improved maize varieties were personal characteristics of the farmer (age, and household size), institutional factors (extension service) and varietal factors (early maturity, pest and disease resistance, drought resistance). Age, household size and extension services reduced the intensity of adoption, while varietal factors increased the intensity of adoption of improved maize varieties. The recommendations from the study is that even if the extension agents discouraged increased acreage under maize, they need to address and manage risk aversion among the old farmers through providing information and support groups. Counties should nurture a strong research-inkage with researchers to demonstrate demonstrate technology benefits.

Metabolome and Transcriptome Analysis Provide Insights into Flower Bud Color Variation in the Adaptation to UV-B Radiation of Litchi

Flower color variations have increasingly been recognized as playing an important role in the adaptation to UV-B radiation; however, the underlying mechanism is poorly understood in perennial fruit trees. Litchi is an important fruit tree, and extremely early maturing (EEM) and middle-to-late-maturing (MLM) cultivars that originated from regions with high and low UV-B radiation have dark brown and light yellow flower buds, respectively, while their hybrid early-maturing (EM) cultivars have an intermediate brown flower bud. This study comprehensively analyzed the metabolome and transcriptome of flower buds of litchi EEM, EM and MLM cultivars to explore the mechanism underlying flower color variation during the adaptation to UV-B radiation for the first time. Metabolomic analysis identified 72 flavonoids in litchi flower buds, among which a higher accumulation of flavonol glycosides was responsible for darker flower buds of EEM cultivars. And transcriptome analysis revealed key structural genes, including LcCHI, LcFLS and seven UGTs, together with two transcription factors (LcMYB12 and LcMYB111), which could be directly up-regulated by UV-B radiation, playing critical roles in regulating the differential accumulation of flavonol glycosides. These results provide new insights into the molecular mechanism underlying adaptation to UV-B radiation and provide a genetic basis for future breeding of stress-tolerant cultivars of litchi.

Evaluation of Different Genotypes of Ridge Gourd for Better Growth, Yield and Quality under Prayagraj Agro-Climatic Conditions

Ridge gourd, scientifically known as Luffa acutangula, is a tropical vine that belongs to the Cucurbitaceae family. It is commonly grown for its young and tender fruits, which are used as a vegetable in cooking. It is known by various names, including Kalitori, angled gourd, angled loofah, silky gourd, and ribbed gourd. Ridge gourd has a chromosome number of 2n = 26. This versatile vegetable can be incorporated into a wide range of dishes, such as stir-fries, curries, soups, and stews, thanks to its mild and slightly sweet flavor. In the Kharif season of 2022. a study was conducted at the Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture Technology and Sciences in Prayagraj, Uttar Pradesh, to assess the performance of different ridge gourd genotypes under the local agro-climatic conditions. The experiment followed a Randomized Block Design and involved nine genotypes with three replications each. The genotypes included G1 (IET 2021/RIGHYB-1), G2 (IET 2021/RIGHYB-2), G3 (IET 2021/RIGHYB-3), G4 (IET 2021/RIGHYB-4), G5 (IET 2021/RIGHYB-5), G6 (IET 2021/RIGHYB-6), G7 (IET 2021/RIGHYB-7), G8 (Dharidar-8), and G9 (Jaipuri Long-9).Based on the results of the experiment, it was determined that the genotype IET 2021/RIGHYB-5 exhibited the best performance in terms of growth parameters, such as vine length (222.10 cm) and early maturity, with the first fruit ready for picking in 60.00 days. It also excelled in yield parameters, including fruit length (25.03 cm), fruit diameter (5.65 cm), and fruit yield per plant (1528.31 g/plant). Additionally, IET 2021/RIGHYB-7 demonstrated outstanding performance in quality parameters, including Total Soluble Solids (TSS) at 4.23°Brix and Vitamin C content at 2.05 mg/100g.

Genome-wide analysis and expression of the aquaporin gene family in Avena sativa L.

Oat (Avena sativa L.) belongs to the early maturity grass subfamily of the Gramineae subfamily oats (Avena) and has excellent characteristics, such as tolerance to barrenness, salt, cold, and drought. Aquaporin (AQP) proteins belong to the major intrinsic protein (MIP) superfamily, are widely involved in plant growth and development, and play an important role in abiotic stress responses. To date, previous studies have not identified or analyzed the AsAQP gene family system, and functional studies of oat AQP genes in response to drought, cold, and salt stress have not been performed. In this study, AQP genes (AsAQP) were identified from the oat genome, and various bioinformatics data on the AQP gene family, gene structure, gene replication, promoters and regulatory networks were analyzed. Quantitative real-time PCR technology was used to verify the expression patterns of the AQP gene family in different oat tissues under different abiotic stresses. In this study, a total of 45 AQP genes (AsAQP) were identified from the oat reference genome. According to a phylogenetic analysis, 45 AsAQP were divided into 4 subfamilies (PIP, SIP, NIP, and TIP). Among the 45 AsAQP, 23 proteins had interactions, and among these, 5AG0000633.1 had the largest number of interacting proteins. The 20 AsAQP genes were expressed in all tissues, and their expression varied greatly among different tissues and organs. All 20 AsAQP genes responded to salt, drought and cold stress. The NIP subfamily 6Ag0000836.1 gene was significantly upregulated under different abiotic stresses and could be further verified as a key candidate gene. The findings of this study provide a comprehensive list of members and their sequence characteristics of the AsAQP protein family, laying a solid theoretical foundation for further functional analysis of AsAQP in oats. This research also offers valuable reference for the creation of stress-tolerant oat varieties through genetic engineering techniques.

Gradually decreasing daylength after smoltification induced by “winter signal“ reduced sexual maturation in male Atlantic salmon

IntroductionMaturation in seawater-adapted (smoltified) male Atlantic salmon is undesirable yet frequently reported in fish weighing up to 1 kg reared under intensive conditions in land-based facilities. Although the photoperiod regulates both smoltification and maturation, the optimal post-smoltification regimen for the prevention of maturation is unclear.MethodsIn this study, mixed-sex Atlantic salmon weighing 95 g were exposed to three different photoperiod regimes: continuous daylength, gradually decreasing daylength, and short-to-long daylength after the induction of smoltification by the “winter signal” (12 h:12 h light:dark). Fish were maintained under these conditions in triplicate for 18 weeks in a brackish water flow-through system at 12°C and with a salinity of 20 ppt. This initial phase was followed by a grow-out period (1 kg–2.5 kg) in seawater (32-ppt salinity) at 13°C for 11 weeks, with exposure to decreasing daylength. Throughout the 29-week study, body condition, gonad development, and morphological traits were assessed. Additionally, during exposure to brackish water, serum 11-ketotestosterone (11-KT) levels were quantified, and the testes were examined histologically. Upon termination of the study, the maturation rate was determined.ResultsThis study exclusively detected maturation among male salmon. Under continuous light exposure, the number of fish initiating maturity steadily increased from week 8 and continued to increase in the subsequent samplings. In the short-to-long daylength group, a subset of male fish showed elevated 11-KT levels at week 14, although their gonadal development and morphological changes were not evident until week 18. Male fish exposed to decreasing daylength showed no substantial increase in 11-KT levels, although a few fish exhibited advanced gonad development by week 18. At the end of the trial, markedly lower percentages of maturing and fully mature male fish were observed among those fish previously exposed to decreasing daylength. The maturation rates at study termination were 44.4% for the short-to-long daylength group, 29.4% for the continuous daylength group, and 4.3% for the decreasing daylength group.DiscussionThese results show that photoperiod can be utilized to regulate maturation in male Atlantic salmon. In addition, decreasing the photoperiod after smoltification seems to limit early sexual maturation without compromising body size development. Thus, decreasing the photoperiod could be utilized to limit maturation in the production of post-smolt salmon or salmon in land-based facilities.

Water use characteristics of an early and late maturing maize hybrid using stable isotopes

AbstractWater requirements of early‐maturing (EM) maize hybrids might be lower than those of late‐maturing (LM) maize hybrids. This study aimed to analyze the effects of different irrigation management on grain yield (GY), water uptake patterns, evaporation (E), and transpiration (T) of two maize hybrids differing in maturity via stable isotope method. The field experiment with 36 lysimeters (4‐m wide × 4‐m long) under rain‐shelters was conducted with an EM (DH518) and a mid‐maturing and LM (DH605) hybrid with three replicates from 2021 to 2022. Maize plants were grown under three irrigation amounts (W1, W2, and W3 were irrigated to maintain soil moisture at 45%, 60%, and 75% of field capacity, respectively) by flood irrigation (FI) and drip irrigation (DI) under rain‐out shelters. Results showed that GY and evapotranspiration (ET) of EM were 8% and 12% lower, while the crop water productivity (CWP) was 6% higher than that of LM. Water uptake of both hybrids occurred mainly within 0‐ to 60‐cm soil layer during the vegetative stage. Water uptake of both hybrids occurred mainly within 0‐ to 60‐cm soil layer during the vegetative stage. Summer maize under FI absorbed more water from the deep soil layer than DI in the late growth stage. Compared with LM, the water absorption depth of EM became shallower in the late growth stage. Water uptake of maize was mainly from the deeper soil under water stress conditions. E of total ET accounts for 43% under DI and 57% under FI; GY and CWP were 22% and 51% higher than those of FI. Together with choosing EM hybrids, optimization of water management with DIW3 could achieve higher GY and CWP. The optimization of irrigation method and hybrids could provide a reference for local farmers to improve GY and CWP.

Transient suppression of Wnt signaling in poor-quality buffalo oocytes improves their developmental competence.

One of the most evolutionary conserved communication systems, the Wnt signaling pathway is a major gene regulatory pathway that affects the developmental competence of oocytes and regulates most embryonic developmental processes. The present study was undertaken to modulate the canonical Wnt (Wingless/integration) signaling pathway in the poor-quality (colorless cytoplasm after Brilliant Cresyl Blue staining, BCB-) buffalo cumulus-oocyte complexes (COCs) to improve their in vitro maturation (IVM) and embryo production (IVEP) rates. The expression of key Wnt pathway genes was initially assessed in the good (blue cytoplasm after Brilliant Cresyl Blue staining, BCB+) and poor quality (BCB-) buffalo COCs to establish a differential activity of the Wnt pathway. The BCB- COCs were supplemented with the Wnt pathway inhibitor, Dickkopf-related protein 1 (DKK1) and later subjected to IVM and IVEP along with the BCB+ and BCB- controls. The cumulus expansion index (CEI), rate of nuclear maturation (mean percentage of oocytes in the MII stage) and embryo production, and the expression of developmentally important genes were evaluated to assess the effect of Wnt pathway inhibition on the development competence of these poor-quality oocytes. The Wnt pathway genes exhibited a significantly higher expression (p < 0.05) in the poor-quality BCB- oocytes compared to the good-quality BCB+ oocytes during the early maturation stages. The supplementation of BCB- COCs with 100 ng/mL DKK1 effectively inhibited the expression of the key mediators of the Wnt pathway (β-catenin and dishevelled homolog 1, DVL1). DKK1 supplemented BCB- COCs exhibited significantly improved cytoplasmic and nuclear maturation indices, development rates and significantly elevated expression (p < 0.05) of genes implicated in germinal vesicle breakdown (GVBD) and embryonic genome activation (EGA) vis-à-vis BCB- control COCs. These data indicate that inhibition of the Wnt pathway during the initial course of oocyte maturation can improve the development competence of poor-quality buffalo oocytes.

Who Reaches the NHL? A 20-Year Retrospective Analysis of Junior and Adult Ice Hockey Success in Relation to Biological Maturation in Male Swedish Players

ObjectivesThis study investigated the relationship between biological maturation and success in adolescence and adulthood in male Swedish ice hockey players.MethodsAnthropometric records of players in certified ice hockey high schools between 1998 and 2017 were retrieved (n = 4787). The database was complemented with records of Swedish junior national teams (U16, U18, U20) and National Hockey League (NHL) appearances. Biological maturation was recorded as a percentage of adult height (%AH), and selection probabilities were estimated using a generalised linear mixed effects model. Biological age was determined by comparing players with age-matched growth reference values. Categories of %AH, standard deviation z-scores and biological age offset describing early, on-time and late maturation were created.ResultsA total of 217 players had played on the U16 national team (junior success), and 96 reached the NHL (adult success). The difference [95% confidence interval (CI)] in baseline %AH between players with junior versus adult success was − 0.75 (− 0.39, − 1.11). Looking at age-offset categories in junior success, 30% of players were early maturing and 19% of players were late maturing, showing a bias towards early maturation (p < 0.01). In contrast, more late-maturing players (40%) achieved adult success than early-maturing players (25%), and NHL players had significantly later maturation [%AH: − 0.48 (− 0.80, − 0.16)] than non-NHL players.ConclusionThis unique 20-year analysis shows that junior success in male ice hockey is positively related to early maturation, while adult success is inversely related to advanced maturation. Ice hockey organisations should implement maturation assessments to optimise the development of both late- and early-matured players.

Role of Pubertal Timing and Perceived Parental Attachment in Internalizing Problem Behaviours Among Adolescents.

Adolescents need supportive social institutions to help them deal effectively with the demands of pubertal changes accompanied by new social roles, reducing their susceptibility to problem behaviors. Considering this, it will be investigated how internalizing problem behaviors in teenagers is affected by the interaction between pubertal timing and perceived parental attachment. For this, cross-sectional data from 772 adolescents with ages ranging from 11 to 15years old was used. Regression analyses showed early maturing adolescents with insecure perceived parental attachments had higher levels of depression and anxiety than their early, on-time, and late maturing counterparts with secure perceived parental attachments. This finding supports the contextual amplification model, as the detrimental consequences of early maturation are impacted by difficult parent-adolescent relationships.

Response of soil microbial properties in the life cycle of potatoes to organic substitution regimes in North China

Organic substitution regimes (OSR) can improve soil microbial properties in crop production. However, the dynamic responses of soil microbial flora and its driving factors in crop growth periods under OSR are still unclear. Here, a 2-year fertilizer field trial was conducted to explore the response of soil chemistry and microbial properties to OSR in the life cycle of potatoes (Solanum tuberosum L.) in North China. The fertilization treatment included only mineral fertilizer (ConN), substitution of 30% mineral N with organic N (M30), and substitution of 60% mineral N with organic N (M60); soil samples were collected and analyzed in the early flowering period (EP), flowering period (MP), and maturity period (LP) of potatoes. As the potato growth period progressed, M30 and M60 increased soil organic carbon (SOC) compared with ConN. Soil total nitrogen (pH) increased (decreased) under M60, while soil available potassium was similar across three treatments. Compared with ConN, soil bacterial Chao, Shannon, and PD indexes significantly increased under M30 and M60 in MP and LP, and the fungal Shannon index increased in LP. Soil bacterial and fungal community structures under M30 and M60 were only significantly separated from ConN in MP. The bacterial communities of dominant phyla or genera responded more sensitively to the fertilization regimes than the flora of fungi, and the changes in the flora mainly occur in EP and MP. Redundancy analysis revealed that SOC and available phosphorus were highly correlated with soil microbial community compositions. Compared with ConN, soil microbial network complexity and fungal network robustness were higher under M30 and M60, while bacterial network robustness showed the opposite trend. Partial least squares pathway modeling showed that the conversion in the fertilization system or growth period had a direct positive effect on the C/N-cycling function of soil bacteria, but not on the C-degradation function of fungi. Our research has important theoretical implications for the development of microbial fertilizers and fertilization management in different potato growth periods.

EUCALYPTUS ‘GG 100’ RESPONSE TO SIMULATED DRIFT OF ORTHOSULFAMURON

Plant growth regulators and low doses of herbicides are used in some crops in order to achieve satisfactory yields. They can cause morphological or physiological changes in plants qualitatively or quantitatively, such as in the inhibition and delay of vegetative development, in the early maturation or in sugar accumulation. The application of these products through spraying aims to reach the target crop. However, some neighboring crops may be contaminated through drift. The present study aims to evaluate the effects of simulated drift of orthosulfamuron on the initial growth of Eucalyptus urophylla seedlings, clone GG 100. The experiment was installed in pots of 5 L capacity in a completely randomized design, with nine treatments and four replicates. The treatments consisted of the following nine increasing doses of orthosulfamuron ripener: 0; 1.19; 2.39; 4.78; 9.56; 19.12; 38.25; 76.5; and 127.5 g a.i. ha-1. The height of the eucalyptus plants were evaluated at 0, 14, 28, 42, and 63 days after application (DAA). At 63 DAA, in the end of the experiment, the stem diameter, leaf area, and the dry matter of leaves, stems, and roots were evaluated. In conclusion, there were no deleterious effects of the drift of orthosulfamuron up to the dose of 127.5 g a.i. ha-1 on the development and growth of E.urophylla seedlings, clone GG 100, up to 63 days after application.

Annual reproductive cycle of Chinese sleeper Perccottus glenii, Dybowski, 1877 (Teleostei: Gobiiformes: Odontobutidae) an invasive fish inhabiting Central Europe

Chinese sleeper is an invasive species from South Asia inhabiting Eastern and Central Europe. So far, no detailed analysis of the reproductive cycle of Chinese sleepers has been conducted. The aim of the study was to describe the reproductive cycle of Chinese sleepers in the Wilanówka River, Vistula tributary (Poland, Central Europe). Fish morphometric data, age, gonadal maturity, and absolute and relative fecundity of females were analysed. A standard paraffin technique and six-stage scales were used to assess the gonad development and maturation in both sexes. The age of the studied fish ranged from 0+ to 6+.The female-to-male ratio was 1:1. Females and males mature at age 1+.The smallest female and male reaching maturity were 3.8 and 3.7 cm long, respectively. An extended spawning season from the beginning of April to mid-September was determined based on gonadal maturity analysis. The mean absolute fecundity was 2,971 (180–19,656) oocytes. The male reproductive system comprises paired testis (spermatogenic region, blackish color) and paired testicular gland (secretory region, whitish color). In both regions, seasonal changes were observed. Male gonads during winter had completed spermatogenesis, and the lobules were filled with spermatozoa. Very fast spermatogenesis and overlapping of reproductive cycles have been observed in Chinese sleeper males. Almost all year round testis contains spermatozoa. In the new habitat examined, this species was characterized by earlier maturation and longer reproduction season, compared to the native habitat and other native species of the examined area. Moreover, high female fecundity, multiple spawning, and lower investment in the development of gonads in males allow maintaining vitality and protecting the nest, contribute to the species competitiveness and successful colonization of new areas.