Rice is one of the most important crops in China and even the world. Plant type is an important agronomic trait of rice, which is closely related to yield, quality, and stress resistance. Plant type improvement has played an important role in rice breeding in the past, and will have a profound impact on rice breeding in the future. On the base of related achievements of Rice Research Institute of Shenyang Agricultural University, this paper comprehensively reviewed the research progress of rice plant type from the aspects of the concept of plant type, physiological ecology, and genetic basis of plant type breeding, and also discussed the existing problems and development direction of rice plant type. With the application of the latest research results of modern molecular biology, analyze the relationship between various organs and their optimal combination among population and individual, define the physiological ecology basis and the molecular regulatory network, and apply to plant type breeding practice, which is expected to achieve a higher level of “ideal plant type breeding” of rice.

Heat stress is an essential factor affecting maize growth and yield formation. The exploration and mechanism analysis of related tolerance genes is an important field for breeding maize heat stress tolerant varieties. However, there is few study in this aspect. In this study, we identified a nuclear factor ZmNF-YC13 associated with heat stress response, and its encoding gene expression was rapidly induced by high temperature and osmotic stress. The promoter of Arabidopsis thaliana heat stress-inducible expression gene AtHSP70 was used to drive ZmNF-YC13 and the heat-inducible expression maize material of ZmNF-YC13 (HSP21Pro:ZmNF-YC13-myc) was successfully screened. Phenotypic analysis after high temperature treatment demonstrated that leaf length, leaf width, shoot thickness, fresh and dry weight of shoot and root were significantly higher than wild type. The relative expression level showed that ZmNF-YC13 could enhance the inducible level of downstream heat stress response genes in response to heat stress. Luciferase reporter assay and ChIP-qPCR assay also revealed that ZmNF-YC13 could regulate the expression of heat stress transcription factor ZmHsfA2c. These results confirmed preliminarily that ZmNF-YC13 could improve the heat tolerance of maize by regulating downstream heat stress response genes, which could provide a theoretical basis for marker-assisted selection and germplasm identification using the polymorphism of this locus.

To establish a system for rapid identification of millet gene functions, in this study, we compared the effects of explants from different foxtail millet cultivars, the concentrations of acetyleugenone, bacterial solution, and co-culture time on the hairy root induction mediated by Agrobacteria rhizogenes strain K599. When the shoot tips were infected with bacterial solution 0.5 optical density (OD) and containing 100 μmol L^-1 acetyleugenone, and co-cultured for three days, the induction efficiency of hairy roots reached to 80.24%. Using this system, we analyzed the transformation efficiency of the hairy roots, the subcellular localization of SiDVL1and SiDVL3, and gene functions of SiNHX2, SiCBL4, and SiCBL7. The PCR results of GFP gene and GFP fluorescence microscopic observation indicated that the transformation efficiency of the hairy roots was over 70%. The subcellular localization of SiDVL1 and SiDVL3 was similar in millet hairy-root and tobacco epidermal cells. Simultaneously, the survival rates of SiNHX2, SiCBL4, and SiCBL7 transgenic millet were significantly higher than that of empty vector transformed millet. Therefore, our study established an efficient and rapid method to analyze the subcellular location and to identify the function of genes from foxtail millet.

It is well-known that LRRII-RLK gene family widely exists in plants. These genes are receptor like kinase (RLK), which play a significant role in plant development and biological stress. Up till now, there is no systematic identification and analysis of the LRRII-RLK gene family in sugarcane. Here, we identified 27 LRRII-RLK genes in Saccharum spontaneum, which were distributed on 17 chromosomes. Phylogenetic tree showed the classification of these genes into three different branches including NIK, SERK, and LRRII-C. Furthermore, we observed the significant amplification in the LRRII-C branch. Next, we characterized the cis-regulatory elements, which identified 32 different types of cis elements in the gene promoters, primarily involved in light response, stress response, regulation of hormone mechanism, and plant growth. Interestingly, SsLRRII-RLK genes were detected to be conserved with 35 collinear gene pairs and multiple conserved motifs. These genes were mainly amplified by segmental replication and had undergone strict purification selection during the evolution, according to their K_a/K_s ratios. Furthermore, the relative expression level of SsLRRII-RLK genes varied in different tissues of sugarcane. Additionally, some genes expressed differently during distinct periods of day and night, suggesting that they were associated with plant growth regulation and photosynthesis. Noticeably, the relative expression pattern of SsLRRII-RLK genes varied significantly under different disease conditions (sugarcane pokkah boeng disease and mosaic disease). In conclusion, these genes might play a role in pathogenesis and viral replication. The results of this study are helpful to further understand the evolutionary process of LRRII-RLK gene in sugarcane. This data provides a preliminary theoretical basis for the functional study of LRRII-RLK gene during photosynthesis, growth and development, and disease conditions in sugarcane.

Sweetpotato is a heliophile crop. However, it is usually shaded in the lower position in the interplanting cultivation mode. During the middle and late field growing period, it often faces rainy weather with little illumination, which affects the dry matter accumulation in tuberous roots. Thus, analyzing the metabolic response pathways of sweetpotato under shade stress will provide the theoretical basis for the varieties’ genetic improvement of shade tolerance. In this study, the sweetpotato variety Zhenghong 23 was exposed to shade stress with 50% light transmittance for 15 days. Results showed that chlorophyll b and the total chlorophyll contents of Zhenghong 23 under shade stress were significantly increased compared with those under natural light. The maximum photochemical efficiency (F_v/F_m), the potential activity (F_v/F_o), and the comprehensive index of photosynthetic performance (PI_ABS) of the chlorophyll photosystem PSII decreased significantly under shade stress. The net photosynthetic rate and water use efficiency decreased significantly, while SOD and POD enzyme activities increased significantly. In addition, shade stress increased significantly the vine length and specific leaf area of Zhenghong 23, but reduced significantly the fresh weight of roots. Transcriptome and metabolome analysis of leaf tissues under shade stress and natural light conditions showed that the DEGs and DMs were mainly enriched in phenylpropanoid biosynthesis, sugar metabolism, sphinolipid metabolism, and arginine biosynthesis pathways. Most of the up-regulated DEGs enriched in the phenylpropanoid biosynthesis pathway were POD enzyme family genes, indicating that the shade stress triggered the ROS scavenging system in sweetpotato. Meanwhile, shade stress reduced sugar metabolism level of sweetpotato, decreased the soluble sugar content of leaves, inhibited both the synthesis and degradation of starch, and blocked the expansion of tuberous roots. In addition, the sphinolipid and arginine metabolism pathways may better adapt sweetptoato plants to shade stress through improving the stability of biomembranes and increase the synthetic substrates of polyamine anti-stress factors. These results provide new theoretical basis for understanding the metabolic response pathways of sweetpotato under shade stress.

In order to establish a system for extracting nuclei and constructing library of assay for transposase accessible chromatin with high-throughput sequencing (ATAC-seq) in gramineous plants, the leaves and roots of rice, wheat, and zoysia were used as the research materials. The best method to extract nuclei was determined by designing control variable experiments: grinding samples with liquid nitrogen, selecting 1200×g centrifugal stress for extracting initial nuclei, using ORB buffer twice and SCB buffer to purify nuclei. It was suggested that the extracted nuclei were suitable for the sequencing of transposase accessible chromatin and high-quality sequencing data could be obtained by testing. In summary, an integrated system suitable for gramineous plants to extract nuclei had been established. This method will lay a foundation for obtaining the information of chromatin accessible regions and the regulation of gene expression in gramineous plants.

In recent years, due to the frequent occurrence of extreme weather, low temperatures (LT) became one of the main disasters restricting wheat production. LT has negative effects on wheat growth and yield formation, especially at booting stage. Exogenous spraying of 6-benzylamino adenine (6-BA) after LT at booting stage can alleviate the damage caused by LT in wheat, but the related molecular regulation mechanism is still unclear. In this study, transcriptome sequencing technology was used to analyze the molecular mechanism of 6-BA improving cold tolerance in wheat. The LT sensitive variety Wanmai 52 and insensitive variety Yannong 19 were selected as the experimental materials. The experiment was carried out in combination of potted and field planting. Two wheat cultivars were planted in plastic pots at a planting density of ten plants per pot. At booting stage, the pots were moved into an artificial climate chamber for low temperature treatment. At the end of the treatment, 20 mg L^-1 6-BA solution was sprayed, and an equal volume of distilled water was sprayed as the control. The morphology of young spike, and the content of soluble sugar and starch in young spikes were determined. Some candidate differentially expressed genes (DEGs) were screened and their relative expression patterns were analyzed by qRT-PCR, and the results were verified by qRT-PCR. After 10 days, compared with the control, the morphological development of young spike was better, fuller and longer. The contents of soluble sugar and starch in young spikes increased after 6-BA treatment. The results showed that 22,770 DEGs were identified in Wanmai 52 and 9866 in Yannong 19, respectively, and 661 genes were up-regulated in the two cultivars. ARF5, AGPL1, 1-SST, SWEET15, and other genes were screened out, which were related to the regulation of plant hormone level, starch synthesis, and sugar metabolism. GO and KEGG enrichment analysis were performed on the selected differential genes. GO annotation revealed that the functions of the differential genes of the two varieties were mainly concentrated in cell structure stability, metabolism, and catalytic activity. KEGG enrichment analysis demonstrated that signal transduction, regulation of endogenous hormone levels, carbon metabolism, the changes of membrane structure and function had significant changes. In conclusion, 6-BA could alleviate cold damage by regulating the metabolism of antioxidant substances, hormone signal transduction, carbohydrate metabolism, osmotic adjustment, and other ways in wheat. The results provide a theoretical basis for exploring the cultivation measures to reduce the damage of low temperature on wheat in spring.

Transgenic maize ND207 is an insect-resistant maize with mCry1Ab and mCry2Ab genes developed by China Agricultural University. The objective of this study is to develop the event-specific PCR detection method for ND207. The PCR amplification was performed according to the primers provided by the ND207 developer. The sequence of insertion site of ND207 was sequenced and obtained 262 bp of the 5'-flanking sequence, including 109 bp vector sequence and 153 bp maize genome sequence, 316 bp of the 3'-flanking sequence, including 76 bp vector sequence and 240 bp maize genome sequence. Fourteen primers were designed at both ends to form 25 primer pairs. The best primer pair at the 3' end was selected to optimize the PCR reaction system and reaction condition. The event-specific qualitative PCR detection method of ND207 was established and the PCR product size was 166 bp. After testing, the results showed that the detection limit of this method was 0.1%, equivalent to 20 copies of ND207 specific molecule fragment. Eight GMO safety testing institutions in China tested specificity, detection limit, reproducibility of the method, and the circular verification report revealed that the method met the requirement of the national standard method, which could be promoted and applied in the testing industry. The established event-specific qualitative PCR detection method of ND207 provides the technical support for the safety supervision of ND207 and its derivatives in China.

Chlorophyll is a kind of green pigment for plant photosynthesis, which has a direct effect on plant growth. In this study, bioinformatics methods were used to identify the members of SGR gene family in Brassica napus, Brassica rapa, Brassica oleracea, and Arabidopsis thaliana. Most of the 28 SGR genes contained four exons, encoding basic proteins. Chromosome mapping and syntenic analysis showed that there was no tandem duplication in the SGR gene family members of Brassica napus. SGR gene family members had a linear relationship, highly homologous in evolution, and very conserved in the evolutionary process. Moreover, a genome-wide association study (GWAS) of chlorophyll content was performed using a Brassica 60K Illumina Infinium SNP array in 203 Brassica napus accessions. Two haplotype regions (Chr.A01: 6,193,165-6,317,757 bp and Chr.C01: 9,059,861-9,906,618 bp) carrying two SGR genes (BnaSGR1a-A01 and BnaSGR1-C01) were detected, which were significantly associated with chlorophyll content. Meanwhile, the regional association analysis of 50 resequenced rapeseed inbred lines revealed that a SNP located in exon 2 of BnaSGR1a-A01 significantly associated with chlorophyll content. Co-expression network analysis revealed that BnaSGR1a-A01 were directly linked with BnaSGR2-A03, and indirectly linked with BnaSGR1-C01, BnaSGR1-A08, BnaSGR2-C03, BnaSGR1-C07, BnaSGRL-C06, and BnaSGRL-A10, thus forming a molecular network involved in the potential regulation of chlorophyll content. Chlorophyll a, chlorophyll b, and the total chlorophyll content of T₂ Arabidopsis transgenic plants overexpressing BnasSGR1a-A01 were significantly lower than wild type, indicating that BnaSGR1a-A01 regulated chlorophyll degradation. This study laid a foundation for the functional research and utilization of SGR gene in Brassica napus L.

Geraniol is an important volatile monoterpene alcohol contained in tea plant, which plays an important role in the interaction between tea plant and environment and constitutes one of key aroma components in tea. Geraniol from tea plant tender shoots mainly exists in the form of geranyl β-primeveroside. Explore SNP loci and candidate genes significantly associated with geranyl β-primeveroside content is of great significance for the the genetic regulation mechanism of geranyl β-primeveroside content and tea plant genetic improvement. Regarding 169 tea germplasms as the research materials, the geranyl β-primeveroside content of tea plant tender shoots was identified for three consecutive years (three environments), and the SNP markers were developed based on SLAF-seq technology. Then, the geranyl β-primeveroside content of tea plant tender shoots was analyzed by genome-wide association analysis (GWAS) using general linear model (GLM). The candidate genes were further screened based on the SNP loci significantly with the geranyl β-primeveroside content. Ultimately, the base differences of candidate gene coding regions and their upstream cis acting elements among the extreme geranyl β-primeveroside content were analyzed. Results showed that the variation coefficient of geranyl β-primeveroside content in three environments ranged from 77.6% to 81.8%, and the broad heritability was 62.6%. The geranyl β-primeveroside content was significant differences among the genotypes and environments, and the variation was mainly affected by heredity. A total of 340 SNP markers significantly correlated with the geranyl β-primeveroside content were detected under three environments, in which 65 SNP markers were detected repeatedly under 2 environments. Based on the tea plant reference genome and linkage disequilibrium decay distance, a total of 88 genes within 100 kb on both sides of the repeated 65 SNP markers were obtained, including signal proteins, kinases, phosphatases, ion transporters, transcription factors, heat shock proteins, hormone related proteins, resistance proteins, terpene metabolic enzymes, glycosyltransferases, and glycosidases. 10 candidate genes were preliminary screened out. SNP nonsynonymous mutations in the coding region sequences of 10 candidate genes between two extreme geranyl β-primeveroside content materials, and different numbers of cis acting elements related to environmental stress and hormones in the upstream 2 kb regions of most candidate genes were discovered. This study provides a new perspective for clarifying the genetic regulation mechanism of geranyl β-primeveroside content in tea plant tender shoots, and also provides the markers and gene resources for molecular marker assisted selection of new tea varieties.

Light-induced greening of tubers seriously affects its safety and economic benefits, but the mechanism of light-induced chlorophyll synthesis in potato tubers remains unclear. In this study, the related metabolites of potato tubers with different light durations were analyzed. The results were as follows: When the light duration prolonged, the chlorophyll content of the tubers gradually increased. Moreover, the chlorophyll content increased significantly at 36 hours, with which the tuber skin turned green obviously. Transcriptome sequencing and bioinformatics analysis were carried out on the samples taken at 0 hour, 6 hours, and 36 hours, and 5646 differentially expressed genes (DEGs) were identified. According to the co-expression cluster analysis and quantitative RT-PCR verification results, 9 major structure genes of chlorophyll biosynthesis pathway (StGAS1, StCHLD, StCrd1, StHEMA, StGUN4, StPORA, StUROD, StCHLM, and StCHLG) and 6 transcription factors (StSBP, StLSD, StGATA, StWRKY, StMYB-like, and StMYB113) were significant induced. Predictions of the cis-acting elements of the promoter sequences of these 9 structural genes indicated that they all contained multiple MYB binding sites. Promoter element analysis and transcriptional activation validation further revealed that StMYB113 had a light-responsive element and could activate the expression of StUROD in tobacco. Therefore, StMYB113 may be light-responsive and be able to regulate potato tuber greening in the light. This study provides a reference for the research on the regulatory mechanism of light-induced chlorophyll synthesis in potato tubers, which is important for reducing the loss caused by greening of potato tubers.

Fava beans (Vicia faba L.) is an important food bean crop, and drought can lead to lower fava bean yields. The identification of drought tolerance genes of fava beans is beneficial to breed the drought-resistant varieties through molecular marker-assisted breeding and genetic engineering. In a previous study, we identified a class of aspartate aminotransferase genes (ASPAT) in response to faba bean drought stress by transcriptome sequencing. ASPAT catalyzes the reversible reaction of transamination between aspartate and α-oxoglutarate to generate oxaloacetate and glutamate, and plays a key role in plant metabolism. Based on transcriptomic sequencing data, ASPAT members were identified in genome-wide level. The physicochemical properties, subcellular localizations, gene structures, protein domains, conserved motifs, phylogeny, protein interaction, and gene expression patterns of each member were analyzed. The results indicate that eight ASPAT genes were identified from the transcriptomes, which included three eukaryotype ASPAT (AAT) genes and five prokarytoype ASPAT (PAT) genes with mitochondria and chloroplast location, respectively. Phylogenetic analysis showed that ASPAT could be divided into two subfamilies Iα and Iβ. Iα is AAT protein including VfASPAT1-VfASPAT3, and Iβ is PAT protein consisting of VfASPAT4-VfASPAT8. ASPAT family members of Vicia faba contain motif 1, motif 3, and motif 9, and had similar gene structures and common protein domain aminotran-1-2. VfASPATs protein interaction network suggested that the members might be involved in stress metabolism. Transcriptome and qRT-PCR indicated that he expression patterns of the eight members were different at 16 hours and 64 hours under drought stress. All the members were up-regulated with the exception of VfASPAT4 and VfASPAT6, implying that VfASPATs may have a positive regulation effect on drought stress. In this study, eight ASPAT genes of Vicia faba were identified, and the structures, distribution, evolutionary relationship, and the relative expression patterns of ASPAT gene family members were analyzed. The results of this study laid a foundation for further analysis of drought resistance function of VfASPATs, and the application of ASPAT to improve drought resistance of fava bean.

Cyperus esculentus is a new industrial crop with the high comprehensive utilization value, which is a strongly resistant to stresses and has a great potential to grow in saline soil. In order to clarify its salt tolerance, five NaCl concentrations (0, 0.3%, 0.6%, 0.9%, and 1.2%) were set in this study to analyze the effects of NaCl stress on morphological and physiological indexes during germination and seedling growth. The results showed that the germination percentage, root length, and seedling height were less affected under 0.3% and 0.6% NaCl stresses. Meanwhile, the contents of indicator of membrane damage degree, malondialdehyde (MDA), and oxidative stress substance, hydrogen peroxide (H₂O₂), did not increase significantly. However, the contents of osmoregulation substances [glycine betaine (GB), and proline (Pro)] and the activities of antioxidant enzymes [superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)] were significantly increased, and the damage of salt stress was less on the whole. However, under 0.9% and 1.2% NaCl stresses, the salt stress injury was very obvious and the germination and seedling growth of Cyperus esculentus were severely inhibited. In order to further identify the genes related to salt tolerance, RNA-seq technology was used to detect the gene expression in roots under 0, 0.3%, and 0.6% NaCl stresses. 24 GO terms mainly related to oxidoreduction, transmembrane transport, chitin hydrolysis was significantly enriched, among which 15 significantly up-regulated genes were involved, through gene differential expression analysis, weighted gene co-expression network analysis (WGCNA), and GO enrichment analysis. Among them, DN23985_c0_g1, DN2960_c0_g1, and DN8384_c1_g1 encoded zeaxanthin epoxidase, L-ascorbate peroxidase, and glutathione S-transferase, respectively, which had antioxidant effects and participated in antioxidant regulation. Both DN21785_c1_g1 and DN6596_c0_g1 encoded amino acid transporters, which may enhance osmoregulation by accumulating small amino acid molecules such as Pro. DN14393_c0_g1 encoded chitinase, which hydrolyzed chitin and promoted plant response to stress. In this study, it was confirmed that Cyperus esculentus had a good salt tolerance under 0.6% or less NaCl stress, and the salt-tolerance related genes were further screened out, which provided an important reference for the cultivation in saline soil and the breeding of salt-tolerant varieties.

The objective of this study is to clarify the effect of soil water content on wheat grain yield and the physiological reasons for its formation. During the winter wheat growing season from 2019 to 2021, four kinds of soil water content treatments were set under the field conditions of the wheat test station in Shijiawangzi village, Xiaomeng town, Yanzhou district, Shandong province: No-irrigation (W0), and the relative water content of the soil in the 0-40 cm soil layer was supplemented to 65% (W1), 75% (W2), and 85% (W3) at jointing and anthesis stages, and the winter wheat variety was Jimai 22. The effects of soil water content on water consumption, leaf and root senescence, and grain yield of wheat were studied. The results showed that the number of kernel number and 1000-kernel weight of W2 treatment were significantly higher than those of other treatments, and the highest grain yield and water use efficiency were obtained. Compared with W0, W1, and W3, the grain yield was 48.49%, 20.80%, 8.68% (2019-2020) and 46.87%, 17.36%, 7.53% (2020-2021), respectively. The water use efficiency was 21.70%, 14.25%, 15.59% (2019-2020) and 25.44%, 11.90%, 13.39% (2020-2021), respectively. Compared with the other treatments, root length density in the 40-100 cm soil layer, superoxide dismutase activity and root activity in the 40-60 cm soil layer in W2 treatment were significantly higher than those in other treatments after anthesis, and the content of malondialdehyde was significantly lower than those in other treatments. After anthesis, the superoxide dismutase activity of flag leaves in W2 treatment was significantly higher than that in W0 and W1 treatments, but there was no significant difference in W3 treatment, and the content of malondialdehyde was significantly lower than that in W0 and W1 treatments, but there was no significant difference in W3 treatment. W2 treatment increased significantly water consumption, daily water consumption, water consumption model coefficient, and soil water storage consumption in the 40-120 cm soil layer from anthesis to maturity. In conclusion, the appropriate soil moisture content could promote root growth, delay plant aging, and then improve the absorption and utilization of deep soil moisture, ensure the supply of water during grain filling, and improve significantly grain yield in wheat. Under the conditions of this experiment, the effect of W2 treatment was the best when the relative water content of 0-40 cm soil layer was increased by 75% at the jointing and anthesis stages in wheat.

It is of great significance to clarify the effects of cultivars and soil factors on wheat manganese nutrition for optimizing wheat manganese nutrition and achieving high yield and high-quality wheat production. From 2016 to 2020, a field experiment was carried out at 38 test sites in 13 provinces in three wheat production regions: Northwest dry-farming wheat area (DW), Huanghuai wheat-maize rotation area (WM), and Southern rice-wheat rotation area (RW). Wheat yield, yield components, grain Mn concentration, soil available manganese, pH value, and other indicators were tested. Results showed that, wheat yield was in the following order: WM > RW > DW, with the average value of 8.1, 5.9, and 5.9 t hm^-2, respectively. Mn concentration in wheat grains was in the following order: RW > DW > WM, with the average value of 46.9, 45.4, and 41.4 mg kg^-1, respectively. In different wheat production regions, the relationships of grain Mn concentration with the dry matter accumulation distribution, yield components, Mn uptake, and the utilization of wheat cultivars were different. The correlation of grain Mn concentration was significantly negative with the yield, biomass, and harvest index of wheat cultivars in DW, and was significantly negative with yield and harvest index in WM, but not significant in RW. There was a significant negative correlation between wheat grain Mn content and soil pH value, available Cu, and the total N, but not significant correlation between wheat grain Mn content and soil available Mn. Grain Mn concentration was positively correlated with spike number, but significantly negative with 1000-grain weight in RW. Grain Mn concentration was positively correlated with Mn uptake in shoots and Mn uptake in grains in WM and RW, and only positively correlated with Mn uptake in grains in DW, while its correlation with Mn harvest index was significantly negative in RW but positive in DW and WM. The main soil factors affecting wheat grain Mn concentration included soil total nitrogen, pH value, available Fe, available Mn, and available Cu. In WM, the grain Mn concentration was significantly positively correlated with soil available Fe, available Cu and Mn, but negatively correlated with soil pH. In RW, grain Mn concentration was significantly and negatively correlated with soil pH value, available Cu, and the total nitrogen, but not correlated with soil available Mn. Soil available P and available K were the main factors affecting grain Mn concentration in DW. In conclusion, wheat cultivars in RW of China had higher grain Mn concentration. Lower soil pH value, the total nitrogen, and the higher soil available Fe and Mn were beneficial to the increase of grain Mn concentration, while the effects of soil available Cu on grain Mn concentration varied with wheat regions. The yield had a dilution effect on Mn concentration, and the increase of spike number, grain number per spike, and 1000-grain weight were beneficial to the decrease of Mn content in wheat cultivars.

Water shortage and high fertilizer input have become the dominant factors restraining maize production in arid oasis irrigation area, it is urgent to study the technology of stable yield and increasing yield of crops with reduced water and fertilizer. To provide basis for establishing the efficient technology of stable and high yield of maize with water and nitrogen reduction, the effects of increasing density on dry matter accumulation, grain yield and yield components of maize were investigated under reduced water and nitrogen supply. A split-split plot field experiment was conducted in 2020 and 2021. Under two irrigation levels on local conventional irrigation reduced by 20% (W1) and local conventional irrigation (W2), and two levels of nitrogen fertilizer at a local conventional nitrogen reduced by 25% (N1) and local conventional nitrogen (N2), the response characteristics of dry matter accumulation and yield of maize were studied when maize density increased from 75,000 plants·hm^-2 (low density, D1) by 30% (medium density D2), and by 60% (high density D3). The results showed that the grain yield of maize was significantly decreased with the reduced water and nitrogen supply, and increasing planting density by 30% could compensate the negative effect on the decrease of yield. Under the reduced water supply while maintaining N application rate, the dense planting density could significantly increase grain yield. In the two experimental years, the yield of W1 was 3.0% lower than W2. The grain yield of N1 was 12.9% lower than N2. Compared with D1, D2, and D3 increased grain yield by 12.9% and 9.2%, respectively. Compared with W2N2D1, the grain yield of W1N1D1 was decreased by 12.3%, but there was no significant difference between W2N2D1 andW1N1D2 treatments. Under the reduced water and nitrogen supply, increasing density could compensate the negative effect on the decrease of yield was mainly attributed to promoting the dry matter accumulation from early-filling to maturing stage and improving panicle number significantly. Compared with W2N2D1, the dry matter accumulation of W1N1D2 was increased by 5.8% from the early-filling to maturing stage of maize, but there were no significant differences on V_max (maximum rate of dry matter accumulation), V_mean (mean increase rate of dry matter accumulation), T_m (the days of the maximum rate), and HI (harvest index) between W1N1D2 and W2N2D1 treatments. Compared with W2N2D1, the spike number of W1N1D2 was increased by 24.7%, but the number of kernels per spike and 1000-kernel weight of W1N1D2 were decreased by 19.3% and 14.8%, respectively. The grain yield of W1N2D2 was 13.9% higher than W2N2D1. When the nitrogen application rate was unchanged, the main reasons for the reduced irrigation, increasing density, and stable yield were the increase of dry matter accumulation, V_mean, HI, and the panicle number. Compared with W2N2D1, W1N2D2 increased panicle number, dry matter accumulation, V_mean and HI by 24.8%, 10.2%, 8.4%, and 4.7%, respectively, but there was not significant difference in 1000-kernel weight between W1N2D2 and W2N2D1 treatments. In conclusion, increasing planting density by 30% under the simultaneous reduction of water and nitrogen in the experiment was a feasible measure to save water and nitrogen for stable and high yield of maize in oasis irrigation areas. Increasing planting density by 30% was a feasible measure to save water and increase yield of maize when irrigation water was reduced by 20% while maintaining N application rate

Light intensity at grain filling stage is an important ecological factor for high rice yield and quality. To investigate the effects of shading duration on yield and quality of two high yielding (Xindao 41, Jijing 88) and two good quality (Liangjing 10, Jijing 515) Japonica rice cultivars 10 days after heading (DAH10), 20 days after heading (DAH20), heading to maturity (DAHM), and no shading as the control (CK), this experiment was conducted in Urumqi, Xinjiang, China, in 2018 and 2019. The results showed that, shading after rice heading lengthened grain filling duration, and decreased the seed setting rate, 1000-grain weight, and rice yield. The decreasing amylose content and increasing protein content under shading after heading led to an increase in chalky grain rate, degree of chalkiness, and worsened significantly paste property and taste value. Compared to CK, mean seed setting rate and thousand grain weight of DAH10, DAH20 and DAHM decreased by 3.5%, 9.7%, 11.1% and 3.7%, 7.1%, 13.1% respectively, leading to significant decrease in yield during the two years period by 11.3%, 16.5%, and 31.7%, respectively. There was no obvious influence of first ten-day shading after heading on grain amylose content and taste value. The protein content of DAH20 and DAHM in the two years increased by 20.5% and 30.8%, respectively, while amylose content decreased by 3.6% and 4.6%, respectively. This resulted in the decreasing breakdown and taste values by 15.2%, 26.1%, and 3.9%, 7.7% respectively. The effects of shading duration after heading on chalky grain rate varied with the local background light intensity. The increase of 152.1% chalky grain rate occurred in the first ten-day after heading in 2018, while the increase of 345.5% was observed 20 days after heading in 2019. High yield rice cultivars had more sensitivity to shading duration after heading compared to good quality rice cultivars. Decreases of grain filling rate and 1000-grain weight of the high yield cultivars reduced grain yield, while it led to higher chalkiness rate. In conclusion, 20 days of shading after rice heading was the key period to affect the appearance quality in rice, and the shading duration depended on the background light intensity. The longer the shading time, the worse the cooking quality of rice. This study provides a scientific basis for japonica rice production in the future climate change.

The purpose of this study is to explore the effects of different water and nitrogen interaction on yield and processing quality of high-quality wheat with strong gluten Shiluan 02-1, and to provide theoretical basis for how to achieve the goal of synergistically improving grain yield and processing quality through reasonable irrigation and optimal nitrogen application rate in the production of strong gluten wheat. From 2017 to 2020, the two factors split zone experiment of watering times and nitrogen application amount was set under field conditions. The main-plot factor was watering times [spring watering one time (W1, jointing water) and spring watering two times (W2, jointing water + flowering water)]; and the split-plot factor was nitrogen (N) fertilizer treatment in six levels (N0: 0, N1: 60, N2: 120, N3: 180, N4: 240, and N5: 300 kg hm^-2). The study showed that: When N application rate was 0-300 kg hm^-2, the yield of spring irrigating one time and spring irrigating two times increased first and then decreased with the increase of N application rate, and the N application amount corresponding to the maximum grain yield was 240 kg hm^-2 in the different precipitation years. When N application rate was 120-300 kg hm^-2, the yield of spring irrigating two times was significantly higher than that of spring irrigating one time. Water and N interaction had the greatest effect on the number of grains per unit area, followed by 1000-grain weight, which had the least effect on grain number per spike. When N application rate was 0-300 kg hm^-2, the average value of wet gluten content, sedimentation value, water absorption rate, dough stability time, tensile energy, and maximum tensile resistance of winter wheat treated with spring irrigating two times were higher than those treated with spring irrigating one time in 2017 and 2018 (wet year). However, in 2018-2019 and 2019-2020 (drought year), it was opposite: spring irrigating one time was higher than spring irrigating two times. The wet gluten content and sedimentation value of wheat in spring irrigating one time and spring irrigating two times increased first and then decreased or gradually increased with the increase of N application rate in different precipitation years, the N application rate corresponding to the maximum of the two quality indicators was 240 kg hm^-2 or 300 kg hm^-2. The stabilization time, tensile energy, and maximum tensile resistance increased first and then decreased with the increase of N application rate, and reached the maximum value when N application rate was 240 kg hm^-2. The grain yield and processing quality of high-quality wheat with strong gluten Shiluan 02-1 were the best when it was watered twice in spring and N was applied at 240 kg hm^-2 in different precipitation years.

Stem vascular bundle plays an important role in the mechanical supporting and material transportation of crops. To extract the vascular bundle parameters from the crop stem slices, we developed a high-throughput method “LabelmeP1.0”, which combined the image-annotation function of commercial software “Labelme” with the Python programming language. A total of 26 parameters including both the primary and secondary parameters related to stem regions and vascular bundles was generated in 92 sorghum germplasm resources. 15 parameters related to the number, size, location, proportion, and the density of vascular bundle were summarized as the core indexes by correlation analysis and principal component analysis. In addition, the number and the density of vascular parameters were positively related to agronomic traits including panicle weight, grain weight, and number of primary rachis branch. The germplasm resources could be divided into three categories, namely, class I with lower plant height, thicker stem, thinner rind, fewer seeds, and more vascular bundles, in contrast class II with higher plant height, thinner stems, fewer seeds and vascular bundles and, class III with lower plant height, thicker stem, more seeds and vascular bundles. This study provides the methodology and new ideas for the study of the stem anatomical parameters in crops.

To investigate the effect of N application level on grain-filling and starch accumulation in individual sorghum grains, sorghum variety Fenjiuliang 1 was used as the experimental material in 2019 and 2020. Six N rates of 0, 75, 150, 225, 300, and 450 kg N hm^-2 were applied before sowing to experimental plots in Shanxi, China. To analyze sorghum grain-filling and starch accumulation by the Richards’ growth equation, the superior and inferior spikelets were sampled at seven days intervals at each sampling from anthesis to maturity. The rational N application level (75 kg N hm^-2) showed the maximum grain number per panicle resulting in the maximum yield per hectare. For both superior and inferior spikelets, N had similar effects on grain weight, grain morphology structure, the characteristics of grain-filling, and grain starch accumulation. The grain weight, grain volume, and grain-filling rate increased with the increase of N application rate, whereas the maximum grain weight and grain volume was obtained with the zero N treatment. The grain starch accumulation rate was highly correlated with the activity of ADP-glucose pyrophosphorylase (AGPase) and soluble starch synthase (SSS). Compared to the zero N treatment, N application enhanced grain starch accumulation rate at early grain-filling stage and grain-filling rate, which may be due to the increased AGPase and SSS activity at the early grain-filling stage. Compared with rational N (75 kg N hm^-2), excessive N (450 kg N hm^-2) promoted grain starch accumulation by enhancing the activity of AGPase and SSS at the early grain filling stage, whereas zero N application enhanced sorghum grain weight and grain starch accumulation by extending the grain-filling duration and enhancing the activity of key enzymes in grain involved in sucrose-to-starch conversion at the late grain-filling stage.

Industrial hemp is an important natural fiber crop in China. Its main planting areas are richer in copper mines, and the cultivated soil is seriously polluted by copper. Industrial hemp has strong copper tolerance and high biomass and can replace food crops on copper-contaminated soils. It is of great significance to explore how to enhance its copper tolerance. Salicylic acid (SA) plays an important role in plant stress resistance. In this study, to explore the effect of exogenous SA on the copper tolerance and copper enrichment of industrial hemp under copper stress, the copper-sensitive variety Yunma 1 was used as the experimental material. The results showed that copper stress had obvious toxic effects on industrial hemp. Exogenous SA reduced the copper content of hemp fibers and enhanced the absorption and fixation of Cu²⁺ in roots. The copper content in underground and the copper accumulation were 1610.1% and 857.1% in stress group, respectively, which may be achieved by improving the metabolism of hemicellulose and xyloglucan and the activity of glucosidase. Exogenous SA promoted the photosynthesis and dry matter accumulation of industrial hemp under copper stress, enhanced significantly the oxidoreductase activity, decreased ROS and MDA content, and reduced oxidative damage. The application of exogenous SA under copper stress can specifically induce the relative expression level of CsCIPK25 and CsWRKY32, and enhance the tolerance of industrial hemp under copper stress by regulating ion transport, and copper absorption immobilization, and metal chelate synthesis.

Potato is the fourth largest food crop in the world. Two-thirds of the world’s population feed on potato, which is an important target crop for zinc biofortification strategy. It is of great importance to study zinc uptake in potato. Zinc transporters regulate zinc uptake in plants. In this study, we cloned potato zinc transporter StZIP12 on the basis of previous studies. Quantitative PCR results showed that StZIP12 was expressed in all potato tissues, and the relative expression level of StZIP12 in young leaves was significantly higher than that in other tissues. In addition, low zinc treatment could also induce StZIP12 expression. The heterologous yeast complementation test confirmed that StZIP12 could restore the zinc absorption function of ZHY3 (zrt1zrt2) yeast mutant. We obtained StZIP12 overexpressing transgenic plants in cultivar potato Eshu 3 by genetic transformation method. Under zinc deficiency treatment, the overexpression of StZIP12 increased plant height of transgenic plants, root length, and the total zinc content of transgenic seedlings, and the zinc content of tubers of pot-cultured transgenic plants. The zinc content of tubers of two lines was 22.00% and 32.95% higher than that of the control, respectively. These results prove that StZIP12 playes an important role in the absorption of zinc in potato, and provides a theoretical basis for the biofortification of potato zinc.

To explore the effects of N fertilizer rates on seed yield and quality of winter rapeseed, field experiments were carried out in Wuxue County, Hubei Province during 2019/2020 and 2020/2021 seasons. The experiments were set at five nitrogen application levels of 0, 90, 180, 270, and 360 kg N hm^-2. Rapeseed yield, N concentration, and rapeseed quality indexes were measured at maturity stage. The results showed that N application significantly increased rapeseed yield and N content. Compared with the zero N application, the average yield increase after N application was 1548 kg N hm^-2, and the average yield increase rate was up to 32.9%. Within the range of N application rate of 0-270 kg N hm^-2, rapeseed yield increased significantly with the application of N fertilizer. If N application was continued, rapeseed yield did not change significantly or had a downward trend. N application mainly improved rapeseed yield by increasing the number of pods per plant. N application significantly increased protein content in rapeseed. When the N application rate was 270 kg N hm^-2, the protein content was the highest. N application significantly reduced the seed oil content. For every 100 kg N hm^-2 increase in nitrogen application, the seed oil content decreased by 1.6%. With the increase of N fertilizer application rate, glucosinolate, oleic acid, linolenic acid, erucic acid, and saturated fatty acids (palmitic acid and stearic acid) increased, while linoleic acid decreased in rapeseed. Rapeseed quality decreased as a whole. In conclusion, to pursue high-quality edible oil and take into account rapeseed yield, the application rate of N fertilizer was 180 kg N hm^-2. The optimal application rate of N fertilizer was 270 kg N hm^-2 when rapeseed yield and rapeseed cake were taken into account.

Based on the two-year located straw returning experiment, to explore the effects of continuous nitrogen application on the decomposition and nutrient release of returning straw in the third year, soil fertility characteristics and maize yield in Yanghuang irrigation area of Ningxia, the effects of continual application rates of different pure nitrogen (0, 150, 300, and 450 kg hm^-2) on decomposition, nutrient release of returning straw in the third year, soil physical and chemical properties, and maize yield were studied by nylon mesh bag method and field experiment. The results showed that nitrogen application could promote straw decomposition at 50-170 DAS (days after maize sowing), and the nitrogen application rate at 300 kg hm^-2 was the best. The cumulative decomposition ratio and decomposition rate of straw under nitrogen application rate at 300 kg hm^-2 compared with that no nitrogen application treatment (the control), were significantly increased by 25.6% and 20.3%, respectively. Nitrogen application could promote the nutrient release of straw, and the cumulative nutrient release rates of returning straw was ranked: potassium > carbon > nitrogen > phosphorus. The cumulative release rate of each element in all treatments increased first and then decreased with the increase of nitrogen application rate, and the effect of nitrogen application rate at 300 kg hm^-2 was the best. Nitrogen application made the soil bulk density in 0-40 cm layer decrease, while the soil total porosity increased, and nitrogen application rate at 300-450 kg hm^-2 was the most significant. Nitrogen application could increase the soil temperature at 20 DAS and soil water storage at 80-170 DAS, and the effect of the nitrogen application rate at 300 kg hm^-2 was the best. Nitrogen application could improve soil fertility in 0-40 cm layer, and nitrogen application rate at 300 kg hm^-2 had the best effect on increasing soil organic carbon, total nitrogen, alkali-hydrolyzed nitrogen, available phosphorus, and available potassium contents. Compared with the control, nitrogen application rate at 300 kg hm^-2 could affect the yield composition and increase significantly maize yield by 63.7%. According to the comprehensive analysis, nitrogen application rate at 300 kg hm^-2 can significantly improve soil fertility characteristics, promote the decomposition and nutrient elements release of returning straw, thus contributing to the soil fertilization and the higher yield of maize in Yanghuang irrigation area of Ningxia.