Nitrogen management improves lodging resistance and production in maize(Zea mays L.)at a high plant density

Lodging in maize leads to yield losses worldwide.In this study,we determined the effects of traditional and optimized nitrogen management strategies on culm morphological characteristics,culm mechanical strength,lignin content,root growth,lodging percentage and production in maize at a high plant density.We compared a traditional nitrogen(N)application rate of 300 kg ha–1(R)and an optimized N application rate of 225 kg ha^(–1)(O)under four N application modes:50%of N applied at sowing and 50%at the 10th-leaf stage(N1);100%of N applied at sowing(N2);40%of N applied at sowing,40%at the 10th-leaf stage and 20%at tasseling stage(N3);and 30%of N applied at sowing,30%at the 10th-leaf stage,20%at the tasseling stage,and 20%at the silking stage(N4).The optimized N rate(225 kg ha^(–1))significantly reduced internode lengths,plant height,ear height,center of gravity height and lodging percentage.The optimized N rate significantly increased internode diameters,filling degrees,culm mechanical strength,root growth and lignin content.The application of N in four split doses(N4)significantly improved culm morphological characteristics,culm mechanical strength,lignin content,and root growth,while it reduced internode lengths,plant height,ear height,center of gravity height and lodging percentage.Internode diameters,filling degrees,culm mechanical strength,lignin content,number and diameter of brace roots,root volume,root dry weight,bleeding safe and grain yield were significantly negatively correlated with plant height,ear height,center of gravity height,internode lengths and lodging percentage.In conclusion,treatment ON4 significantly reduced the lodging percentage by improving the culm morphological characteristics,culm mechanical strength,lignin content,and root growth,so it improved the production of the maize crop at a high plant density.

Rapid and efficient method for isolating plant high molecular weight(HMW)DNA with high purity

PREPARATION of HMW DNA (Megabase-size) is the basis for construction of genomic library with large DNA inserts such as bacterial artificial chromosome (BAC) and yeast artificial chromosome (YAC), and for long-range physical mapping. It can also be used for the macro-study of repeat sequences. Since HMW DNA during preparation is inclined to be sheared physically and digested by internal nucleases, it is very difficult to prepare the HMW DNA. Initially, plant HMW DNA was prepared by embedding protoplasts in the low melting-point (LMP) agarose; however, it had several disadvantages: (ⅰ) Culture of protoplasts was time-consuming, costly and tedious. ( ⅱ ) It was only used successfully for limited

High Plant Species Distributed in and around Dengizkul, Bukhara Region

The article presents the results of research conducted in Dengizkul and around this area. It identifies plant species in and around the lake and analyzes species composition. As a result of the analysis, 70 species of tall plants belonging to 24 families were identified in the lake. The identified species are divided into aquatic and riparian plants. Of these, 18 species are found in lake water and 52 species in its vicinity. The low number of high plant species in the lake water is due to the salinity of the water. The protection of this area is based on the natural conservation of the surrounding plant population.

Rapid and Reliable Method of High-Quality RNA Extraction from Diverse Plants

The isolation of high quality RNA is a crucial technique in plant molecular biology. The quality of RNA determines the reliability of downstream process like real time PCR. In this paper, we reported a high quality RNA extraction protocol for a variety of plant species. Our protocol is time effective than traditional RNA extraction methods. The method takes only an hour to complete the procedure. Spectral measurement and electrophoresis were used to demonstrate RNA quality and quantity. The extracted RNA was further used for cDNA synthesis, expression analysis and copy number determination through Real Time PCR. The results indicate that RNA was of good quality and fit for real time PCR. This high throughput plant RNA extraction protocol can be used to isolate high quality RNA from diverse plants for real time PCR and other downstream applications.

Highly efficient CRISPR-SaKKH tools for plant multiplex cytosine base editing

Base editing, as an expanded clustered regularly interspaced short palindromic repeats(CRISPR)-Cas genome editing strategy, permits precise and irreversible nucleotide conversion. SaKKH, an efficient variant of a Cas9 ortholog from Staphylococcus aureus(SaCas9), is important in genome editing because it can edit sites with HHHAAT protospacer adjacent motif(PAM) that the canonical Streptococcus pyogenes Cas9(SpCas9) or its variants(e.g. xCas9, Cas9-NG) cannot. However, several technical parameters of SaKKH involved base editors have not been well defined and this uncertainty limits their application. We developed an effective multiplex cytosine base editor(SaKKHn-pBE) and showed that it recognized NNARRT, NNCRRT, NNGRGT, and NNTRGT PAMs. Based on 27 targets tested, we defined technical parameters of SaKKHn-pBE including the editing window, the preferred sequence context, and the mutation type. The editing efficiency was further improved by modification of the SaKKH sgRNA. These advances can be applied in future research and molecular breeding in rice and other plants.

High Temperature as a Mechanism for Plant Cytoplasm Preservation in Fossils

Because the cytoplasm of a plant normally degrades after the death of the plant, finding cytoplasm in a plant body after a prolonged period of time, especially in fossil plants, is unexpected. Recent work on several 100-Myr-old plant fossils from Kansas, USA indicates, however, that cells and their contents can be preserved. Most of the cells in these fossil plants appear to be in a state of plasmolysis, and these fossil cells bear a strong resemblance to laboratory-baked cells of extant plant tissues. Based on a comparison with extant material plus biophysical and biochemical analyses of the cytoplasm degrading process, a new hypothesis for cytoplasm preservation in nature is proposed： high temperature, a concomitant of commonly seen wildfires, may preserve cytoplasm in fossil plants. This hypothesis implies that fossilized cytoplasm should be rather common and an appropriate substance for research, unlike previously thought. Research on fossil cytoplasm closely integrates paleobotany with biochemistry, biophysics, as well as fire ecology, and invites inputs from these fields to paleobotany to interpret these provocative findings.

Genome-wide association study and metabolic pathway prediction of barrenness in maize as a response to high planting density

Increasing the planting density is one way to enhance grain production in maize.However,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain yield.In this study,the barrenness was characterized in an association panel comprising 280 inbred lines under normal(67500 plants ha–1,ND)and high(120000 plants ha–1,HD)planting densities in 2017 and 2018.The population was genotyped using 776254 single nucleotide polymorphism(SNP)markers with criteria of minor allele frequency>5%and<20%missing data.A genome-wide association study(GWAS)was conducted for barrenness under ND and HD,as well as the barrenness ratio(HD/ND),by applying a Mixed Linear Model that controls both population structure and relative kinship(Q+K).In total,20 SNPs located in nine genes were significantly(P<6.44×10–8)associated with barrenness under the different planting densities.Among them,seven SNPs for barrenness at ND and HD were located in two genes,four of which were common under both ND and HD.In addition,13 SNPs for the barrenness ratio were located in seven genes.A complementary pathway analysis indicated that the metabolic pathways of amino acids,such as glutamate and arginine,and the mitogen-activated protein kinase(MAPK)signaling pathway might play important roles in tolerance to high planting density.These results provide insights into the genetic basis of high planting density tolerance and will facilitate high yield maize breeding.

Evidence of arrested silk growth in maize at high planting density using phenotypic and transcriptional analyses

Increasing the planting density is an effective way to increase the yield of maize(Zea mays L.),although it can also aggravate ovary apical abortion-induced bald tips of the ears,which might,in turn,reduce the yield.While the mechanism underlying the regulation of drought-related abortion in maize is well established,high planting density-related abortion in maize remains poorly understood.Therefore,the present study was designed to investigate the mechanism underlying the ovary apical abortion response to high density.This was achieved by evaluating the effects of four different plant densities(60000 plants ha^(–1)(60 k),90 k,120 k,and 150 k)on plant traits related to plant architecture,the plant ear,flowering time,and silk development in two inbred lines(Zheng58 and PH4CV)and two hybrid lines(Zhengdan958 and Xianyu335).The phenotypes of both inbred and hybrid plants were observed under different planting density treatments,and the high planting density was found to increase the phenotypic performance values of the evaluated traits.The anthesis–silking interval(ASI)was extended,and the amount of the silk extruded from husks was reduced upon increasing the planting density.Delayed silk emergence resulted in asynchronous flowering and ear bald tips.Observations of the silk cells revealed that the silk cells became smaller as planting density increased.The changes in transcript abundances in the silks involved the genes associated with expansive growth rather than carbon metabolism.These findings further our understanding of silk growth regulation under high planting density and provide a theoretical basis for further research on improving high planting density breeding in maize.

Study on Plant Morphological Traits and Production Characteristics of Super High-Yielding Soybean

Super high-yielding soybean cultivar Liaodou 14, soybean cultivars from Ohio in the United States, and the common soybean cultivars from Liaoning Province, China, with similar geographic latitudes and identical pod-bearing habits were used as the study materials for a comparison of morphological traits and production characteristics to provide a theoretical basis for the breeding of improved super high-yielding soybean cultivars. Using a randomized block design, different soybean cultivars from the same latitude were compared under conventional and unconventional treatments for their production characteristics, including morphological traits, leaf area index （LAI）, net photosynthesis rate, and dry matter accumulation. The specific characteristics of the super high-yielding soybean cultivar Liaodou 14 were analyzed. The results showed that the plant height of Liaodou 14 was significantly lower than that of the common cultivars from Liaoning, whereas the number of its main-stem nodes was higher than that of the cultivars from Ohio or Liaoning. A high pod density was observed in Liaodou 14 under conventional treatments. Under both conventional and unconventional treatments, the branch number of Liaodou 14 was markedly higher than that of the common cultivars from Liaoning, and its branch length and leaf inclination angle were significantly higher than those of common cultivars from Liaoning or Ohio. Only small changes in the leaf inclination angle were observed in Liaodou 14 treated with conventional or unconventional methods. Under each treatment, Liaodou 14 exhibited the lowest amplitude of reduction in SPAD values and net photosynthesis rates from the grain-filling to ripening stages; the cultivars from Ohio and the common cultivars from Liaoning exhibited more significant reductions. Liaodou 14 reached its peak LAI later than the other cultivars but maintained its LAI at a higher level for a longer duration. Under both conventional and unconventional treatments, Liaodou 14 produced a higher yield than the other two cultivars, with significant differences from the Ohio cultivars. In summary, super high-yielding soybean cultivars have several main features： suitable plant height, high pod density, good leaf structure with strong functionality, and slow leaf senescence at the late reproductive stage, which is conducive to the accumulation of dry matter and improved yield.

Nutritive Equilibrium in Rice Plant Populations for High Yield

The effects of nitrogen, phosphorus and potassium application level, seed rate and transplanting density on the growth and development of rice plants were studied to find out nutrient status in high-yielding rice plants and to increase grain yield by adequate fertilization. There was an equilibrium relationship among nutrient elements for high-yielding rice plant populations. The equilibrium index of nutrient amount, content and distribution in high-yielding rice plants should be generally greater than-2 but less than 2. The optimum nutritive proportion of nitrogen: phosphorus: potassium assimilated by the plants was about 10: 2: 9 at the ripening stage. But the content and the proportion varied with the growth stages. Therefore, the nutrient in rice plant populations should be in a dynamic equilibrium, so as to achieve high yield.

Distribution of High Water Plants of Lake Karakir in Bukhara Region in Ecological Groups

In this article, information about the geographical location of the Karakir Lake in Bukhara region, high water plants, systematics and their distribution is presented. As a result of the research, Lake Karakir has 34 species of high water plants belonging to 16 families. These plants were divided into ecological groups and analyzed.

Growth and Yield of Guar (Cyamopsis tetragonoloba L.) Genotypes under Different Planting Dates in the Semi-Arid Southern High Plains

Guar is a drought and salt tolerant summer annual legume, which could be a potential alternative crop in the semi-arid Southern High Plains. Increased use of guar gum in oil industries has increased the demand of guar globally. Planting date effects on stand establishment, physiological parameters, and yield formation of guar genotypes were investigated at the New Mexico State University’s Agricultural Science Center at Clovis, NM for two seasons (2014 and 2015). Four guar genotypes (HES 1123, Kinman, Lewis, and Matador) were tested under three planting dates (June 18, July 7, and July 22 in 2014;and June 18, July 6, and July 20 in 2015). Higher temperature and rainfall were recorded under mid-June planting than early-July and late-July plantings. Guar planted under mid-June had better stand establishment as shown by the higher number of plants m-2, better physiology as revealed by higher photosynthetic rate (Pn), transpiration rate (Tr), leaf area index (LAI), and SPAD values than early-July and late-July plantings. Guar planted under mid-June resulted in taller plants, and therefore, produced higher plant biomass than both of the July plantings. Yield attributing characteristics including clusters plant-1, pods plant-1, seeds plant-1, seed spod-1, 1000 seed weight, and harvest index (HI) were highest under mid-June planting followed by the early-July and late-July plantings, respectively. The mid-June planting increased seed yield by 26% and 55% over early-July and late-July (1399 vs. 1111 and 903 kg·ha-1) plantings, respectively in 2014;while the same increase in 2015 was 51% and 243% (1308 vs. 868 and 381 kg·ha-1), respectively. These results indicate that delaying planting beyond mid-June is detrimental to guar productivity. However, genotypes did not show any significant variation in their performance. Overall, warmer growing conditions and more precipitation under mid-June planting caused better growth and yield formation of guar genotypes.

Ex-Situ Cultivation of Medicinal Plant Species in High Altitudes at Swat,Pakistan

An ex-situ experiment was conducted to evaluate the growth performance of six medicinal species (Bergenia ciliata,Valeriana jatamansi,Dioscorea deltoidea,Paeonia emodi,Polygonum amplexicaule and Viola serpense) from upper Swat,Pakistan.Experiments were conducted at four different locations in the upper Swat valley at altitudes ranging from 1200 to 1900 m.a.s.l.The objectives were:1) to determine the suitability of ex-situ cultivation of different medicinal species,and;2) to assess the economic geasibility of growing medicinal plants in the area.A highest mean survival of 80.7% across all locations was observed for Viola serpense,followed by 58.7% for Valeriana jatamansi.The remaining four species exhibited very poor survival rates,although Polygonum amplexicaule,did show encouraging signs of growth and flowered,before experiencing high mortality rates late in the trial.Altitude generally seemed to enhance the degree of sprouting for all species except Viola serpense.However,the productive yield of V.serpense was certainly not reduced,but rather slightly enhanced in the higher altitude sites.Overall,cultivation of only two of the investigated species,Valeriana jatamansi and Viola serpense,appeared successful and potentially economically viable under farmland conditions at upper Swat.

Evaluation on nitrogen isotopes analysis in high-C/N-ratio plants using elemental analyzer/isotope ratio mass spectrometry

Elemental analyzer/isotope ratio mass spectrometry(EA/TRMS) has been widely applied to analyze the^(15)N/^(14)N isotope composition(δ^(15)N) of plants and soils,but the δ^(15)N results may be inaccurate due to incomplete combustion of the high-C/N-ratio plant samples by EA.Therefore,it is necessary to develop a method to solve the problem of imperfect combustion.In this study,we used two methods:1) adding copper oxide powder to the samples,and 2) increasing the O_2 flow(from 100 mL min^(-1) to 200 mL min^(-1)) for the auto sampler inlet purge line of the EA.The δ^(15)N values of the plant samples became more positive and tended to be stable after complete combustion.Also,the required blank samples for each plant sample decreased with increasing amount of the added CuO powder.However,at 200 mL min^(-1) of the oxygen flow in the EA,complete combustion could not be achieved without adding copper oxide,but this was done with decreased amount of CuO powder.Therefore,mixing cupric oxide into the high-C/N-ratio samples was an efficient,simple and convenient way to solve the problem of imperfect combustion in the EA.

The Experiment Study of the Influence on Plant Seeds and Aquatic Biological Survival in High Altitude Environment

There is A certain foundation in this experiment. It was the second time we did this experiment. The purposes are three parts, first, explore the 30000~40000 meters high sky with two cameras recording the scene. The Second, find out whether the high sky condition(temperature, air pressure, cosmic ray) make influence on plants seeds. The third, text whether normal aquatic animal is able to survive in high sky. The conclusions are also three parts. It is important to set a deadline for my group member to finish the assignment, and also check their process, or they might delay their own part of work or they are not in charge of the work. As the leader, I should be thoughtful. Not only about members’ assignment, but also the details of their work, previously. Discuss about each task with group to ensure the correctness. Last but not least, every part of the experiment needs to be tested carefully. Only if we try our best to prevent accidents that might happen, then the experiment is able to success.

新阶段植物营养学的研究重点

植物营养学是研究营养元素在土壤-植物系统迁移、转化和利用规律的基础性学科,是支撑全球粮食安全、耕地质量安全、生态环境安全的重要学科。以组学技术和人工智能为代表的学科前沿不断拓展了植物营养学的研究范畴,同时,耕地高强度利用下如何实现作物高产、养分高效、生态健康等多重目标成为新阶段植物营养学的研究重点和难点。本文回顾了近年来植物营养学在营养遗传、养分循环、新型肥料、高效施肥等方向取得的创新进展,同时,基于我国植物营养学研究短板,提出了新阶段植物营养学研究的重点任务,主要包括作物养分高效与抗逆分子调控网络、土壤养分循环与微生物组功能挖掘、新型绿色高效肥料创制与应用、农田养分协同优化原理与方法等方面,旨在推动农业高质量发展,为保障粮食安全和农业绿色发展提供科技支撑。

间作黄芪对当归根际土壤微生物的影响

目的:探讨根际土壤微生物对中药材种植模式的响应方式。方法:以间作黄芪及单作下当归根际土壤为研究对象,基于高通量测序技术,分析土壤微生物在不同季节及种植模式下群落组成及功能的差异。结果:间作下Chao1指数、ACE指数高于单作,变形菌门、放线菌门、酸杆菌门、绿弯菌门和芽单胞菌门为间作下的优势菌门,芽单胞菌门的相对丰度在间作下高于单作。11月间作下γ变形菌纲、7月间作下全噬菌纲的丰度显著高于单作。KEGG功能预测表明,在不同时间及间作下根际土壤细菌与细胞过程、环境信息处理、遗传信息处理、代谢功能下属的23类二级功能基因的相对丰度存在显著差异;参与氮循环的功能基因K00371(narH/narY/nxrB)、(K00374 narI/narV)等OTU数在间作下显著高于单作;不同门、纲在间作下的共生网络比单作下连接紧密且更复杂。结论:当归间作黄芪影响土壤细菌群落组成,增加其丰富度及功能的丰富性,影响土壤氮循环能力,促进土壤微生物间的交互作用。

大豆株型与高光效育种的理论与实践——我50年大豆育种科学生涯(第一部分)

文章总结了杜维广从1975年到2024年从事大豆育种50年的研究经历,包括常规育种、高光效育种、理想株型育种、践行分子模块设计育种和全基因组QTL-allele设计育种(组合设计和基因型设计)新方法。本文系统总结了大豆株型与高光效育种的理论与实践,阐述了大豆植株是光能吸收的载体,从而株型与高光效关联;提出理想株型和理想型设计方案及其育种瓶颈,并对耐密大豆株型进行了探讨;提出高光效育种理念和技术路线及其高光效光合生理基础和高光效育种瓶颈。通过对30年高光效育种历程的总结,为从事大豆育种研究的科技人员作进一步研究提供参考。

采用自主研发的在线前处理系统同时分析脱硫废水中阴阳离子

电厂专用的全自动脱硫废水分析仪可以实现对超高浓度脱硫废水的自动化前处理以及分析,样品通过自动二步稀释,并与双系统离子色谱仪联用,对脱硫废水中的阴、阳离子同时进行检测。脱硫废水中阳离子主要有Na+、NH4+、K+、Mg2+、Ca2+,阴离子主要有F-、Cl-、NO3-、SO42-。本研究对仪器相关参数进行了验证,测试结果为,4种阴离子和5种阳离子的混合标准溶液在其线性关系内相关系数均大于0.999;4种阴离子的峰高和峰面积重复性RSD小于2.29%,5种阳离子的峰高和峰面积重复性RSD小于1.78%,实际样品中4种加标阴离子回收率在93.5%~100.2%之间;5种阳离子加标回收率在95.4%~103.8%之间。结果证明,该系统大大提高了分析效率,节省了人工成本,填补了市场空白。

植物生长调节剂对优质粳稻产量、品质与光合特性的影响

为探究植物生长调节剂对优质粳稻光合特性、产量与品质的影响,以绥粳18、垦稻12和三江6为试验材料,研究剑叶展开期喷施脱落酸(ABA)、6-苄氨基腺嘌呤(6-BA)、己酸二乙氨基乙醇酯(DA-6)、亚精胺(Spd)、3-吲哚丁酸(IBA)、3,5-二硝基水杨酸(SA)、油菜素内酯(BL)、玉米素(ZT)、三十烷醇(TRIA)、茉莉酸甲酯(MeJA)和N6-呋喃甲基腺嘌呤(KT)对水稻产量、品质和光合特性的影响。结果表明:与对照(CK)相比,喷施BL提高了抽穗后水稻干物质积累和茎鞘物质转运能力,增加了每穗粒重、千粒重、结实率和粒叶比,两年平均增产7.61%;喷施6-BA有利于延长抽穗期至蜡熟期绿叶面积持续期,改善抽穗后光合特性,增加每穗粒数、每穗粒重、千粒重和粒叶比,两年平均增产6.40%;而喷施DA-6、ZT、ABA、Spd、IBA、SA和KT的增产效果存在品种和年份间稳定性差异。在品质上,喷施DA-6和ZT提高了精米率和整精米率,改善了稻米外观品质。综上,剑叶展开期喷施BL和6-BA有利于供试品种增产,而喷施DA-6和ZT则更有利于稳产或增产前提下提质。