Water is the key factor limiting dryland wheat grain yield.  Mulching affects crop yield and yield components by affecting soil moisture.  Further research is needed to determine the relationships between yield components and soil moisture with yield, and to identify the most important factor affecting grain yield under various mulching measures.  A long-term 9-year field experiment in the Loess Plateau of Northwest China was carried out with three treatments: no mulch (CK), plastic mulch (M_P) and straw mulch (M_S).  Yield factors and soil moisture were measured, and the relationships between them were explored by correlation analysis, structural equation modeling and significance analysis.  The results showed that compared with CK, the average grain yields of M_P and M_S increased by 13.0 and 10.6%, respectively.  The average annual grain yield of the M_P treatment was 134 kg ha^–1 higher than the M_S treatment.  There were no significant differences in yield components among the three treatments (P<0.05).  Soil water storage of the M_S treatment was greater than the M_P treatment, although the differences were not statistically significant.  Soil water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of M_S were significantly higher than in CK, which increased by 38.5 and 13.6%, respectively.  The relationship between M_P and CK was not statistically significant for SWSSF, but the SWSS in M_P was significantly higher than in CK.  In terms of soil water storage after harvest (SWSH) and water consumption in the growth period (ET), there were no significant differences among the three treatments.  Based on the three analysis methods, we found that spike number and ET were positively correlated with grain yield.  However, the relative importance of spike number to yield was the greatest in the M_P and M_S treatments, while that of ET was the greatest in CK.  Sufficient SWSSF could indirectly increase spike number and ET in the three treatments.  Based on these results, mulch can improve yield and soil water storage.  The most important factor affecting the grain yield of dryland wheat was spike number under mulching, and ET with CK.  These findings may help us to understand the main factors influencing dryland wheat grain yield under mulching conditions compared to CK.

Grain weight is one of the key components of wheat (Triticum aestivum L.) yield.  Genetic manipulation of grain weight is an efficient approach for improving yield potential in breeding programs.  A recombinant inbred line (RIL) population derived from a cross between W7268 and Chuanyu 12 (CY12) was employed to detect quantitative trait loci (QTLs) for thousand-grain weight (TGW), grain length (GL), grain width (GW), and the ratio of grain length to width (GLW) in six environments.  Seven major QTLs, QGl.cib-2D, QGw.cib-2D, QGw.cib-3B, QGw.cib-4B.1, QGlw.cib-2D.1, QTgw.cib-2D.1 and QTgw.cib-3B.1, were consistently identified in at least four environments and the best linear unbiased estimation (BLUE) datasets, and they explained 2.61 to 34.85% of the phenotypic variance.  Significant interactions were detected between the two major TGW QTLs and three major GW loci.  In addition, QTgw.cib-3B.1 and QGw.cib-3B were co-located, and the improved TGW at this locus was contributed by GW.  Unlike other loci, QTgw.cib-3B.1/QGw.cib-3B had no effect on grain number per spike (GNS).  They were further validated in advanced lines using Kompetitive Allele Specific PCR (KASP) markers, and a comparison analysis indicated that QTgw.cib-3B.1/QGw.cib-3B is likely a novel locus.  Six haplotypes were identified in the region of this QTL and their distribution frequencies varied between the landraces and cultivars.  According to gene annotation, spatial expression patterns, ortholog analysis and sequence variation, the candidate gene of QTgw.cib-3B.1/QGw.cib-3B was predicted.  Collectively, the major QTLs and KASP markers reported here provide valuable information for elucidating the genetic architecture of grain weight and for molecular marker-assisted breeding in grain yield improvement.

Wheat grain morphology is an important breeding target considering its impact on yield and end-use properties.  However, the genetic basis of grain roundness, a major determinant of grain morphology, remains largely unexplored.  In this study, an F₂ and a recombinant inbred line (RIL) populations from Zhongkemai 138 (ZKM138)×Chinese Spring (CS) cross were employed to analyze the genetic basis of grain shape variation.  Kompetitive Allele Specific PCR (KASP) markers were developed according to single nucleotide polymorphism (SNP) from bulked segregant exome sequencing (BSE-Seq) of F₂ and Wheat 55K SNP array data online, and then were used to construct two genetic maps of F₂ and RIL populations, spanning 148.89 cM (30 KASP markers) and 129.82 cM (25 KASP markers), respectively.  By the traditional QTL mapping method based on these two maps, a stable quantitative trait locus (QTL) for grain roundness (GR), QGr.cib-5A, could be repeatedly highlighted in the interval of 444.8-455.5 Mb on chromosome 5A.  Further conditional QTL mapping analysis revealed that grain width was the major contributor to GR at this locus.  Besides, the utilization of two tightly linked markers 5A4-15 and 55k-31 showed a 96.27% transmissibility of ZKM138-derived alleles in 134 ZKM138 derivatives alongside a 7.38% increase in GR, and a 65.19% distribution of worldwide varieties.  Finally, TraesCS5A02G236400, possibly encoding a hydroxyproline-rich glycoprotein family protein, was deduced to be the candidate gene.  Collectively, these results provided the possibility of facilitating wheat grain shape improvement and enhancing wheat market value.

In floodplain wetlands, alterations in hydrological patterns resulting from climate change and human activities could potentially diminish the carbon sequestration capacity of the soils, thereby having a negative impact on global climate change. However, the magnitude of the influence of hydrological regime change on soil carbon remains inadequately monitored. To address this research gap, we collected 306 upper layer (0-20 cm) soil samples from the Dongting Lake floodplain between 2013 and 2022. The Random Forest (RF) algorithm was used to analyze the spatial distribution of soil organic carbon (SOC) in the upper soil layer of Dongting Lake floodplain and the impact of climate and hydrological changes in the past decade on surface SOC in the East Dongting Lake area was studied. In 2022, the SOC concentration of the Dongting Lake floodplain upper layer soil ranged from 3.34 to 17.67 g kg^-1, averaging 10.43 g kg^-1, with a corresponding SOC density of 2.65±0.49 kg m^-2 and total SOC stock of 6.82 Tg C (2.87–13.48 Tg C). From 2013 to 2022, the SOC concentration of the upper soil layer of the East Dongting Lake area decreased from 18.37 g kg^-1 to 10.82 g kg^-1. This reduction could be attributed to climate and hydrological changes which reduce SOC input by reducing vegetation growth and accelerating SOC decomposition. Above 21.4 m elevation, the amount of SOC loss increased with elevation, the loss being related to the decline in Miscanthus community biomass and greater susceptibility of higher altitude areas to climate and hydrological changes. Our results highlight the need for strengthening wetland SOC management to increase SOC in the soils to help combat climate change.

Adjustment of the sowing date is a widely used measure in rice production to adapt to high-temperature conditions.  However, the impact of delayed sowing date (DS) on rice quality may vary by variety and ecological conditions.  In this study, we conducted experiments using different sowing dates, that is, conventional sowing date 1 (CS1), CS2 (10 d later than CS1), DS1 (30 d later than CS1), and DS2 (30 d later than CS2), and three rice varieties, i.e., “Yixiangyou 2115,” “Fyou 498,” and “Chuanyou 6203.”  This experiment was conducted at four sites in the Sichuan basin in 2018 and 2019 to evaluate the influence of DS on the pasting properties of rice, which are a proxy for eating and cooking quality (ECQ).  In DS1 and DS2, rice had a significantly greater amylose content (AC) but a lower protein content (PC), peak viscosity (PKV), cool paste viscosity (CPV), and hot paste viscosity (HPV) than in CS1 and CS2.  Moreover, with the exception of CS2 and DS1 in 2018, DS1 and DS2 led to a 2.15–11.19% reduction in breakdown viscosity (BDV) and a 23.46–108.47% increase in setback viscosity (SBV).  However, the influence of DS on rice pasting properties varied by study site and rice variety.  In 2019, DS1 and DS2 led to a BDV reduction of 2.35–9.33, 2.61–8.61, 10.03–17.78, and 2.06–8.93%, and a SBV increase of 2.32–60.93, 63.74–144.24, 55.46–91.63, and -8.28–65.37% at the Dayi, Anzhou, Nanbu, and Shehong, respectively. DS resulted in a greater decrease in PKV, HPV, CPV, and BDV and a greater increase in the AC and SBV for Yixiangyou 2115 than for Chuanyou 6203 and Fyou 498.  Correlation analysis indicated that PKV and HPV were significantly and positively related to the mean, maximum, and minimum temperatures after heading.  These temperatures have to be greater than 25.9, 31.2, and 22.3℃ to increase the relative BDV and decrease the relative SBV of rice, thereby enhancing ECQ.  In conclusion, DS might contribute to a significant deterioration in ECQ in machine-transplanted rice in the Sichuan basin.  A mean temperature above 25.9℃ after heading is required to improve the ECQ of rice.

The development of skeletal muscle are complicated processes involving genes responsible for proper muscle morphology, contractility, cell proliferation, differentiation, interactions, migration, and death. The three-dimensional chromatin architecture of skeletal muscle development has not been studied intensively although dynamic transcriptional regulation during differentiation of muscle cells is one of the most deeply studied processes. The RNA-seq was used to analyze the transcriptome pattern during chicken muscle development across 12 stages. Hi-C was used to build a chromatin architectures during four representative stages. ChIP-seq was conducted to identify enhancers in these four stages, which are occupied by histone H3K27ac and H3K4me3 peaks. Results show that large-scale genome architecture changes are mostly unidirectional, and coupled by complex on/off dynamic patterns of gene expression. Specifically, we observed 258.30 Mb of the genome undergoing A/B compartment switching. Notable alterations (316.57 Mb) of interaction frequencies within TADs were observed. Substantial aging-associated genes exhibited ascending connectivity with the compartment transition from repressive to active status during muscle development. Some muscle-related gene promoters that interacted with active enhancers during development, and some myopathy/aging-associated genes that were activated in aging muscle were founded. These results provide key insights into skeletal muscle development in vivo, and offer a valuable resource that allows in-depth functional characterization of candidate genes.

Recent studies have shown that lipid metabolism is a key factor affecting anther development and male fertility. However, how plants regulating the metabolic balance of multiple lipids to ensure proper anther development and male fertility remains unclear. Analyzing lipid molecules related to anther fertility and genes responsible for their biosynthesis is crucial for understanding the physiological significance of lipid metabolism in crop fertility. In this study, we compared the transcriptome and the composition and content of lipids in anthers of two Upland cotton (Gossypium hirsutum) materials, Shida 98 (WT) and its nearly-isogenic male sterile line Shida 98A (MS). Transcriptomics analysis identified many differentially expressed genes between the two materials, with the genes of the alpha-linolenic acid metabolism pathway being the most significantly associated with the male sterility phenotype. Investigations on lipids revealed that the MS anthers over-accumulated free fatty acids (FFAs), phosphatidic acid (PA), mono- and di-galactosyldiacylglycerol (MGDG and DGDG), and had a decreased content of triacylglycerol (TAG), which was closely related to the abnormal metabolism of alpha-linolenic acid (C18:3); therefore, the major lipids containing C18:3-acyl chains, such as PA, MGDG, DGDG and TAG, are proposed to play a major role in cotton anther development. We also showed that an excessive level of MGDG and DGDG caused JA overaccumulation in MS anthers, which in turn inhibited the expression of GhFAD3 and consequently reduced the C18:3 content, presumably via a feedback regulation mechanism, ultimately affecting plant fertility. Together, our results revealed the importance of a balanced lipid metabolism in regulating the development of cotton anther and pollen and consequently male fertility.