Genome-wide association study of grain hardness and novel Puroindoline alleles in common wheat.

Grain hardness (HI) is a key trait for wheat milling and end-use quality. Puroindoline genes (PINs) are the major genes responsible for grain hardness, but other QTLs also contribute to the trait. Therefore, it is essential to identify loci associated with the HI and allelic variations of PINs in wheat. In the present study, 287 accessions from Shanxi province representing 70 years of wheat breeding were grown in one rainfed and two irrigated conditions to study grain hardness. Genome-wide association analysis (GWAS) was performed using the 15 K array, and the variability of PIN alleles was investigated. Among the accessions, hard wheat was most common. The broad-sense heritability (H2) among the three environments was 99.5%, suggesting HI was mainly affected by heredity. GWAS identified nine significant marker-trait associations (MTAs), including that PINs, which explained 7.03% to 17.70% of phenotypic variation. Four MTAs on chromosome 2A, 2B, 5A, and 7A were novel loci. As for diversity of PINs, a total of 11 PINs haplotypes were detected, composed of 12 allelic variations of the PIN gene. The most frequent haplotypes were Pina-D1a/Pinb-D1b (43.9%) and Pina-Dla/Pinb-D1p (18.8%), and both the frequency of Pina-D1a/Pinb-D1b and the HI value increased with breeding years were related to local dietary habits probably. A novel double deletion allele of the PINs haplotype was found in Donghei1206. These results will be useful not only in understanding of the genetics of the HI but also in breeding for improved grain texture. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01303-x.

Design and field experiment of Codonopsis pilosula film covering transplanter.

To address the low efficiency and high labor demands of manual Codonopsis pilosula cultivation, as well as the limitations of existing flat-type transplanting machines that create trenches of inconsistent depth hindering root growth and seedling emergence, a C. pilosula film-covered outcrop tilted transplanting machine was developed. Based on theoretical analysis of the prototype's key components and agronomic requirements for oblique C. pilosula transplanting, the structure and working parameters of the rotary tiller soil throwing device, soil lifting device, track-type soil conveying device, seedling throwing device, and film covering device were determined. The core components' working principles were analyzed, and the soil throwing process of the rotary tiller device was simulated using the discrete element method (DEM). A calculation domain was established, and the results showed that the average mass of the rotary tiller device was 49.44 kg, while the required soil lifting amount for the scraper-type soil lifting device was 21.84 kg, meeting the soil throwing requirements. Field experiments in 10 test areas demonstrated an average qualified rate of 89.50% for planting depth, 84.00% for planting posture, 90% for exposed plant spacing, 4.51 cm for plant spacing, and 8.67% coefficient of variation for planting spacing. These results meet industry standards for planting depth and planting spacing, confirming the machine's effectiveness in achieving high-quality tilted transplanting of C. pilosula seedlings.

The addition of organic fertilizer can reduce the dependence of dryland yield on rainfall-based on a 32-year long-term study.

Clarifying the synergistic effect between rainfall and fertilization in rainfed farming and joint effect on crop yield can provide theoretical basis for improving the sustainable productivity of farmland in dry farming. A 32-year fertilizer regulation experiment was conducted in the dry farming region of the Loess Plateau. According to the precipitation, it was divided into dry, normal and high rainfall years. The influence of long-term fertilization regulation on crop yield and farmland moisture changes under different rainfall years was analyzed, and the regulation mechanism of fertilization and precipitation coordination on crop yield under different rainfall years was explored. The results showed that effects of fertilization on crop yield and water use efficiency (WUE) were closely related to experimental years. In the early stage, the increase in treatments with higher amounts of nitrogen was more significant, while in the later stage, the increase in treatments with less organic fertilizer was more significant. The correlation of crop yield, the whole rainfall (WR), growth period rainfall (GPR), fallow period rainfall (FPR), water storage during sowing (SWS), evapotranspiration (ET), WUE and utilization efficiency of precipitation (PUE)under different rainfall years and treatments was analyzed. The results showed that the crop yield showed that the correlation with PUE showed high> dry> normal rainfall year, and the correlation with WUE showed the law of dry> high> normal rainfall year. The correlation of organic fertilizer treatments was lower than that of single chemical fertilizer. With the years extension of application organic fertilizer, application low amount of organic fertilizer can improve crop yield by improving PUE, and can achieve the effect of application high amount of organic fertilizer. No matter what the rainfall years, the long-term application of organic fertilizer can make full use of the rainfall to improve the WUE, and then ensure the sustainability of crop yield.

Effects of exogenous auxin on yield in foxtail millet (Setaria italica L.) when applied at the grain-filling stage.

Foxtail millet (Setaria italica L.) is of high nutritious value, which is an important crop in arid and semi-arid regions. The objective of this experiment was to explore the effects of the synthetic auxin naphthalene acetic acid (NAA) on the physiological processes of foxtail millet, and to provide a theoretical basis and technical approaches for its efficient use in millet cultivation. Two foxtail millet varieties ('Jingu 21' and 'Zhangzagu 5') were treated with six concentrations of NAA from 0-144 mg L-1 at the grain-filling stage in field experiments. The photosynthetic pigment contents, gas exchange parameters, chlorophyll fluorescence parameters, and grain yield were measured in foxtail millet. The results showed that low concentrations of NAA (18-36 mg L-1) increased the contents of photosynthetic pigments, and increased the activities of antioxidant enzymes, the photosynthetic rate, and the activity of photosystem system II (PS II). At higher NAA concentrations, the facilitation effect of the treatments diminished, showing a clear concentration effect. In this study, yield was significantly and positively correlated with PS II effective quantum yield (Y(II)) and the PSII electron transport rate (ETR), and the net photosynthetic rate (Pn) was significantly and positively correlated with chlorophyll content, stomatal conductance (Gs), Y(II), and ETR. These results also indicated that exogenous NAA application promotes the production of ATP and NADPH by increasing the efficiency of electron transfer within the photosystems and also improved photochemical utilization, which facilitates the fixation and reduction of carbon, ultimately leading to an increase in Pn and increasing grain yield in foxtail millet.

Folate (vitamin B9) content analysis in bread wheat (Triticum aestivum L.).

Vitamin B9, particularly folic acid, is an essential molecule for human health. Wheat flour is one of the major sources of calorie intake by humans. The selection of folate-rich genotypes in wheat breeding can enhance the natural folate value in the daily diet. This study used a precise, high-performance liquid chromatography (HPLC) assay to analyze folate content in a 262-accession Chinese wheat mini-core collection (MCC) grown under three environments. Four folate derivatives in grains including tetrahydrofolate (THF), 5-methyltetrahydrofolate (5-CH3-THF), 5-formyltetrahydrofolate (5-CHO-THF), and 5,10-methenyltetrahydrofolate (5,10-CH+THF) were considered. An association analysis of water regimes, accession types, released years, geographical origin, and agronomic traits with folate content was conducted for the first time. There was a large amount of variation in folate content in the analyzed accessions, with genotype identified as the main influencing factor. Total folate content was significantly correlated with the content of the four MCC derivatives under the three environments. 5-CH3-THF and 5-CHO-THF were the most abundant among the four folate derivatives and were positively correlated with high folate content. The 12 accessions with the highest folate content showed an average of more than 80 µg/100 g. The analysis demonstrated that this Chinese wheat had not undergone extensive selection for folate content during breeding, which is unrelated to the geographical origin, accession types, winter/spring types, and grain colors of wheat. The content of THF, 5-CH3-THF, and 5,10-CH+THF was significantly negatively correlated with grain width, grain thickness, and thousand kernel weight. A relatively weak negative relationship manifested between folate contents and flowering date, whereas no significant correlation with tiller number, grain number per spike, maturity date, height, and spike length was detected. The investigation benefits wheat breeders for folate enhancement.

Genome-wide association study of coleoptile length with Shanxi wheat.

In arid and semi-arid regions, coleoptile length is a vital agronomic trait for wheat breeding. The coleoptile length determines the maximum depth that seeds can be sown, and it is critical for establishment of the crop. Therefore, identifying loci associated with coleoptile length in wheat is essential. In the present study, 282 accessions from Shanxi Province representing wheat breeding for the Loess Plateau were grown under three experimental conditions to study coleoptile length. The results of phenotypic variation indicated that drought stress and light stress could lead to shortening of coleoptile length. Under drought stress the growth rate of environmentally sensitive cultivars decreased more than insensitive cultivars. The broad-sense heritability (H 2) of BLUP (best linear unbiased prediction) under various conditions showed G × E interaction for coleoptile length but was mainly influenced by heredity. Correlation analysis showed that correlation between plant height-related traits and coleoptile length was significant in modern cultivars whereas it was not significant in landraces. A total of 45 significant marker-trait associations (MTAs) for coleoptile length in the three conditions were identified using the 3VmrMLM (3 Variance-component multi-locus random-SNP-effect Mixed Linear Model) and MLM (mixed linear model). In total, nine stable genetic loci were identified via 3VmrMLM under the three conditions, explaining 2.94-7.79% of phenotypic variation. Five loci on chromosome 2B, 3A, 3B, and 5B have not been reported previously. Six loci had additive effects toward increasing coleoptile length, three of which are novel. Molecular markers for the loci with additive effects on coleoptile length can be used to breed cultivars with long coleoptiles.

Analysis of Genetic Regions Related to Field Grain Number per Spike From Chinese Wheat Founder Parent Linfen 5064.

Wheat founder parents have been important in the development of new wheat cultivars. Understanding the effects of specific genome regions on yield-related traits in founder variety derivatives can enable more efficient use of these genetic resources through molecular breeding. In this study, the genetic regions related to field grain number per spike (GNS) from the founder parent Linfen 5064 were analyzed using a doubled haploid (DH) population developed from a cross between Linfen 5064 and Nongda 3338. Quantitative trait loci (QTL) for five spike-related traits over nine experimental locations/years were identified, namely, total spikelet number per spike (TSS), base sterile spikelet number per spike (BSSS), top sterile spikelet number per spike (TSSS), fertile spikelet number per spike (FSS), and GNS. A total of 13 stable QTL explaining 3.91-19.51% of the phenotypic variation were found. The effect of six of these QTL, Qtss.saw-2B.1, Qtss.saw-2B.2, Qtss.saw-3B, Qfss.saw-2B.2, Qbsss.saw-5A.1, and Qgns.saw-1A, were verified by another DH population (Linfen 5064/Jinmai 47), which showed extreme significance (P < 0.05) in more than three environments. No homologs of reported grain number-related from grass species were found in the physical regions of Qtss.saw-2B.1 and Qtss.saw-3B, that indicating both of them are novel QTL, or possess novel-related genes. The positive alleles of Qtss.saw-2B.2 from Linfen 5064 have the larger effect on TSS (3.30%, 0.62) and have 66.89% in Chinese cultivars under long-term artificial selection. This study revealed three key regions for GNS in Linfen 5064 and provides insights into molecular marker-assisted breeding.

Genome-Wide Association Study of Grain Number in Common Wheat From Shanxi Under Different Water Regimes.

Water availability is a crucial environmental factor on grain number in wheat, which is one of the important yield-related traits. In this study, a diverse panel of 282 wheat accessions were phenotyped for grain number per spike (GNS), spikelet number (SN), basal sterile spikelet number (BSSN), and apical sterile spikelet number (ASSN) under different water regimes across two growing seasons. Correlation analysis showed that GNS is significantly correlated with both SN and BSSN under two water regimes. A total of 9,793 single nucleotide polymorphism (SNP) markers from the 15 K wheat array were employed for genome-wide association study (GWAS). A total of 77 significant marker-trait associations (MTAs) for investigated traits as well as 8 MTAs for drought tolerance coefficient (DTC) were identified using the mixed linear model. Favored alleles for breeding were inferred according to their estimated effects on GNS, based on the mean difference of varieties. Frequency changes in favored alleles associated with GNS in modern varieties indicate there is still considerable genetic potential for their use as markers for genome selection of GNS in wheat breeding.

Baicalin promotes cholesterol efflux by regulating the expression of SR-BI in macrophages.

Intake of a high dosage of baicalin has previously been shown to attenuate hyperlipidemia induced by a high-fat diet. Baicalin functions as an activator of peroxisome proliferator-activated receptor-γ (PPAR-γ), which is the key regulator of reverse cholesterol transport (RCT). The present study aimed to test the hypothesis that baicalin could promote cholesterol efflux in macrophages through activating PPAR-γ. Phorbol 12-myristate 13-acetate-stimulated THP-1 cells were treated with oxidized low-density lipoprotein and (3H)-cholesterol for 24 h, and the effects of baicalin on cholesterol efflux were evaluated in the presence of apolipoprotein A-1 (ApoA-1), or high-density lipoprotein subfraction 2 (HDL2) or subfraction 3 (HDL3). The expression levels of scavenger receptor class B type I (SR-BI), PPAR-γ and liver X receptor-α (LXRα) were detected and specific inhibitors or activators of SR-BI, PPAR-γ and LXRα were applied to investigate the mechanism. Treatment of THP-1 macrophages with baicalin significantly accelerated HDL-mediated, but not ApoA-1-mediated cholesterol efflux. However, baicalin treatment increased the expression of SR-BI at the mRNA and protein levels in a dose- and time-dependent manner, and pre-treatment with the SR-BI inhibitor BLT-1 and SR-BI small interfering RNA significantly inhibited baicalin-induced cholesterol efflux. Furthermore, baicalin increased the expression of PPAR-γ and LXRα, and the application of specific agonists and inhibitors of PPAR-γ and LXRα changed the expression of SR-BI, as well as cholesterol efflux. It may be concluded that baicalin induced cholesterol efflux from THP-1 macrophages via the PPAR-γ/LXRα/SR-BI pathway.