Reproductive Period Research Articles

Sleep: Giving it up to get it on

A new study presents evidence of sex-related sleep reduction in males of two marsupial mice species but not in females. The growing experimental data suggest that seasonal sleep reduction, linked to migrations and reproductive periods, is common among animals.

Sustainable animal agriculture in the United States and the implication in Republic of Korea.

Agriculture has played a significant role in the national economy, contributing to food security, driving economic growth, and safeguarding the dietary habits of the population. Korean agriculture has been compelled to focus on intensive farming due to its limited cultivation area, excessive input costs, and the limitations of agricultural mechanization. In the Republic of Korea (R.O.K), the concept of environmentally friendly animal agriculture began to be introduced in the early 2000s. This concept ultimately aims to cultivate sustainable animal agriculture (SAA) through environmentally friendly production practices, ensuring the healthy rearing of animals to supply safe animal products. Despite the government's efforts, there are still significant challenges in implementing environmentally friendly agriculture and SAA in the R.O.K. Therefore, the objective of this review is to establish the direction that the animal agriculture sector should take in the era of climate crisis, and to develop effective strategies for SAA tailored to the current situation in the R.O.K by examining the trends in SAA in the U.S. The animal agriculture sector in the U.S. has been working towards creating a SAA system where humans, animals, and the environment can coexist through government initiatives, industry research, technological support, and individual efforts. Efforts have been made to reduce emissions like carbon, and improve factors affecting the environment such as the carbon footprint, odor, and greenhouse gases associated with animal agriculture processes for animals such as cattle and pigs. The transition of the U.S. towards SAA appears to be driven by both external goals related to addressing climate change and the primary objectives of responding to the demand for safe animal products, expanding consumption, and securing competitiveness in overseas export markets. The demand for animal welfare, organic animal products, and processed goods has been increasing in the U.S. consumer market. A major factor in the transformation of the U.S. animal agriculture sector in terms of livestock specifications is attributed to environmentally friendly practices such as high-quality feed, heat stress reduction, improvements in reproductive ability and growth period reduction, and efforts in animal genetic enhancement.

Biochemical composition and condition of wild blackfin snook Centropomus medius through the reproductive cycle

The blackfin snook, Centropomus medius, is a valuable fish in American and Mexican markets, mainly from catches. Nonetheless, information and studies about the biology of this species still need to be made available; thus, its aquaculture should be developed. This study aimed to describe the seasonal changes of proximate composition during a reproductive cycle of C. medius, analyzing differences between tissues and their changes related to the reproductive process. The snook specimens were collected in Magdalena Bay, Baja California Sur, Mexico, and measured every month from September 2001 to November 2002. Liver, gonads, muscle tissue, and intraperitoneal fat (IPF) were sampled and weighed. The gonadosomatic index (GSI), hepatosomatic index (HSI), IPF ratio, and condition factor index (K) were calculated. The biochemical composition was analyzed in the gonad, liver, and muscle. The reproductive period (RP) of wild C. medius in Baja California Sur, Mexico, was from June to December. The spawning period was recorded at summer temperature (25-30°C) and photoperiod (>13 h daylight) starting in September. High GSI values (gonad development), low HSI values (lipid reserve mobilization), low IPF, and low K ratio were related to elevated temperatures. Moreover, variations were observed in protein, total lipid, triglycerides, and glycogen content in muscle, liver, and gonad according to the reproductive phase. A positive correlation was demonstrated between protein contents in muscle, gonad, and K, with lower concentrations during RP, while liver protein composition showed an opposite pattern. Lipids were mainly present in the liver, and the concentration decreased during RP while muscle increased. The results obtained in this study show differences in the proximate analyses in the liver, muscle, and gonads throughout the year concerning different phases of the reproductive cycle, indicating a great dependence of this process on the mobilization of reserves during C. medius reproduction. Therefore, understanding the feeding requirements to pursue the management of this species in captivity for aquaculture development is greatly important.

Fish community, seasonal movement and habitat use in a subtropical coastal lagoon

Coastal lagoons are environmentally and naturally dynamic areas crucial for fish reproduction and nursery. Thus, this research aims to evaluate the importance of the species performing their biological processes and development in this ecosystem. For this purpose, a subtropical coastal lagoon in the Gulf of California was taken as a case study, where four sampling seasonal campaigns were performed within the lagoon (internal zones) and the marine environment (external) nearby zones from 2016 to 2017. Diversity, evenness, and dominance indices were determined, and the number of individuals, size, length at first maturity, and reproductive period of each species were analyzed to obtain fish use of the lagoon. This coastal lagoon shows a high abundance of juvenile organisms in the cold season, whereas mature adults were mostly present during the warm season. Environmental variables influencing fish species development and distribution, such as sea surface temperature, salinity, and chlorophyll-a, were detected. To conclude, the subtropical coastal lagoon in the Gulf of California is an important nursery area where reproduction occurs mostly near adjacent areas.

Comparative biology and life tables of sorghum aphid Melanaphis sorghi (Theobald) (Hemiptera: Aphididae) from Mexico, at different temperatures

The sorghum aphid Melanaphis sorghi (Theobald, 1904) is the most critical pest in sorghum crops grown in the USA and Mexico. The cultivated area of sorghum was reduced by more than 30% between 2016 and 2019 in northern Mexico, Guanajuato, Morelos, and other regions. This study provides essential information to support an Integrated Pest Management of this insect. M. sorghi field colonies from Guanajuato, Mexico, were identified by morphometric criteria and reared on Sorghum bicolor var. UPM-219 leaf discs using a bioclimatic chamber under different temperatures: 5, 10, 15, 20, 25, 30, 35 and 40 °C. The highest mortality occurred in extreme temperatures: 40 °C (100%). The lowest temperature assessed (5 °C) shows no reproduction, but the pre-reproductive period spread to 62.5 days, allowing an average of 88.2 days of the insects' survival. At 20 °C, M. sorghi produced a supernumerary N5 stage that prolonged the development by 7.1 days, while at the highest temperature (40 °C), N1s died after 0.9 days. The most prolonged reproductive period was 33.2 days (0.6 nymphs/day) at 10 °C, in contrast to 4.1 days (0.4 nymphs/day) at 35 °C. The most extended post-reproductive period (22.4 days) was observed at 10 °C and the shortest (4.2 days) at 35 °C. The highest fertility average (79.06 nymphs) was reached at 25 °C. The heat units required for each generation were 158.9, while theoretical thermal thresholds were 2.0 and 40 °C. Population parameters show that 25 °C is the optimal temperature for this aphid, estimating Ro (79.06), Rm (0.44), T (10.01), DT (1.59), and λ (1.55).

The Physiological Basis of Alfalfa Plant Height Establishment.

Plant height plays an important role in crop yield, product quality, and cultivation management. However, the physiological mechanisms that regulate the establishment of plant height in alfalfa plants remain unclear. Herein, we measured plant height traits, leaf characteristics, photosynthetic physiology, cell wall composition, and endogenous hormone contents of tall- and short-stalked alfalfa materials at different reproductive periods. We analyzed the physiology responsible for differences in plant height. The results demonstrated that the number of internodes in tall- and short-stalked alfalfa materials tended to converge with the advancement of the fertility period. Meanwhile, the average internode length (IL) of tall-stalked materials was significantly higher than that of short-stalked materials at different fertility periods, with internode length identified as the main trait determining the differences in alfalfa plant height. Leaf characteristics, which are closely related to photosynthetic capacity, are crucial energy sources supporting the expression of plant height traits, and we found that an increase in the number of leaves contributed to a proportional increase in plant height. Additionally, a significant positive correlation was observed between plant height and leaf dry weight per plant during the branching and early flowering stages of alfalfa. The leaves of alfalfa affect plant height through photosynthesis, with the budding stage identified as the key period for efficient light energy utilization. Plant height at the budding stage showed a significant positive correlation with soluble sugar (SS) content and a significant negative correlation with intercellular CO2 concentration. Moreover, we found that alfalfa plant height was significantly correlated with the contents of indole-3-acetic acid in stem tips (SIAA), gibberellin A3 in leaves (LGA3), zeatin in stem tips (SZT), and abscisic acid in leaves (LABA). Further investigation revealed that SS, SIAA, and LGA3 contents were important physiological indicators affecting alfalfa plant height. This study provides a theoretical basis for understanding the formation of alfalfa plant height traits and for genetic improvement studies.

Bionomical observations of Small Carpenter Bee, Ceratina smaragdula Fibricius (Hymenoptera: Apidae)

The small carpenter bee, Ceratina smaragdula Fibricius is a non-Apis pollinator of many economically important crops. The nesting biology, nesting preferences, architects, foraging, hibernation, and mating behaviour of this solitary bee were examined in this study. Fifteen nests of C. smaragdula were collected and examined for the targeted attributes. C. smaragdula highly preferred (>80%) the area of field sides in Ravenna grass (Saccharum ravennae) for making their nests, at a preferred height of 82.74 cm from the soil surface. The nesting of C. smaragdula along roadsides and houses was 30-60% and <30%, respectively. C. smaragdula hibernated during early October to February, broke hibernation in the first week of March and initiated mating immediately. The main reproductive period was from March to August and the first generation emerged from late April to early May. The peak insect population was recorded from June to August. The mean nest length, nest diameter, and nest entrance diameter were 11.15 cm, 0.79 cm and 0.53 mm, respectively. This bee preferred a single gallery, having 3-5 cells per gallery. The gallery contents are eggs, larvae, pupae and adults. The generation development period was from 4-5 weeks and 3-4 generations per year were existed. C. smaragdula started foraging early in the morning (7.27 am) and ceased in the afternoon at (4.51 pm). The average time of foraging per flower was 21.67 seconds, and the bees returned to the nest after 7.48 min of their first forage. These findings could be helpful in designing artificial nesting required for the preservation of C. smaragdula.

Dry direct-seeded rice-wheat rotation system: Lower water and carbon footprint and higher carbon production efficiency and net ecosystem economic benefits

ContextSecuring food and energy supplies presents a significant challenge to human survival and progress. The rice-wheat rotation is one of the main food crop systems in China. However, no comprehensive assessment of the water footprint (WF), carbon footprint (CF), carbon production efficiency (CPE), and net ecosystem economic benefits (NEEB) of different rice-wheat rotation systems has been reported. ObjectiveThis study was conducted to assess the productivity, WF, CF, CPE, and NEEB of dry direct-seeded, wet direct-seeded, and transplanted rice-wheat (TR-W) rotation systems. The objective was to provide theoretical guidance for the development of clean and sustainable rice-wheat rotation production technology systems. MethodsWe used a split-plot design, with the main plots being the dry direct-seeded, wet direct-seeded, and transplanted rice planting methods, and the subplots consisting of two rice genotypes. Dry direct-seeded rice was mainly rainfed, ensuring that the soil remained relatively dry so that the soil is kept aerobic during the whole reproductive period of rice. Wet direct-seeded rice continues to keep the soil moist after sowing; the plots were maintained under a water layer of 3–10 cm following the emergence of 4.5 leaves, a condition that persisted until two weeks prior to the rice harvest. Transplanted rice was maintained under a water layer of 3–10 cm following transplanting until 2 weeks prior to the rice harvest. Subsequent to the rice harvest, the above-ground rice stubble was removed, and the ground was tilled with a rotary tiller in preparation for the subsequent wheat planting. ResultsResults demonstrated that the annual yield from the dry direct-seeded rice-wheat (DR-W) rotation system was comparable to the wet direct-seeded rice-wheat (WR-W) rotation system, while significantly lower than that of the TR-W rotation system. However, the WF of DR-W rotation system was 45.96% and 33.94% lower than that of WR-W and TR-W rotation systems, respectively, and the CF was 35.57% and 25.87% lower than that of WR-W and TR-W rotation systems, respectively. Therefore, its water and carbon production efficiencies were higher than those of WR-W and TR-W rotation systems. In addition, NEEB in DR-W and TR-W was comparable and significantly higher than that in WR-W. ConclusionsThe DR-W rotation was a promising rotation system according to the comparable annual yield, lower water and carbon footprints, higher CPE, and comparable or higher NEEB in comparison with other rice-wheat rotation systems. SignificanceWe suggest that the DR-W rotation should be promoted as the primary production mode for the rice-wheat rotation.

Effects of Aerated Drip Irrigation on the Soil Nitrogen Distribution, Crop Growth, and Yield of Chili Peppers.

In order to study the soil nitrogen (N) distribution pattern in the root zone of chili peppers under aerated drip irrigation (ADI) conditions and analyze the relationship between soil N distribution and crop growth, two irrigation methods (conventional drip irrigation and ADI) and three N levels (0, 140, and 210 kg hm-2) were set up in this experiment. Soil samples were collected by the soil auger method at the end of different reproductive periods, and the uniformity coefficient of soil N in the spatial distribution was calculated by the method of Christiansen's coefficient. The growth status and soil-related indices of pepper were determined at each sampling period, and the relationships between soil N distribution and chili pepper growth were obtained based on principal component analysis (PCA). The results showed that the spatial content of soil nitrate-N (NO3--N) fluctuated little during the whole reproductive period of chili peppers under ADI conditions, and the coefficient of uniformity of soil NO3--N content distribution increased by 5.29~37.63% compared with that of conventional drip irrigation. The aerated treatment increased the root length and surface area of chili peppers. In addition, the ADI treatments increased the plant height, stem diameter, root vigor, and leaf chlorophyll content to some extent compared with the nonaerated treatment. The results of PCA showed that the yield of chili peppers was positively correlated with the uniformity coefficient of soil NO3--N, root vigor, and root length. ADI can significantly improve the distribution uniformity of soil NO3--N and enhance the absorption and utilization of N by the root system, which in turn is conducive to the growth of the crop, the formation of yields, and the improvement of fruit quality.

Torsion in Uterus: An Obstetrical and Gynaecological Emergency.

Uterine torsion is defined as torsion of the uterus along its longitudinal axis greater than 45 degrees. It is observed in all age groups of the reproductive period, in all parity groups, and at all stages of pregnancy. Torsion from 60degrees to 720degrees has been described. It is not possible to clarify why it occurs, but numerous abnormalities have appeared with uterine torsion. It is a rare complication that can result in placental abruption and intrauterine foetal death. Pregnancy, giant fibroids, and ovarian cysts are among the most common causes. Vague clinical attributes make diagnosis challenging pre-operatively and can be missed on routine ultrasound. Being a rare life-threatening condition, it necessitates a high level of concern for diagnosis and prompt intervention to optimise results. This review will help the healthcare worker to understand the various presentation of uterine torsion and their management by appropriately and timely diagnosing it.

Individual and community-level determinants of knowledge about fertile periods among adolescent girls and young women (10–24 years) in Sub-Saharan Africa: A multilevel mixed effect analysis of a recent demographic and health survey

BackgroundIdentifying fertility periods accurately will protect teenage girls and young women from unintended pregnancies and related complications. However, in Sub-Saharan Africa, knowledge of the fertile period among adolescent girls and young women is not well studied. Thus, the purpose of this study was to assess adolescents' and young women's knowledge regarding fertility periods and its determinants in Sub-Saharan Africa. MethodsThe most recent demographic and health surveys' data were used. The study had 140,064 participants in all. The data was analyzed using STATA/SE version 14. Using a multilevel logistic regression model, factors associated with knowledge of fertile periods have been determined. P-values <0.05 showed the significance of the factors associated with the outcome variable. The data were interpreted using the adjusted odds ratio and confidence interval. The best-fit model was determined to be the one with the highest logliklihood ratio and the lowest deviance. ResultsOne in five (20%) women between the ages of 10 and 24 had accurate knowledge about the fertile period. Age (AOR = 1.44, 95% CI: 1.40, 1.49), educational level (AOR = 1.68, 95% CI: 1.60, 1.77), knowledge of family planning (AOR = 1.33, 95% CI: 1.27, 1.39), distance (AOR = 2.31, 95% CI: 2.02, 2.98), residence (AOR = 1.06, 95% CI: 1.02, 1.10), and low community poverty (AOR = 3.06, 95% CI: 3.01, 3.12) had higher odds of knowledge about fertile period. ConclusionThis research finds that adolescents and young women in sub-Saharan Africa have low knowledge of the reproductive period. It was discovered that factors at the individual and communal levels influence women's knowledge of the fertile period. While developing policies and strategies, the health ministries of Sub-Saharan African countries had to take into consideration input from women whose experiences indicated that obtaining reproductive health services was hindered by distance.

Genome-Wide Association Studies Prioritize Genes Controlling Seed Size and Reproductive Period Length in Soybean.

Hundred-seed weight (HSW) and reproductive period length (RPL) are two major agronomic traits critical for soybean production and adaptation. However, both traits are quantitatively controlled by multiple genes that have yet to be comprehensively elucidated due to the lack of major genes; thereby, the genetic basis is largely unknown. In the present study, we conducted comprehensive genome-wide association analyses (GWAS) of HSW and RPL with multiple sets of accessions that were phenotyped across different environments. The large-scale analysis led to the identification of sixty-one and seventy-four significant QTLs for HSW and RPL, respectively. An ortholog-based search analysis prioritized the most promising candidate genes for the QTLs, including nine genes (TTG2, BZR1, BRI1, ANT, KLU, EOD1/BB, GPA1, ABA2, and ABI5) for HSW QTLs and nine genes (such as AGL8, AGL9, TOC1, and COL4) and six known soybean flowering time genes (E2, E3, E4, Tof11, Tof12, and FT2b) for RPL QTLs. We also demonstrated that some QTLs were targeted during domestication to drive the artificial selection of both traits towards human-favored traits. Local adaptation likely contributes to the increased genomic diversity of the QTLs underlying RPL. The results provide additional insight into the genetic basis of HSW and RPL and prioritize a valuable resource of candidate genes that merits further investigation to reveal the complex molecular mechanism and facilitate soybean improvement.

The intake of ultra-processed foods and homocysteine levels in women with(out) overweight and obesity: The Rotterdam Periconceptional Cohort

PurposeToday’s diet consists of a substantial proportion of ultra-processed foods (UPF), especially in women with overweight and obesity in the reproductive period. High UPF intake results in an inadequate and unbalanced diet leading to derangements of several metabolic pathways detrimental to pregnancy and birth outcomes. Therefore, we aim to investigate whether UPF intake in the periconceptional period affects total homocysteine plasma levels (tHcy).Methods1532 participants were included from the prospective Rotterdam Periconceptional Cohort. UPF intake was calculated using Food Frequency Questionnaires including items classified as 4 in the Nova classification, and tHcy was measured by using liquid chromatography-tandem mass spectrometry system, with an interassay coefficient of variation of < 5.5%. Multivariable linear regression modeling was used and adjusted for covariates and significant interaction terms.ResultsWomen with overweight or obesity showed significantly higher percentage of UPF intake (respectively, 50.3 and 51.3%) and higher tHcy (respectively, 6.6 and 6.3 µmol/L, Kruskal–Wallis test; respectively, p < 0.001 and p = 0.04) compared to women with normal BMI (UPF intake: 46.8%, tHcy: 6.1 µmol/L). A 10% higher intake of UPF was associated with an increase in tHcy (adjusted: β = 1.31, 95% CI = 0.38–2.23). Analysis stratified for BMI classification showed comparable associations in normal weight participants (adjusted: β = 1.07, 95% CI = 0.06–2.07); however, no significant association in participants with overweight (adjusted: β = 0.06, 95% CI = − 0.95–1.07) and obesity (adjusted: β = 1.70, 95% CI = − 0.52–3.92) was shown.ConclusionThis study showed that a higher intake of UPF is associated with increased tHcy. Better knowledge and awareness of the nutritional quality of the diet in the periconceptional period may contribute to 1-CM and subsequently improve pregnancy course and outcome.Trial registration number and dateNTR4356, November 2010.

Differential expression of reproduction‐related genes in shrimps from East Pacific fisheries

AbstractShrimp fisheries and culture are important food sources worldwide. Central East Pacific fisheries are mainly supported by four species: Penaeus brevirostris, P. californiensis, P. stylirostris and P. vannamei. However, the same shrimp fishery practices, management strategies and closures are applied to these four species despite their differences in life history and reproductive periods. Most molecular studies have focused on the cultured species P. vannamei, while knowledge for the rest of the species is scarce. Therefore, this study sought to examine the transcriptomes of these four shrimp species from the Mexican Pacific at different maturity stages. A total of 165 unigenes were found to be reproduction‐related in the four shrimp species. The genes with the highest overall expression levels were associated with ribosomes, transcription and methyltransferase pathways. Moreover, the reproduction‐related genes with the highest expression values were polehole protein and ovarian peritrophin. The major expression similarities were primarily among pre‐vitellogenic and vitellogenic females within each species, and secondly among the species P. brevirostris and P. californiensis and the species P. vannamei and P. stylirostris. Although these four species might share a geographical location or niche, the expression of reproduction related‐genes at different gonadal maturity stages exhibited species‐specific variations.

Testosterone is closely related to Leydig cell activity, environmental factors, and androgen receptor distribution in adult male lizards of Liolaemus cuyanus (Reptilia: Liolaemidae) during the reproductive cycle.

Testosterone, the primary sex hormone in male lizards, is closely linked to Leydig cell activity (the cells where steroidogenesis occurs) throughout the reproductive cycle, but testosterone action is related to androgen receptors (ARs) distribution in the seminiferous epithelium. In temperate zones, environmental factors detected through the hypothalamic-pituitary-gonadal axis, downregulate plasma testosterone, resulting in a seasonal reproductive cycle. The aim of this work is to study plasma testosterone in adult male lizards of Liolaemus cuyanus, an oviparous species, throughout its reproductive cycle and its relationship with Leydig cell histology, TotalLeydigCell/ActiveLeydigCell (TLC/ALC) ratio, environmental factors (temperature, relative humidity and solar irradiation) and ARs distribution in seminiferous epithelium. Specimens (N = 27) were captured (October to March) in a semi-arid zone (Valle de Matagusanos, San Juan, Argentina) and grouped into three relevant reproductive periods: pre-reproductive (PrR), reproductive (R), and post-reproductive (PsR). Significant differences in plasma testosterone were found among these periods, highest during R than in PsR. A significant positive correlation between plasma testosterone and TLC/ALC ratio was also observed. Plasma testosterone has a significant positive correlation only with solar irradiation, but not with the other variables. In PrR and R, ARs distribution was cytoplasmic and nuclear, shifting to only cytoplasmic in PsR. These results highlight the close correspondence between plasma testosterone, Leydig cell histology and activity, environmental factors, and ARs distribution, resulting in a synchronization that allows males of L. cuyanus to coordinate their reproductive cycle with the most favorable environmental conditions, probably for mating and birth of offspring.

Heat stress at the bicellular stage inhibits sperm cell development and transport into pollen tubes.

For successful double fertilization in flowering plants (angiosperms), pollen tubes deliver two non-motile sperm cells towards female gametes (egg and central cell, respectively). Heatwaves, especially during the reproduction period, threaten male gametophyte (pollen) development, resulting in severe yield losses. Using maize (Zea mays) as a crop and grass model system, we found strong seed set reduction when moderate heat stress was applied for two days during the uni- and bicellular stages of pollen development. We show that heat stress accelerates pollen development and impairs pollen germination capabilities when applied at the unicellular stage. Heat stress at the bicellular stage impairs sperm cell development and transport into pollen tubes. To understand the course of the latter defects, we used marker lines and analyzed the transcriptomes of isolated sperm cells. Heat stress affected the expression of genes associated with transcription, RNA processing and translation, DNA replication, and the cell cycle. This included the genes encoding centromeric histone 3 (CENH3) and α-tubulin. Most genes that were mis-regulated encode proteins involved in the transition from metaphase to anaphase during pollen mitosis II (PM II). Heat stress also activated spindle assembly check point and meta- to anaphase transition genes in sperm cells. In summary, mis-regulation of the identified genes during heat stress at the bicellular stage results in sperm cell development and transport defects ultimately leading to sterility.

Gaps between Rice Actual and Potential Yields Based on the VPM and GAEZ Models in Heilongjiang Province, China

Heilongjiang Province is a significant region for grain production and serves as a crucial commodity grain production base in China. In recent years, due to the threat of declining cropland quality and quantity, coupled with the increasingly prominent demand for grain, there is an urgent need to enhance rice yields in Heilongjiang Province. It is imperative to accurately identify the gaps between actual and potential grain yields and effectively implement yield-enhancing measures in regions with significant yield gaps. This study aimed to determine the rice reproductive periods of Heilongjiang Province for 2000, 2010, and 2020, estimate the rice actual yields using the Vegetation Photosynthesis Model (VPM), simulate the rice potential yields based on the Global Agro-Ecological Zones (GAEZ) Model, and then identify the rice yield gaps at the pixel level by calculating the rice absolute yield gap (AYG) and relative yield gap (RYG). Additionally, yield-enhancing measures were proposed for regions with significant yield gaps. The results were as follows. (1) The rice reproductive periods of Heilongjiang Province for 2000, 2010, and 2020 were determined as days 153~249, days 145~249, and days 137~249. (2) The mean rice actual yield and potential yields decreased by 1222 and 5941 kg ha−1 during the 2000–2020 period, respectively, and the total actual and potential production increased by 3.75 and 1.70 million tons in Heilongjiang Province, respectively. (3) The rice AYG and RYG in the Sanjiang Plain region, such as Jixi City, Hegang City, and Jiamusi City were relatively large compared to other regions for the three years, and the rice yield gaps continued to decrease during the 2000–2020 period. (4) With regard to the Sanjiang Plain region with a large rice yield gap, this study proposes measures to narrow the rice yield gap by establishing ecological protection forests on cropland, transforming low- and middle-yielding fields, increasing agricultural science and technology inputs, selecting better rice cultivars, etc., which are important for ensuring food security.

Characterization of anthropogenic noise and oyster toadfish (Opsanus tau) calling behavior in urban and small-town coastal soundscapesa).

The oyster toadfish (Opsanus tau) is an ideal model to examine the effects of anthropogenic noise on behavior because they rely on acoustic signals for mate attraction and social interactions. We predict that oyster toadfish have acclimated to living in noise-rich environments because they are common in waterways of urban areas, like New York City (NYC). We used passive acoustic monitoring at two locations to see if calling behavior patterns are altered in areas of typically high boat traffic versus low boat traffic (Pier 40, NYC, NY, and Eel Pond, Woods Hole, MA, respectively). We hypothesized that toadfish in NYC would adjust their circadian calling behavior in response to daily anthropogenic noise patterns. We quantified toadfish calls and ship noise over three 24-h periods in the summer reproductive period at both locations. We observed an inverse relationship between the duration of noise and the number of toadfish calls at Pier 40 in comparison to Eel Pond. Additionally, toadfish at Pier 40 showed significant differences in peak calling behavior compared to Eel Pond. Therefore, oyster toadfish may have acclimated to living in an urban environment by potentially altering their communication behavior in the presence of boat noise.

Control Effects of Short-Term Heatwaves on a Holocyclic Aphid.

The soybean aphid, A. glycines, is an important soybean pest. Harbin, in the Heilongjiang Province, is an area with increasing temperatures in China that faces frequent short-term heatwaves. In this study, the development, reproduction, and morph differentiation of A. glycines have been studied when they were exposed to diurnal at 35 °C for seven days, beginning at different developmental stages. The nymph stage duration of A. glycines was longer, the adult lifespans and total lifespans were shorter, and their bodies were smaller when exposed to a diurnal of 35 °C beginning at the 1st to 4th stadium. The adult reproduction period was shorter, and the adult fecundity and intrinsic rate of increase were smaller than those of aphids reared at a diurnal of 25 °C. A higher and lower proportion of gynoparae and males were deposited as offspring on day 13 by adults when exposed to diurnal at 35 °C, beginning at the 1st to 4th stadium, respectively, than those of aphids reared at a constant of 20 °C. These results are important for predicting the dynamics of A. glycines in Harbin soybeans. This provides evidence that short-term heatwaves are probably useful for controlling A. glycines, by inhibiting development and male morphogenesis.

Induksi Kalus dari Hipokotil Belimbing Merah (Baccaurea angulata) dengan Penambahan 2,4-D (Dichlorophenoxy Acetic Acid) dan BAP (6-Benzyl Amino Purin)

Red starfruit is one of the endemic plants of Kalimantan which produces secondary metabolites which has been empirically used as antioxidant, antibacterial, and anticancer. This plant has a long reproductive period and seedless fruit is often found during the fruiting season, which is a problem for the sustainability of the red starfruit in nature. Conservation of red star fruit for propagation and production of secondary metabolites can be done in vitro through callus culture. This research aims to determine the effect of adding the growth regulators dichlorophenoxy acetic acid (2,4-D) and 6-benzyl amino purine (BAP) on callus induction time, percentage of callus forming explants, callus color and texture, and callus growth. This research used a Completely Randomized Design (CRD) with a factorial pattern consisting of two treatment factors, namely 2,4-D (0; 0.25; 0.5; 0.75; 1 ppm) and BAP (0; 0.25; 0.5; 0.75; 1 ppm). The percentage of explants forming callus (%), the time the callus appeared (days after planting), the color and texture of the callus, the wet weight and dry weight of the callus (g) were research observation parameters.The results showed that the single factor 2,4-D, single factor BAP, and the interaction of 2,4-D and BAP had a significant effect to callus appearance time. Single administration of 2,4-D and BAP had a significant effect on callus dry weight. The color variations of the callus produced are white, green and brown with a compact texture. The fastest callus emergence time was at 11.00 days after planting (DAP), namely in the combination treatment of 1 ppm 2,4-D and 0.75 ppm BAP, single treatment 0.75 ppm and 1 ppm 2,4- D. The highest average dry weight of 0.024 g was obtained in the single treatment of 0.75 ppm BAP.