Peanut pod shape is a heritable trait which affects the market acceptance of in-shell peanut products.  In order to determine the genetic control of pod shape, six component traits of pod shape (pod length, pod width, pod length/width ratio, pod roundness, beak degree and constriction degree) were measured using an image-based phenotyping method.  A recombinant inbred line (RIL) population consisting of 181 lines was phenotyped across three environments.  Continuous distributions and transgressive segregations were demonstrated in all measured traits and environments.   Significant correlations were found among most component traits with broad-sense heritability ranging from 0.87 to 0.95.  Quantitative trait locus (QTL) analysis yielded 26 additive QTLs explaining 3.79 to 52.37% phenotypic variations.  A novel, stable and major QTL region conditioning multiple shape features was detected on chromosome 2, which spans a 10.81-Mb genomic region with 543 putative genes.  Bioinformatics analysis revealed several candidate genes in this region.  In addition, 73 pairs of epistatic interactions involving 92 loci were identified for six component traits explaining 0.94–6.45% phenotypic variations.  These results provide new genetic loci to facilitate genomics-assisted breeding of peanut pod shape.

In higher plants, the shoot apical meristem produces lateral organs in a regular spacing (phyllotaxy) and timing (plastochron).  The molecular analysis of mutants associated with phyllotaxy and plastochron would increase our understanding of the mechanism of shoot architecture formation.  In this study, we identified mutant mnd8^ynp5 that shows an increased rate of leaf emergence and a larger number of nodes in combination with a dwarfed growth habit from an EMS-treated population of the elite barley cultivar Yangnongpi 5.  Using a map-based cloning strategy, the mnd8 gene was narrowed down to a 6.7-kb genomic interval on the long arm of chromosome 5H.  Sequence analysis revealed that a C to T single-nucleotide mutation occurred at the first exon (position 953) of HORVU5Hr1G118820, leading to an alanine (Ala) to valine (Val) substitution at the 318th amino acid site.  Next, HORVU5Hr1G118820 was defined as the candidate gene of MND8 encoding 514 amino acids and containing two multidrug and toxic compound extrusion (MATE) domains.  It is highly homologous to maize Bige1 and has a conserved function in the regulation of plant development by controlling the leaf initiation rate.  Examination of modern barely varieties showed that Hap-1 was the dominant haplotype and was selected in barley breeding around the world.  Collectively, our results indicated that mnd8^ynp5 is a novel allele of the HORVU5Hr1G118820 gene that is possibly responsible for the shortened plastochron and many noded dwarf phenotype in barley.

Nitrogen (N) and seeding rates are important factors affecting grain yield and N use efficiency (NUE) in direct-seeded rice.  However, these factors have not been adequately investigated on direct-seeded and double-season rice (DDR) in Central China.  The objective of this study was to evaluate the effects of various N and seeding rates on the grain yield and NUE of an ultrashort-duration variety grown under DDR.  Field experiments were conducted in 2018 in Wuxue County and 2019 in Qichun County, Hubei Province, China with four N rates and three seeding rates.  The results showed that the grain yield of the ultrashort-duration variety ranged from 6.32 to 8.23 t ha^–1 with a total growth duration of 85 to 97 days across all treatments with N application.  Grain yield was increased significantly by N application in most cases, but seeding rate had an inconsistent effect on grain yield.  Furthermore, the response of grain yield to the N rates was much higher than the response to seeding rates.  The moderate N rates of 100–150 and 70–120 kg N ha^–1 in the early and late seasons, respectively, could fully express the yield potential of the ultrashort-duration variety grown under DDR.  Remarkably higher N responses and agronomic NUE levels were achieved in the early-season rice compared with the late-season rice due to the difference in indigenous soil N supply capacity (INS) between the two seasons.  Seasonal differences in INS and N response should be considered when crop management practices are optimized for achieving high grain yield and NUE in ultrashort-duration variety grown under DDR.

Drought and salt stresses, the major environmental abiotic stresses in agriculture worldwide, affect plant growth, crop productivity, and quality.  Therefore, developing crops with higher drought and salt tolerance is highly desirable.  This study reported the isolation, biological function, and molecular characterization of a novel maspardin gene, OsMas1, from rice.  The OsMas1 protein was localized to the cytoplasm.  The expression levels of OsMas1 were up-regulated under mannitol, PEG6000, NaCl, and abscisic acid (ABA) treatments in rice.  The OsMas1 gene was introduced into the rice cultivar Zhonghua 11 (wild type, WT).  OsMas1-overexpression (OsMas1-OE) plants exhibited significantly enhanced salt and drought tolerance; in contrast, OsMas1-interference (OsMas1-RNAi) plants exhibited decreased tolerance to salt and drought stresses, compared with WT.  OsMas1-OE plants exhibited enhanced hypersensitivity, while OsMas1-RNAi plants showed less sensitivity to exogenous ABA treatment at both germination and post-germination stages.  ABA, proline and K⁺ contents and superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and photosynthesis activities were significantly increased.  In contrast, malonaldehyde (MDA), hydrogen peroxide (H₂O₂), superoxide anion radical (O₂^-·), and Na⁺ contents were significantly decreased in OsMas1-OE plants compared with OsMas1-RNAi and WT plants.  Overexpression of OsMas1 up-regulated the genes involved in ABA signaling, proline biosynthesis, reactive oxygen species (ROS)-scavenging system, photosynthesis, and ion transport under salt and drought stresses.  Our results indicate that the OsMas1 gene improves salt and drought tolerance in rice, which may serve as a candidate gene for enhancing crop resistance to abiotic stresses.

The rice cultivars carrying dep1 (dense and erect panicle 1) have the potential to achieve both high grain yield and high nitrogen use efficiency (NUE).  However, few studies have focused on the agronomic and physiological performance of those cultivars associated with high yield and high NUE under field conditions.  Therefore, we evaluated the yield performance and NUE of two near-isogenic lines (NILs) carrying DEP1 (NIL-DEP1) and dep1-1 (NIL-dep1) genes under the Nanjing 6 background at 0 and 120 kg N ha^–1.  Grain yield and NUE for grain production (NUEg) were 25.5 and 21.9% higher in NIL-dep1 compared to NIL-DEP1 averaged across N treatments and planting years, respectively.  The yield advantage of NIL-dep1 over NIL-DEP1 was mainly due to larger sink size (i.e., higher total spikelet number), grain-filling percentage, total dry matter production, and harvest index.  N utilization rather than N uptake contributed to the high yield of NIL-dep1.  Significantly higher NUEg in NIL-dep1 was associated with higher N and dry matter translocation efficiency, lower leaf and stem N concentration at maturity, and higher glutamine synthetase (GS) activity in leaves.  In conclusion, dep1 improved grain yield and NUE by increasing N and dry matter transport due to higher leaf GS activity under field conditions during the grain-filling period.

Lodging is the most common constraint on grain yield of direct-seeded rice.  There is limited information about lodging resistance and its related plant traits in direct-seeded and double-season rice (DDR) in Central China.  This study aims  to identify the plant traits that achieve high lodging resistance in ultrashort-duration varieties (about 95 days) of DDR.  Field experiments were conducted in 2017 and 2018 in Wuxue County, Hubei Province, China, with four ultrashort-duration varieties grown under two nitrogen (N) rates.  Lodging-related traits were measured on the 15th day after heading, and yield and yield attributes were measured at maturity.  The grain yield of the four varieties ranged from 4.59 to 7.61 t ha^–1 across the two N rates, with a total growth duration of 85 to 97 days.  Varietal differences in lodging index were mainly explained by the bending moment, which was closely related to plant height.  Breaking resistance did not affect the lodging index significantly.  Shortening plant height from 95.4 to 80.5 cm decreased the lodging index by 22.4% but did not reduce grain yield.  Our results suggested that reducing plant height was effective in improving the lodging resistance of ultrashort-duration varieties of DDR.  Lodging resistance should be enhanced by improving breaking resistance rather than reducing plant height to increase DDR grain yield further.

In biological research, chicken embryos are a classic experimental model for the exploration of the embryonic development and cell differentiation.  Transferring exogenous substances into chicken embryos for producing medical antibodies has been widely used in the production practice.  However, there are few studies about the effect of the different injection site and dosage on chicken embryos.  The aim of this study was to explore the effects of different injection sites and dosages on chicken embryo hatching rate and development, so as to provide a basis for further studies using the chicken embryo model.  Freshly laid eggs (Rugao yellow chicken) were injected with different doses of saline at the tip, equatorial plane and the blunt end of the egg shell, respectively.  Egg hatching rate was recorded and compared among injection sites and different doses.  A trypan blue stain was also injected at the aforementioned sites and the growth of chicken embryos was observed.  The SPSS (statistical package for the social science) software was used to analyze the relationship between the chicken eggs hatching rate and the different injection sites or the different dosages.  The experimental results showed that there were significant differences on egg hatching rates among the different injection sites and doses (P<0.05).  The hatchability of the blunt end injection group was significantly higher than that of the other two sites.  The egg hatching rate decreased with increased saline doses.  The egg hatching rate of the 100 µL saline injection group was higher than the 200 and 300 µL dosage groups.  Ultimately, we suggest that the optimal chicken embryo injection process is during early development, at the blunt end site with a dose less than 100 µL to minimize damage to the egg.

In 1996, a mega project that aimed to develop rice varieties with super-high yield potential (super rice) was launched by the Ministry of Agriculture (MOA) in China using a combination of the ideotype approach and intersubspecific heterosis.  Significant progress has been made in the last two decades, with a large number of super rice varieties being approved by the MOA and the national average grain yield being increased from 6.21 t ha⁻¹ in 1996 to 6.89 t ha⁻¹ in 2015.  The increase in yield potential of super rice was mainly due to the larger sink size which resulted from larger panicles.  Moreover, higher photosynthetic capacity and improved root physiological traits before heading contributed to the increase in sink size.  However, the poor grain filling of the later-flowering inferior spikelets and the quickly decreased root activity of super rice during grain filling period restrict the achievement of high yield potential of super rice.  Furthermore, it is widely accepted that the high yield potential of super rice requires a large amount of N fertilizer input, which has resulted in an increase in N consumption and a decrease in nitrogen use efficiency (NUE), although it remains unclear whether super rice per se is responsible for the latter.  In the present paper, we review the history and success of China’s Super Rice Breeding Program, summarize the advances in agronomic and physiological mechanisms underlying the high yield potential of super rice, and examine NUE differences between super rice and ordinary rice varieties.  We also provide a brief introduction to the Green Super Rice Project, which aims to diversify breeding targets beyond yield improvement alone to address global concerns around resource use and environmental change.  It is hoped that this review will facilitate further improvement of rice production into the future.

Myo-inositol-1-phosphate synthase (MIPS) is a key rate limiting enzyme in the de novo biosynthesis of myo-inositol in plants. In the present study, the IbMIPS1 gene was introduced into sweetpotato cultivar Xushu 18 and the transgenic plants exhibited significantly enhanced salt tolerance compared with the wild-type (WT). Overexpression of IbMIPS1 up-regulated the salt stress responsive genes, including myo-inositol monophosphatase (MIPP), pyrroline-5-carboxylate synthase (P5CS), pyrroline-5-carboxylate reductase (P5CR), psbA, phosphoribulokinase (PRK), and superoxide dismutase (SOD) genes, under salt stress. Inositol and proline content, SOD and photosynthesis activities were significantly increased, whereas malonaldehyde (MDA) and H2O2 contents were significantly decreased in the transgenic plants. These findings suggest that the IbMIPS1 gene may enhance salt tolerance of sweetpotato by regulating the expression of salt stress responsive genes, increasing the content of inositol and proline and enhancing the activity of photosynthesis.

Intact and steam-flaked grains of maize, wheat and rice (with whole hulls) were analyzed for chemical composition, starch gelatinization degree (SGD) and in vitro fermentation characteristics to investigate the influence of cereal type and steam-flaking (SF) processing on their nutritive values. The treatments were arranged in a 3×2 factorial design. Obvious differences (P<0.001) in chemical composition and energetic values were observed among the different cereal types. SGD and gas production (GP) rate was significantly increased (P<0.001) by SF processing. SF processing also increased (P<0.01) the proportion of propionic acid and decreased the acetic:propionic acid ratio in vitro. Steam-flaking also increased organic matter digestibility and the energetic value of the cereal grains, especially rice. Based on these results, rice probably is more amendable to SF processing than maize and wheat. In conclusion, it is feasible to partially substitute maize grain with wheat or rice in ruminant diets, and steam-flaking can significantly improve the nutritional value of wheat and rice grains.

Trehalose plays an important role in metabolic regulation and abiotic stress tolerance in a variety of organisms. In plants, its biosynthesis is catalyzed by two key enzymes: trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP). In the present study, a TPS gene, named IbTPS, was first isolated from sweetpotato (Ipomoea batatas (L.) Lam.) cv. Lushu 3 by rapid amplification of cDNA ends (RACE). The open reading frame (ORF) contained 2 580 nucleotides encoding 859 amino acids with a molecular weight of 97.433 kDa and an isoelectric point (pI) of 5.7. The deduced amino acid sequence showed high identities with TPS of other plants. Real-time quantitative PCR analysis revealed that the expression level of IbTPS gene was significantly higher in stems of Lushu 3 than in its leaves and roots. Subcellular localization analysis in onion epidermal cells indicated that IbTPS gene was located in the nucleus. Transgenic tobacco (cv. Wisconsin 38) plants over-expressing IbTPS gene exhibited significantly higher salt tolerance compared with the control plant. Trehalose and proline content was found to be significantly more accumulated in transgenic tobacco plants than in the wild-type and several stress tolerance related genes were up-regulated. These results suggest that IbTPS gene may enhance salt tolerance of plants by increasing the amount of treahalose and proline and regulating the expression of stress tolerance related genes.

Transgenic insect-resistant cotton is being increasingly planted in Xinjiang cotton-planting regions, where geographical climate conditions and species composition of pests and natural enemies are greatly unique in China. Limited studies have been conducted on the ecological impacts of transgenic insect-resistant cotton, especially for transgenic double genes (Bt+CpTI) cotton, in this region. In this study, the potential effects of transgenic Bt+CpTI cotton on the seasonal abundance of non-target pests and predators were assessed from 2009 to 2011 in Korla, Xinjiang. The results showed that species composition and seasonal abundance of 5 groups of pests and 5 groups of predators were not significantly different between transgenic Bt+CpTI cotton and non-transgenic cotton every year. It suggests that transgenic Bt+CpTI cotton per se does not affect the population dynamics of non-target pests and predators on this crop in Xinjiang.

Plant height (PH), primary lateral branch length (PBL) and branch number (BN) are architectural components impacting peanut pod yield, biomass production and adaptivity to mechanical harvesting.  In this study, a recombinant inbred population consisting of 181 individual lines was used to determine genetic controls of PH, PBL and BN across three environments.  Phenotypic data collected from the population demonstrated continuous distributions and transgressive segregation patterns.  Broad-sense heritability of PH, PBL and BN was found to be 0.87, 0.88 and 0.92, respectively.  Unconditional individual environmental analysis revealed 35 additive QTLs with phenotypic variation explained (PVE) ranging from 4.57 to 21.68%.  A two-round meta-analysis resulted in 24 consensus and 17 unique QTLs.  Five unique QTLs exhibited pleiotropic effects and their genetic bases (pleiotropy or tight linkage) were evaluated.  Joint analysis was performed to estimate the QTL by environment interaction (QEI) effects on PH, PBL and BN, which collectively explained phenotypic variations of 10.80, 11.02, and 7.89%, respectively.  We identified 3 major and stable QTL regions (uq9-3, uq10-2 and uq16-1) on chromosomes 9, 10 and 16, spanning 1.43-1.53 Mb genomic regions.  Candidate genes involved in phytohormones biosynthesis, signaling and cell wall development were proposed to regulate these morphological traits.  These results provide valuable information for further genetic studies and development of molecular markers applicable for peanut architecture improvement.