Genome-wide association mapping and genomic prediction of stalk rot in two mid-altitude tropical maize populations

Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection.We performed a genome-wide association study(GWAS)and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpe?o and non-Tuxpe?o heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms(SNPs).Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses.More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines.Incorporating genotype-by-environment(G×E)interaction increased genomic prediction accuracy.

Dissecting the genetic architecture of glucosinolate compounds for quality improvement in flowering stalk tissues of Brassica napus

Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.

Improvement of Methane Production from Corn Stalk for Whole Slurry Anaerobic Co-digestion Under Hydrothermal Wastewater Pretreatment

Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance.

Genome-wide association study identifies novel candidate loci or genes affecting stalk strength in maize

Stalk strength increases resistance to stalk lodging,which causes maize(Zea mays L.)production losses worldwide.The genetic mechanisms regulating stalk strength remain unclear.In this study,three stalk strength-related traits(rind penetrometer resistance,stalk crushing strength,and stalk bending strength)and four plant architecture traits(plant height,ear height,stem diameter,stem length)were measured in three field trials.Substantial phenotypic variation was detected for these traits.A genome-wide association study(GWAS)was conducted using general and mixed linear models and 372,331 single-nucleotide polymorphisms(SNPs).A total of 94 quantitative trait loci including 241 SNPs were detected.By combining the GWAS data with public gene expression data,56 candidate genes within 50 kb of the significant SNPs were identified,including genes encoding flavonol synthase(GRMZM2G069298,ZmFLS2),nitrate reductase(GRMZM5G878558,ZmNR2),glucose-1-phosphate adenylyltransferase(GRMZM2G027955),and laccase(GRMZM2G447271).Resequencing GRMZM2G069298 and GRMZM5G878558 in all tested lines revealed respectively 47 and 2 variants associated with RPR.Comparison of the RPR of the zmnr2EMS mutant and the wild-type plant under high-and low-nitrogen conditions verified the GRMZM5G878558 function.These findings may be useful for clarifying the genetic basis of stalk strength.The identified candidate genes and variants may be useful for the genetic improvement of maize lodging resistance.

MUTS-Based Cooperative Target Stalking for A Multi-USV System

This paper is concerned with the cooperative target stalking for a multi-unmanned surface vehicle(multi-USV)system.Based on the multi-agent deep deterministic policy gradient(MADDPG)algorithm,a multi-USV target stalking(MUTS)algorithm is proposed.Firstly,a V-type probabilistic data extraction method is proposed for the first time to overcome shortcomings of the MADDPG algorithm.The advantages of the proposed method are twofold:1)it can reduce the amount of data and shorten training time;2)it can filter out more important data in the experience buffer for training.Secondly,in order to avoid the collisions of USVs during the stalking process,an action constraint method called Safe DDPG is introduced.Finally,the MUTS algorithm and some existing algorithms are compared in cooperative target stalking scenarios.In order to demonstrate the effectiveness of the proposed MUTS algorithm in stalking tasks,mission operating scenarios and reward functions are well designed in this paper.The proposed MUTS algorithm can help the multi-USV system avoid internal collisions during the mission execution.Moreover,compared with some existing algorithms,the newly proposed one can provide a higher convergence speed and a narrower convergence domain.

Using Sorghum Stalk as a Partial Replacement of Lime in the Stabilization of Red Clay Soil for Road Sub-Grade Construction

This research aimed at testing the viability of using Sorghum Stalk Ash (SSA) as a partial replacement of lime in the stabilization of red clay soils for road subgrade construction. Red clay soils have been identified as highly expansive soils, which are affected by both climatic conditions and loading patterns. The consideration of both traffic loading patterns and climatic effects on these soils has been taken into account. A penetration test of 2.5 mm has been used on both pure red soils and stabilized soils at 10% and 15% partial replacement of lime with SSA and showed an improvement in the CBR of stabilized red clay soils up to 11.6%. Again, the PI of stabilized soils at 15% partial replacement of lime reduced up to 11.2%. The results obtained on both CBR and PI of these red clay soils are within the recommended values for the effective subgrade required for laying both permanent and flexible pavements. As a result, a recommendation of making use of SSA to lower the quantities of lime and its costs used in the stabilization of highly expansive soils have been tested through this research. However, further research on a more percentage partial replacement of lime to improve the PI of these soils to below 10% while keeping the CBR levels within the road construction regulations is welcomed.

玉米秸秆堆腐还田对黑土区土壤性状的影响

本研究针对东北地区秋冬季节气候寒冷特点和秸秆堆腐还田的实际操作需求,开展秸秆堆腐还田试验。在秋季玉米收获之后进行田间堆腐试验,期间连续监测环境温度、降水、秸秆堆温度、秸秆失重率等指标。离田玉米秸秆经过腐熟后作为肥料还田,连续施用3年,检测土壤有机质、碱解氮、速效磷、速效钾、土壤孔隙度、土壤容重等指标。在基本农田和棚室保护地进行为期2年的应用试验。结果表明:120 d秸秆失重率达到31.53%。施用腐熟秸秆3年,土壤有机质提高了4.06~6.31 g/kg、土壤中碱解氮提高了15.08~27.35 mg/kg、速效磷提高了18.11~21.95 mg/kg、速效钾提高63.97~89.93 mg/kg;土壤容重降低了0.10~0.14 g/cm^(3)、土壤田间持水量提高了7.51%~9.24%(V/V)、土壤孔隙度提高了3.69%~5.27%(V/V),且差异显著(P≤0.05)。基本农田和棚室保护地应用试验中,速效养分与有机质有所增长,土壤容重与田间持水量变化显著。逐年施用腐熟秸秆对于提高土壤有机质含量、速效养分具有显著作用。同时,施用腐熟秸秆能够降低土壤容重,提高土壤孔隙度与田间持水量,改善土壤板结问题。腐熟秸秆在改良与保育黑土性质方面具有良好的作用。

辽宁省玉米秸秆基质栽培糙皮侧耳菌株筛选评价

为筛选出适宜辽宁地区以玉米秸秆为主要栽培基质的优良糙皮侧耳菌株,以19个糙皮侧耳菌株为试验材料,对菌丝长势、满袋时间、污染率、生物学效率及农艺性状等指标进行测定和比较分析。结果表明,C14号菌株综合指标优于其他供试菌株,其母种和栽培种在玉米秸秆基质中菌丝长势均较好,生物学效率较高,为105.8%,子实体菌盖颜色深灰色,菌柄3.1~6.8 cm,朵大韧性好,菇型紧凑,菌盖肥厚,中等大小,光泽好,可作为生产用优良菌株。C10、C2号菌株子实体性状一般,但其母种及栽培种在玉米秸秆基质中菌丝长势强、生物学效率高,利用秸秆能力强,可作为品种选育的备选材料。

玉米秸秆中7种游离单糖的高效液相色谱测定方法

本研究旨在建立一种测定玉米秸秆中7种游离单糖[D(+)-葡萄糖、L-鼠李糖、D(+)-木糖、L-阿拉伯糖、D(-)-核糖、D(+)-半乳糖和D(+)-甘露糖]的高效液相色谱测定方法。将玉米秸秆在60℃干燥后粉碎,以水作为提取溶剂,98℃水浴提取1 h,冷却后离心取上清液;利用1-苯基-3-甲基-5-吡唑啉酮(PMP)衍生化处理,上清液过0.22μm滤膜,以Agilent Zorbax SB-C_(18)色谱柱进行高效液相色谱分析,7种组分在56 min内达到分离。结果表明:D(+)-葡萄糖、L-鼠李糖、D(+)-木糖、L-阿拉伯糖、D(-)-核糖、D(+)-半乳糖和D(+)-甘露糖的保留时间和峰面积的日内相对标准偏差均分别小于1.0%和5.0%,日间相对标准偏差均分别小于1.0%和7.5%;线性范围分别为0.31~2 000μg/mL、 0.31~200μg/mL、 0.50~200μg/mL、0.75~200μg/mL、0.31~200μg/mL、0.75~200μg/mL和0.31~200μg/mL,线性关系良好,相关系数均达到0.999以上;检出限为0.10~0.25μg/mL,加标回收率为79.9%~114.8%。由此可见,本研究建立的方法不仅操作简单,还可以对玉米秸秆中的7种游离单糖准确定量,为研究玉米秸秆中糖类物质含量以及在动物体内的消化吸收提供技术支撑。

油菜薹中啶虫脒残留质控样品的制备与评价

为保障油菜薹中啶虫脒农药残留快速检测结果的准确性和可靠性,建立油菜薹中啶虫脒质控样品的制备方法并进行评价。采用基质加标、真空冷冻干燥的方法制备冻干质控样品。采用液相色谱质谱串联的检测方法对质控样品中的啶虫脒含量进行测定,通过随机抽样检验以评估样品的均匀性,通过观察质控样品在一个月内啶虫脒含量变化以评估样品的稳定性。该方法制备的油菜薹中啶虫脒农药残留质控样品均匀性和稳定性良好,便于储存和运输,适用于快检产品验证、盲样考核等快速检测领域。本研究建立了一种流程简单的油菜薹冻干粉质控样品制备方法,为蔬菜中农药残留质控样品制备共性关键技术研究提供了数据参考。

大豆皂脚与玉米秸秆厌氧发酵沼渣共热解特性及应用

将大豆皂脚与玉米秸秆厌氧发酵沼渣两种固体废弃物以不同比例混合后进行共热解,采用元素分析、扫描电子显微镜(SEM)、N_2吸附-脱附法(BET)对得到的共热解炭进行表征,并将共热解炭循环应用到玉米秸秆厌氧发酵环境中,考察共热解炭对厌氧发酵过程的影响。结果表明:共热解炭的产率随着沼渣加入量的增大而增大;沼渣加入量较少时,可以促进共热解气的生成,但对共热解液的产生有较弱的抑制作用;共热解炭的比表面积和平均孔径介于两种单一热解炭之间,并且平均孔径随沼渣加入量的增大呈减小趋势;将大豆皂脚与沼渣的质量比为4∶3下制备的共热解炭加入厌氧发酵系统中,发酵30 d时累积产气量达到390.80 mL/g,累积产甲烷量达到213 mL/g,累积产气量达到总产气量80%所需要的时间t_(80)为(14±1) d,比不添加热解炭的空白组提前了12.5%。

木霉微生物菌肥的制备及对玉米茎腐病的应用评价

以前期分离鉴定的生防菌株非洲哈茨木霉Tr35为研究对象,通过载体的筛选,制备木霉菌剂和木霉微生物菌肥。通过测定不同含量的木霉菌剂和木霉有机肥的株高、根长和鲜重,筛选促生效果明显的处理,并通过室内盆栽试验,评价其对玉米苗期茎腐病的防效。结果显示,玉米秸秆粉具有吸水性强、对Tr35无毒和高释放率的优点,与Tr35共同发酵制备木霉菌剂,当土与菌剂为5∶1时,促生效果明显,并对玉米苗期茎腐病防效达51.77%。菌剂土与腐熟羊粪为7∶1时的木霉有机肥促生效果最好,以该比例制备木霉微生物菌肥,对玉米苗期茎腐病防效达61.31%,该研究结果为Tr35菌剂和菌肥的应用开发提供了一定的前期基础。

玉米秸秆复合高吸水树脂的制备及对Pb^(2+)的吸附研究

以来源丰富的玉米秸秆、高岭土为原料,以丙烯酸、丙烯酰胺为聚合单体,通过水溶液聚合法制备了复合高吸水树脂,并用红外光谱(FT-IR)和扫描电镜(SEM)对其结构进行了表征分析。利用合成的复合高吸水树脂对含Pb^(2+)模拟废水进行了吸附研究,考察了复合高吸水树脂用量、Pb^(2+)初始浓度、吸附时间和溶液pH及对Pb^(2+)去除率的影响,最优条件下复合高吸水树脂对Pb^(2+)的去除率达88.57%,吸附Pb^(2+)后的复合高吸水树脂经处理后可循环使用。

棉秆和油页岩共热解生物炭的氨氮吸附性能研究

使用棉秆(CS)和油页岩(OS)为原料,采用共热解的方式制备了共热解生物炭,探究了对氨氮的吸附性能。考察了不同热解时间、CS和OS比例、热解温度、CS的粒径对共热解生物炭的氨氮吸附量的影响规律,确定了最佳制备条件,并研究了吸附动力学和吸附等温线模型。研究表明,棉秆和油页岩共热解后生物炭的结构特性和表面形貌有较大改善,对氨氮的吸附能力有明显的提高。最佳的制备条件是热解温度为500℃、m(棉秆)∶m(油页岩)=3∶1、热解时间为30 min和CS的粒径为0.20~0.30 mm。在投加量为10.0 g/L、pH 9.0时,最佳条件所制备炭的吸附量为4.89 mg/g,是棉秆生物炭的2.2倍。吸附过程以准二级动力学和Langmuir等温吸附模型描述。吸附机制主要包括为离子交换、静电吸附和配位作用。

快速和慢速热解对棉秆生物炭理化特性及土壤持水量的影响

以新疆棉秆为原料,在300~700℃下利用快速和慢速热解方式制备了生物炭,研究了快速和慢速热解对棉秆生物炭形貌、表面官能团、pH值、元素组成的影响.利用室内土柱试验,研究了不同条件下制备的生物炭对土壤持水量的影响.结果表明:1)随着热解温度的升高,生物炭产率下降,pH值提高,孔隙度增加.快速热解生物炭具有孔隙发达、芳香性高、稳定性强的优点.2)土壤持水量随着生物炭添加量和热解温度的升高而提高.生物炭添加量为0.03 g/g时,土壤持水量分别为51.7%和49.7%,比未添加生物炭提高了32.5%和27.4%.3)添加生物炭土壤15 d后保水量仍有40.3%,远高于纯土壤,且添加快速热解生物炭的土壤保水量高于慢速热解生物炭.

玉米秸秆刨花板压制工艺优化及吸水厚度膨胀率

农作物秸秆用作人造板原材料,可减少环境污染,缓解木材供需紧张,秸秆中纤维素与木质素含量可以满足人造板生产要求。以玉米秸秆刨花为原料,在一定热压压力、热压时间、刨花密度、热压温度下,采用不同施胶量无机胶黏剂压制玉米秸秆刨花板,探索最优工艺参数及玉米秸秆刨花板吸水厚度膨胀率变化规律。结果显示:压制玉米秸秆刨花板的最优工艺参数为刨花含水率12%、热压压力1.6MPa、热压时间9min、刨花密度1.0g/cm^(3)、施胶量20%、热压温度90℃;影响玉米秸秆刨花板吸水厚度膨胀率的因素依次为刨花含水率>热压压力>热压时间>刨花密度>施胶量>热压温度。试验结果表明:在吸水厚度膨胀率合格的前提下,玉米秸秆刨花板的内结合强度、弹性模量、静曲强度均符合国家标准规定的性能要求。

瓜蒂散证浅析

瓜蒂散证病机为邪气在肺,与正气向外交争,其势向外,以瓜蒂作用于中焦,借其春木之性,配合酸平之赤小豆,辛香之淡豆豉,越上而吐,则病可解。脉弦而有力、脾胃不虚者,用之最宜;肝虚者,可加竹茹,柴胡等;若恐伤胃气,可加生麦芽顾脾胃而调肝。应用时需与三物白散证和十枣汤证相鉴别,瓜蒂散证多见弦脉,三物白散证寒实较瓜蒂散证重,脉多沉迟,若化脓亦可见数脉。十枣汤证多喘咳日久,面目浮肿,倚息不得卧,以咳嗽或用力牵引疼痛加剧为鉴别点。《伤寒论》第108条所言之腹满谵语,寸口脉浮而紧亦是痰饮结于胸所致,可用瓜蒂散吐出胸中之邪,使上下交通,诸症得解。无论是寒痰、热痰等实邪,或是宿食、误食毒物等所致结胸之证,皆可谨遵脉证使用瓜蒂散,服后未必呕吐,不断咳吐痰涎即为对证。

新疆棉花经济效益及其副产物在动物养殖中的饲用价值

新疆棉花产业蓬勃发展,其副产物棉秆和棉籽粕在动物养殖中扮演着重要角色。棉秆为干旱地区珍贵饲料,可提供必要营养并保障畜群健康。棉籽粕是高质量饲料原料,含丰富的蛋白质和营养成分,助推畜禽生长发育。合理利用这些副产物不仅可以提升饲料品质,也可增强动物生产性能。尽管需进一步加强研发与推广,以提高利用率和降低生产成本,但深入挖掘棉秆和棉籽粕在畜牧业的潜在价值有助于提升经济效益,促进畜牧业可持续发展。

氮气和含氧气氛下玉米秸秆热解气化产气规律研究

为了探究秸秆类生物质在热解和气化过程中的产气规律,以我国东北地区典型的玉米秸秆为原料,基于自行建立的管式炉生物质热解气化实验装置,系统研究了玉米秸秆在氮气气氛下热解和在含氧气氛下气化过程中CO、H_(2)、CO_(2)、CH_(4)和C_(n)H_(m)等小分子生物质燃气成分的释放特性,对比分析了不同热解温度和气化温度对不同燃气组分释放规律及其产率的影响。实验结果表明:玉米秸秆热解过程中最先释放的小分子气相产物是CO和CO_(2);当温度升高时生物质燃气中逐渐出现CH4和H2,且随着热解温度升高,CO的产率峰值最先出现且峰值出现在升温阶段,而CO_(2)、CH_(4)和H_(2)的产率峰值几乎同时出现在恒温阶段;热解温度升高,玉米秸秆热解产生的CO体积分数几乎没有变化,而CO_(2)的占比则随着温度的升高而降低;在400~500℃之间CH_(4)体积分数随着热解温度的升高而增加,在500℃以后,基本稳定在13%。在O_(2)体积分数为8%、N_(2)体积分数为92%的含氧气氛下,随着气化温度的升高,玉米秸秆气化产生CO_(2)气体的体积分数呈先增加后降低的趋势,而CO的体积分数随着温度的升高而增大,这说明高温气化条件下更有利于CO的释放,而低温条件下有利于CO_(2)的产生。

罗布麻秆中纤维素提取及其气凝胶的制备

为实现罗布麻秆的高附加值利用,以罗布麻秆为原料,选用硝酸/乙醇法提取纤维素,通过单因素试验和正交试验优化的提取工艺为:温度85℃、时间1.5 h和固液比1∶25,提取的纤维素纯度可达98.61%。采用TEMPO氧化与超声处理相结合,制备纳米纤维素;再以其为骨架,加入聚乙烯醇和钠基蒙脱土制备纤维素复合气凝胶(NMPC)。结果表明:与纤维素气凝胶(PC)相比,NMPC对亚甲基蓝(MB)的吸附量最高达265.84 mg/g。当应变为60%时,NMPC的应力是PC的2倍。钠基蒙脱土的加入改善了气凝胶的结构,不仅提高了气凝胶的吸附性能,还提升了其压缩力学性能。