Wheat (Triticum aestivum L.) yield and processing quality varied across environments, especially along altitudinal gradients. This study evaluated the combined effects of altitude above sea level and nitrogen (N) topdressing on yield and quality traits of winter wheat with strong, medium and weak gluten content. Six cultivars were tested for two growing seasons at Renqiu (4 m), Beijing (40 m) and Lhasa (3688 m). Raw-data verification showed that Lhasa reduced mean grain yield by 44.1% compared with Beijing, mainly through reductions in spike number, grains per spike and thousand-grain weight. High altitude increased total grain protein by 17.5% compared with Beijing, especially through increases in albumin and globulin fractions, but this increase did not translate into better processing quality. Strong and medium gluten wheat showed reduced gluten index, shorter dough stability time and higher weakening degree at Lhasa, whereas weak gluten wheat maintained relatively better stability under high-altitude stress. Nitrogen responses differed among gluten types: strong gluten wheat benefited more from 240 kg/ha N, medium gluten wheat performed similarly under 180-240 kg/ha N, and weak gluten wheat showed a more stable response under high-altitude conditions. Multivariate analyses separated the Lhasa environment from Renqiu and Beijing and indicated a clear yield-quality trade-off. These results suggested that cultivar selection and N management should be adjusted jointly according to altitude above sea level and gluten type.

Natural rubber (NR) is an irreplaceable material for over 40,000 products, yet 95% of global supply depends on a single tropical species, Hevea brasiliensis, creating unprecedented vulnerabilities from disease, climate change, and geopolitical instabilities. Taraxacum kok-saghyz (TKS), or Russian dandelion, represents the most promising temperate-zone alternative, containing 3-12% rubber in roots with molecular structure identical to Hevea rubber. This comprehensive review integrates TKS research spanning nine decades-from emergency wartime cultivation (1931-1950) to modern synthetic biology applications. Multi-omics approaches have collectively elucidated the TKS rubber biosynthetic pathway, encompassing the mevalonate (MVA) pathway that generates the isopentenyl pyrophosphate (IPP) monomer precursor, three core biosynthetic genes (CPT, REF, and SRPP), and the regulatory networks governing rubber accumulation. CRISPR/Cas9 genome editing achieved up to 88.9% mutation efficiency; simultaneous knockout of the two principal inulin biosynthesis genes, Tk1-SST and Tk1-FFT, redirected carbon flux from inulin toward rubber, more than doubling root rubber content. Eight cycles of recurrent selection demonstrated 84% yield improvement, though current production (32-750 kg/ha) remains below economic thresholds (1000-1500 kg/ha). Persistent agronomic challenges include poor seedling germination (field establishment rates frequently below 40% under suboptimal temperature conditions), slow firstyear vegetative growth, complex lateral root architecture that impedes mechanical harvest, and metabolic competition between rubber and inulin biosynthesis for shared carbon substrates. This review synthesizes fragmented knowledge across disciplines, identifies critical bottlenecks, and proposes integrated strategies combining genomic selection, metabolic engineering, and agronomic optimization. Successful TKS development would diversify global rubber supply chains, enhance agricultural resilience, and provide a model for rapid crop domestication using modern biotechnology.

Natural rubber (NR) is predominantly obtained from Hevea brasiliensis, where cis-prenyltransferase (CPT) catalyzes NR biosynthesis. However, the evolutionary trajectories, functional validation, and applicability of rubber tree CPTs for enhancing NR production in non-Hevea species remain unclear. Here, comparative evolutionary analysis across Euphorbiaceae family revealed that H. brasiliensis underwent a tandem duplication-driven expansion of its CPT family-especially among core members HbCPT6, HbCPT7, and HbCPT8-forming a gene cluster. Notably, HbCPT8 exhibits latex-specific expression and is significantly upregulated in secondary laticifers, linking it to NR production. In Taraxacum kok-saghyz (TKS), overexpression of HbCPT8 significantly increased rubber particles (RPs) abundance and plant biomass. Most importantly, overexpressing HbCPT8 markedly enhanced NR yield in TKS, while concurrently reducing inulin content and increasing free sugar levels. Moreover, HbCPT8 overexpression promotes the accumulation of lipids and terpenoids. Transcriptomic analysis revealed upregulation of genes involved in secondary metabolism, sesquiterpene/triterpene biosynthesis, fatty acid degradation, and carbon metabolism. Notably, key genes in mevalonate pathway and rubber elongation-including CPT/CPTL and RP-associated genes-were markedly upregulated. These findings demonstrate that HbCPT8 overexpression in TKS enhances RP biogenesis and NR biosynthesis, coordinately upregulates genes encoding core components of the rubber elongation complex and key enzymes in precursor biosynthesis, and redirects carbon flux toward isoprenoid biosynthesis, thereby increasing NR yield and terpenoid accumulation. This study confirm the evolutionarily conserved role of CPT in NR biosynthesis across rubber-producing species, establish HbCPT8 as a validated target for boosting NR production, and provide a mechanistic basis for engineering high-yielding rubber crops.

Taraxacum kok-saghyz (TKS) synthesises natural rubber (NR) and inulin using sucrose as a carbon source. However, molecular mechanisms regulating inulin and NR accumulation remain largely unclear. Here, we report the generation of double-gene homozygous mutants, 1-sst1-fft, by simultaneously knocking out two key genes responsible for inulin biosynthesis (Tk1-SST and Tk1-FFT) using CRISPR/Cas9 technology. The 1-sst1-fft mutants exhibited significant increases in rosette leaf number, flower number, leaf area, whole-plant biomass and seed set. Moreover, inulin biosynthesis was abolished in 1-sst1-fft, leading to significant changes in sugar composition, particularly a marked increase in sucrose levels. Notably, NR accumulation more than doubled, with no significant change in molecular weight and most terpenoid accumulation also increased in 1-sst1-fft, both being positively correlated with sucrose levels. For the first time, this study reports the generation of an inulin synthesis-deficient mutant in plants, emphasising the essential roles of 1-SST and 1-FFT in regulating carbon partitioning and, consequently, modulating important traits and metabolite accumulation. Transcriptomic analysis revealed fundamental genes involved in sucrose metabolism, sugar signalling and transport and NR elongation were significantly upregulated in 1-sst1-fft; accompanied by enhanced enzymatic activities of sucrose-phosphate synthase and invertase. These findings demonstrate that blocking inulin biosynthesis in 1-sst1-fft redirects sucrose towards NR biosynthesis, highlighting the dual role of sucrose as both a carbon source and signalling molecule in modulating plant growth and development and metabolite synthesis. Our study provides a successful approach to enhancing NR accumulation by modifying carbon allocation in TKS, offering novel insights into high-yield breeding strategies.

Pre-flowering total dry matter remobilization (PTDR) and post-flowering photosynthetic accumulation (PTPA) are critical for grain-filling under abiotic stress, yet their temporal dynamics and organ-specific contributions under combined high temperature (HT) and drought stress (DS) remain poorly understood. Through a two-year field study (2021–2023) with two wheat cultivars (Zhongmai36 and Jimai22), we investigated yield components, PTDR-PTPA coordination, and grain-filling dynamics under HT, DS, and combined drought-heat stress (DHS). The results demonstrated that stress treatments significantly reduced yield by 14.1–33.3

In order to study the nitrogen application rate in farmland with different fertility levels and the main destination and wheat absorption of N-fertilizer, to improve nitrogen use efficiency, three soils with different fertility levels were selected: chernozems soils (CS)、fluvo-aquic soils (FS) and rougi-limestone soils (RS), were used to study the effects of soil and nitrogen application rate on nitrogen fate of “wheat-soil” under the same ecological environment by isotope tracer technique in this experiment. The results showed that grain yield and nitrogen absorption of wheat in CS which with high fertility and nutrient content were significantly higher than that in FS and RS. Nitrogen fertilizer has a greater impact on the nitrogen content of FS and RS than on black soil. The ability of wheat to utilize residual fertilizer nitrogen in soil is less affected by the amount of nitrogen applied in the last season and is more affected by soil conditions, as CS > FS > RS. After planting two-season wheat, the proportion of nitrogen recovered by the wheat-soil is 37–68%, of which the nitrogen fixed by the soil accounts for 13–32% of the applied nitrogen. The average nitrogen loss of CS is 77.4 kg N·ha− 1, that of FS is 102.9 kg N·ha− 1 and that of RS is 153.1 kg N·ha− 1, indicating that the CS condition is conducive to the absorption of N-fertilizer by wheat, with the least nitrogen loss and the least impact on the environment. When nitrogen application rate from 120 kg·ha− 1 increased to 360 kg·ha− 1, the nitrogen loss rate increased by 6.58 percentage points, but the nitrogen loss increased from 51.5 kg·ha− 1 to 178.2 kg·ha− 1, and the impact on the environment increased significantly. Therefore, we should pay attention to improve soil fertility and structure, and select the appropriate amount of nitrogen according to the actual situation of soil, so as to realize the synergistic improvement of wheat yield and nitrogen utilization, reduce resource consumption and the impact of nitrogen fertilizer on the environment in wheat production.

MADS-box transcription regulators play important roles in plant growth and development. However, very few MADS-box genes have been isolated in the genus Taraxacum, which consists of more than 3000 species. To explore their functions in the promising natural rubber (NR)-producing plant Taraxacum kok-saghyz (TKS), MADS-box genes were identified in the genome of TKS and the related species Taraxacum mongolicum (TM; non-NR-producing) via genome-wide screening. In total, 66 TkMADSs and 59 TmMADSs were identified in the TKS and TM genomes, respectively. From diploid TKS to triploid TM, the total number of MADS-box genes did not increase, but expansion occurred in specific subfamilies. Between the two genomes, a total of 11 duplications, which promoted the expansion of MADS-box genes, were identified in the two species. TkMADS and TmMADS were highly conserved, and showed good collinearity. Furthermore, most TkMADS genes exhibiting tissue-specific expression patterns, especially genes associated with the ABCDE model, were preferentially expressed in the flowers, suggesting their conserved and dominant functions in flower development in TKS. Moreover, by comparing the transcriptomes of different TKS lines, we identified 25 TkMADSs related to biomass formation and 4 TkMADSs related to NR content, which represented new targets for improving the NR yield of TKS.

In order to study the nitrogen regulating effects on yield and agronomic traits of different gluten wheat cultivars, three topdressing nitrogen amounts of 75, 105, and 135kg/ha were set in Beijing experimental base of Institute of Crop Sciences, Chinese Academy of Agricultural Sciences during 2016-2017. The tested materials were strong gluten（Gaoyou 2018 and Shiluan 02-1）, medium gluten（Zhongmai 8 and Zhongmai 175）and weak gluten（Yangmai 22 and Yangmai 15） cultivars. Nitrogen fertilizer 105kg/ha and phosphorus fertilizer（135kg/ha） were applied as base fertilizers. The results showed that increasing the amount of topdressing nitrogen could promote polarization at jointing stage, reduce ineffective tillering, and increase the number of spikes, and the effects on strong gluten cultivars was greater than that of medium and weak gluten cultivars.Increasing the amount of topdressing nitrogen in the range of 75-135kg/ha could improve the leaf area indexes of all cultivars, slow down the decline rate of leaf area index from flowering to grain filling stage, and the effects on medium gluten cultivars was the most obvious. The plant height, spike length and the number of bearing spikelets were the highest under nitrogen topdressing at 135kg/ha, while the number of sterile spikelets decreased significantly with the increase of nitrogen application. In the range of 75-135kg/ha, the grain yield, the number of spikes, grains per spike and 1000-grain weight of each gluten-type cultivar increased significantly with the increase of topdressing nitrogen, and 135kg/ha treatment was the highest.

To explore the impacts of global climate change on the suitable sowing date for winter wheat in north winter wheat area of China, we carried out a wheat sowing date experiment during growing seasons of 2019-2021 at the Beijing Experimental Base of the Institute of Crop Sciences, CAAS. Two winter wheat cultivars with different tillering powers were selected as experimental materials. Four different sowing dates were set: September 25th (J), October 5th (S0), October 15th (S1) and October 25th (S2), to examine the responses of population quality, individual characters, and stem and tiller physiology to the accumulated temperature difference before overwintering. The results showed that with the delay of sowing date, the accumulated temperature before winter and their difference between the adjacent sowing dates decreased gradually. The accumulative temperature at the sowing J and S0 both exceeded 550 ℃, which met the basic condition for the formation of strong wheat seedlings before winter. The average accumulated temperature at sowing S1 and S2 was 148.0 and 282.4 ℃ lower than that of S0, which was not conducive to the establishment of strong wheat seedlings before winter. The average accumulated temperature decreased by 204.0, 148.0 and 134.4 ℃, when the sowing date was delayed by 10 days under the four different sowing dates, respectively. The days from sowing to emergence were affected by the average daily temperature. The days from sowing to emergence gradually increased with the delay of sowing date when the daily average temperature was lower than 15 ℃, while the days from sowing to emergence were constant when the daily average temperature was higher than 15 ℃. The total stem number, leaf area index, dry matter weight, nitrogen accumulation and tiller number per plant of wheat also decreased with the decreases of pre-winter accumulated temperature. The soluble sugar content and nitrate reductase activity at the seedling increased first and then decreased with the decreases of accumulated temperature before winter, while the soluble protein content and glutamine synthetase activity to accumulated temperature performed differently among varieties. According to the population quality and individual traits of wheat before winter, among the four different sowing dates, the total stem number and tiller number per plant of wheat before sowing on October 5 were the closest to the standard of strong seedlings before winter in north winter wheat area. The accumulated temperature before winter is conducive to the formation of strong seedlings. When the daily average temperature is 15-17 ℃, it is the best sowing time for winter wheat in Beijing.

Water is the key factor limiting the improvement of wheat yield and quality. In order to explore the effects of irrigation in different periods on winter wheat yield, agronomic characteristics, grain quality and photosynthetic performance, four water treatments were set under conditions of automatic rain-proof shelter that water and fertilizer were controlled: no watering（control treatment, W1）, water 1050m~3/ha at jointing stage（W2）, water 1050m~3/ha at flowering stage（W3）, and water 525m~3/ha at jointing stage + 525m~3/ha at flowering stage（W4）. The results showed that, the grain protein content of W1 treatment, the protein yield of W2 treatment and the grain yield of W3 treatment were the highest. W4 treatment had the most stable photosynthetic performance. Compared with W1 treatment, irrigation affected the photosynthetic performance of wheat flag leaves, increased its net photosynthetic rate, stomatal conductance, intercellular CO 2 concentration and transpiration rate. Irrigation at jointing stage increased leaf chlorophyll content, dry matter accumulation and grain protein yield, and increased biological yield by increasing the number of spikes and grains per spike. Irrigation at flowering stage could increase grain length and width, increase sink capacity, and increase grain yield by increasing weight. By comparing W1, W4 and W2 treatments after irrigation at jointing stage and before irrigation at flowering stage, it was found that irrigation increased the maximum net photosynthetic rate and light saturation point, decreased the dark respiration rate, and the flag leaf was more adapted to strong light, but could not further increase the photosynthetic efficiency, and the weakening range of flag leaf adaptation to strong light increased with time. With the same amount of irrigation, irrigation only once at flowering stage or twice at jointing stage and flowering stage could prevent the decline of photosynthetic performance and the earlysenescence of leaves at the later stage. Therefore, attention should be paid to the role of water in different growth periods in production, and irrigation should be carried out in time according to the actual precipitation and production demand.

Background Taraxacum kok-saghyz Rodin (TKS) is a promising commercial alternative natural rubber (NR) yielding plant. Cultivating TKS with a high NR content is an important breeding target, and developing molecular markers related to NR content can effectively accelerate the breeding process of TKS. Results To construct a high-density SNP genetic map and uncover genomic regions related to the NR content in TKS, an F 1 mapping population of TKS was constructed by crossing two parents (l66 and X51) with significant differences in NR contents. The NR content of the F 1 plants ranged from 0.30 to 15.14% and was distributed normally with a coefficient of variation of 47.61%, indicating quantitative trait inheritance. Then, employing whole-genome resequencing (WGR), a TKS genetic linkage map of 12,680 bin markers comprising 322,439 SNPs was generated. Based on the genetic map and NR content of the F 1 population, six quantitative trait loci (QTLs) for NR content with LOD > 4.0 were identified on LG01/Chr01 and LG06/Chr06. Of them, the 2.17 Mb genomic region between qHRC-C6-1 and qHRC-C6-2 on ChrA06, with 65.62% PVE in total, was the major QTL region. In addition, the six QTLs have significant additive genetic effects on NR content and could be used to develop markers for marker-assisted selection (MAS) in TKS with a high NR content. Conclusion This work constructed the first high-density TKS genetic map and identified the QTLs and genomic regions controlling the NR content, which provides useful information for fine mapping, map-based cloning, and MAS in TKS.

The study of the effects of different sowing methods on the yield and quality of different varieties provides an effective reference for high-yield and high-efficiency wheat cultivation measures. This experiment used a two-factor randomized block design. The sowing methods were uniform sowing（A1） and conventional drill seeding（A2）. The wheat varieties were Hengguan 35（B1）, Han 6172（B2）, Lunxuan 103（B3） and Shimai25（B4）. The results showed that, the two sowing methods had significant differences in influence on plant traits.The plant height and number of grains per spike of drill sowing were significantly higher than that of uniform sowing. The yield, spike number and 1000-grain weight of uniform sowing were significantly higher than those of drill sowing, and the yield of uniform sowing treatment was 4.42% higher than that of drill sowing treatment.The sowing method had a significant effects on the bulk weight, hardness index, yield rate and 14% water absorption. The bulk weight of wheat under uniform sowing was 2.02 percentage points higher than that of drill sowing. Shimai 25 had the highest yield and Hengguan 35 had better flour quality. The yields of Hengguan 35,Han 6172 and Lunxuan 103 under uniform sowing were higher, and the farinogram quality index of Han 6172was better.

In Beijing experiment base of Institute of Crop Sciences,Chinese Academy of Agricultural Sciences a two-factor randomized block design was conducted to explore the effects of nitrogen application on the yield and quality of weak-gluten wheat in northern winter wheat regions during 2016-2017.The factor A was weak gluten wheat cultivar （Yangmai 22 and Yangmai 15） and the factor B was nitrogen rate （N 180,210 and240kg/ha）.The results showed that within the nitrogen range of 180-240kg/ha,grain yield,ear number per uni area,grain number per ear,1000-grain weight,protein yield and biological yield all increased with the increase of nitrogen application rate.With the increase of nitrogen application rate,the total protein and contents of its components showed an increasing trend,and the increase of gliadin and glutenin was higher than that of albumin and globulin.Compared with treatment of 180kg/ha,the ratio of gluten to alcohol under 210 and 240kg/ha treatments decreased by 0.27 and 0.41 percentage points,respectively;bulk density,hardness,and flour extraction rate were expressed as Yangmai 22＞Yangmai 15.Sedimentation,wet gluten,water absorption,dough formation time,stable time,and farinograph quality value of the two quality types of wheat all increased with the increase of nitrogen application rate with the average increase rates of 5.53%,2.54%,0.54%,17.82%,7.07%and14.17%,respectively.The degree of weakening decreased with the increase of nitrogen application rate,and the two varieties decreased by 9.65%and 12.00%,respectively.Therefore,comprehensively considering fertilizer input,wheat yield and quality indicators,applying N 180kg/ha to weak gluten wheat in the northern winter whea regions could obtain higher yield and processing quality.

APC/C是一类泛素连接酶E3复合体,在调控细胞周期过程中发挥重要作用.为了揭示橡胶草APC/C蛋白复合体的功能,鉴定了橡胶草TkAPC10基因,并对其表达模式进行了分析,初步确定了其功能.TkAPC10基因的ORF为579 bp,编码192个氨基酸,其基因组DNA序列为1092 bp,包含6个外显子和5个内含子.基因组分析发现,TkAPC10以单拷贝的形式存在,其启动子序列除了含有TATA-box和CAAT-box增强子元件外,还有ABA、JA、光以及逆境响应相关的顺式作用元件.系统进化关系分析发现,不同物种的APC10蛋白具有很高的同源性,TKAPC10与莴苣LsAPC10的相似性最高达到99％,而与其他菊科植物的APC10蛋白相似性也达到95％以上.进一步采用qRT-PCR技术对TKAPC10的表达模式进行分析,结果表明,该基因在细胞分裂旺盛的组织(花、叶和根)中的表达量显著高于细胞分裂活动相对缓慢的组织(花梗).外源ABA处理后,TKAPC10基因转录水平显著下降;而MeJA和ET处理后,该基因显著上调表达.经PEG6000以及甘露醇处理后,TKAPC10表达水平显著下降;而高盐胁迫显著诱导该基因的表达.TKAPC10基因参与橡胶草细胞分裂、激素信号以及非生物胁迫响应过程的调控.

[目的]研究不同筋型小麦干物质和氮素积累对追施氮量的响应,揭示其干物质积累特征,为资源高效利用提供科学参考.[方法]田间试验于2016—2017年在中国农业科学院作物科学研究所北京试验基地进行,供试品种为强筋小麦'藁优2018'和'师栾02-1',中筋小麦'中麦8号'和'中麦175',弱筋小麦'扬麦22'和'扬麦15'.在基施纯氮105 kg/hm2的基础上,设N 75、105和135 kg/hm23个追氮量处理,于拔节期追施.调查分析了小麦花前、花后干物质和氮素的积累与分配,产量及其构成因素.[结果]随着追氮量增加,开花期各筋型小麦干物质积累量均呈增加趋势,但各器官干物质分配比例的变化在不同筋型小麦间不完全相同,其中强筋小麦叶片占比升高,穗占比降低;中筋和弱筋小麦茎秆占比升高,叶片占比降低,穗则先升后降.提高追氮量对成熟期小麦干物质积累的影响主要表现为显著提高了颖壳+穗轴的比例,其他器官占比变化较小,但各器官干物质积累量总体呈增加趋势.随追氮量增加,成熟期各类型小麦营养器官和籽粒氮素积累量、营养器官氮素向籽粒中的转移量呈增加趋势,中筋小麦营养器官花前氮素转运率及贡献率显著降低,强筋和弱筋小麦营养器官花前氮素贡献率逐渐提高;中筋小麦花后氮素转运量显著提高,弱筋小麦花后氮素贡献率则显著降低.增加追氮量可显著提高弱筋小麦穗数、强筋小麦穗粒数、强筋和中筋小麦千粒重;不同筋型小麦产量虽有提高,但差异不显著.[结论]在本试验条件下,强筋小麦干物质积累与分配、氮素积累与转运以追施N 105 kg/hm2为宜,可以保证较高的穗粒数和千粒重,稳定产量.中筋小麦在追施N 135 kg/hm2时,可以显著提高干物质积累、氮素吸收转运及千粒重,保证较高产量.弱筋小麦在追施N 135 kg/hm2时,可以促进植株干物质积累、花前氮素积累与转运,提高对籽粒氮素的贡献率,通过提高成穗数实现产量提升.

2020/2021年度在黄淮冬麦区南片的4个省份分别设置大田试验,选择周麦18、周麦36及爱民蓝麦1号3个不同品质类型的冬小麦品种,分析比较不同气象因子对3个品种小麦产量及品质的影响.结果表明:不同小麦品种特性和试验点生态环境对小麦籽粒长宽、产量及品质的影响均达到显著水平,其中籽粒长度、株高及产量受环境条件的影响大于品种基因型,而籽粒宽度、产量三要素、籽粒淀粉、蛋白质和纤维素含量受品种基因型的影响大于环境条件.从不同试验点气象因子来看,籽粒长宽和千粒重表现一致,主要受抽穗?灌浆中期水分的正向调控和拔节?成熟期气温的负向调控;株高主要受拔节期水分和气温的正向调控;产量和穗粒数主要受抽穗期水分和气温、灌浆中期水分的正向调控;有效穗数主要受拔节?抽穗期日照时数的正向调控.籽粒淀粉含量受拔节后气温、水分的正向调控,受扬花后期日照时数的负向调控,籽粒蛋白质含量则与其相反,纤维素主要受抽穗?灌浆中期水分的正向调控.综上所述,不同小麦品种特性和试验点生态环境对小麦籽粒长宽、产量及品质均存在显著影响;拔节后的平均气温、总供水量及总日照时数对小麦籽粒表型、产量及品质性状的影响存在差异.

为了解小麦产量和品质对不同类型土壤和施氮处理的响应,以津强11号为试验材料,研究不同类型土壤(黑土、潮土)和施氮处理(不施肥、底施、三叶期施、拔节期施、抽穗期施)对春小麦产量和品质的调控效应.结果表明,土壤养分含量较高的黑土更有利于小麦穗部性状及产量和品质的提高,黑土处理小麦的总小穗数、穗粒数、千粒重、籽粒产量较潮土分别提高5.76％、28.07％、18.37％和38.4％,蛋白质含量及其产量提高14.35％和38.37％,差异均极显著(P＜0.01).不同施氮处理间比较,穗部性状与籽粒产量均以拔节期施氮最高;各施氮处理较不施氮处理籽粒谷蛋白含量均大幅度提高,以抽穗期施氮的籽粒蛋白质含量最高.黑土和潮土中,在拔节期或抽穗期追肥均可以有效提高小麦籽粒产量和品质.籽粒圆度表现为潮土＞黑土,其他籽粒性状在各处理间均无显著差异.

Wheat flour products are the main dietary component of the Qinghai-Tibetan Plateau (QTP) population in China. However, the high altitude restricts the local wheat quality and quantity, and the applied nitrogen rate is higher than the optimal rate for wheat planting. In this study, we considered whether reducing the amount of nitrogen fertilizer and introducing the superior varieties from the North China Plain (NCP) are viable ways to increase the wheat quality and quantity in the QTP. Three and four winter wheat cultivars from QTP and NCP, respectively, were planted in Lhasa at an altitude of 3 647 m with reduced topdressing nitrogen application at the jointing stage. The wheat from NCP exhibited higher grain hardness index and test weight, and better flour and dough quality. Reducing the topdressing nitrogen fertilizer from 135 to 75 kg N ha(-1) at the jointing stage (with the same basal fertilization of 105 kg N ha(-1)) did not significantly (P<0.05) affect the grain yield, grain quality, flour quality or dough quality in any of the cultivars. In summary, introducing high-quality winter wheat varieties from the NCP to the Lhasa plateau is a viable way to enhance the wheat supply and quality in the QTP. Reducing a certain amount of the nitrogen fertilizer is an economic and feasible approach for the QTP region.

为解决我国北部冬麦区因播期推迟造成越冬前小麦苗情较弱的实际问题,于2019—2021年在中国农业科学院北京试验基地进行晚播试验,设3个播期:10月5日适期播种(S0)、10月15日适当晚播(S1)、10月25日过晚播(S2),以S0为对照,对晚播S1、S2采取覆膜和补施氮肥的调控措施,研究覆膜和补施氮肥对晚播小麦冬前群体质量、个体性状以及茎蘖生长的影响.结果表明:晚播不利于小麦冬前群体和个体质量的形成,以及茎蘖的生长.晚播覆膜增温可提高冬前群体总茎数,与不覆膜处理相比,适当晚播和过晚播覆膜处理提高了小麦冬前群体生长率和相对生长率,群体总茎数平均分别提高42.9％、148.4％;植株冬前叶龄增加,个体分蘖数平均分别增加1.6个和2.0个;覆膜增温延长主茎上第1分蘖至第3分蘖营养生长进程,提高苗期茎叶、分蘖节、根部可溶性糖含量以及叶片中生长素与玉米素核苷的比值(IAA/ZR),增加冬前群体总茎数.对各处理进行晚播苗情评价可得出,适期播种条件下均有利于2个不同分蘖力品种冬前群体综合质量的提高,其中,多穗型品种中麦8号在晚播覆膜条件下其晚播苗情较好,大穗型品种航麦501则在适当晚播无调控措施、适当晚播+补施氮肥、适当晚播+覆膜和过晚播+覆膜条件下其晚播苗情较好,同时2个不同分蘖力品种在晚播条件下对覆膜增温的响应存在差异.中麦8号在适期播种或晚播覆膜条件下更有利其冬前群体综合质量的提升,而航麦501在适期播种、适当晚播和过晚播覆膜条件下均有利于其晚播苗期质量的提高.补施氮肥则对晚播小麦冬前群体质量、个体性状和茎蘖生长无明显调控效应.综上所述,在晚播条件下,覆膜可有效改善小麦冬前群体和个体的综合质量,进一步促进茎蘖的生长.