新疆褐牛及其肉用类型群体选育进展

新疆褐牛是以新疆地方品种牛哈萨克牛为母本,经过多品种杂交,历经数十年选育形成的乳肉兼用牛品种。随着时代的不断发展和人民对于农产品的消费亲睐,综合考虑新疆肉牛优势产区的生态环境、生产条件和接受程度,确定了新疆褐牛的选育方向和技术路线。该文主要从新疆褐牛品种培育历程、选育方向确定和肉用类型群体选育技术与进展方面进行阐述,旨在推动品种改良和品种形成,为其他肉牛新品种选育提供借鉴。

新疆褐牛导入安格斯基因后生产性能研究

[目的]试验旨在探索安新杂交牛F1代的胴体及产肉性能。[方法]在舍饲条件下,对比测定了新疆褐牛与含有50%安格斯牛血的新疆褐牛公牛在30月龄体尺体重与胴体质量指标,并对指标数据进行分析。[结果]新疆褐牛导入50%安格斯牛基因后,安新F1代杂交牛与新疆褐牛十字部高增幅-5.22%、尻长增幅-7.29%、腰角宽增幅-4.75%、髋宽增幅-6.81%;安新F1代杂交牛产肉性能增幅3.08%,腰部肉厚增幅57.43%。[结论]安新F1代杂交牛在产肉率、高档肉等商品肉牛生产上有明显优势,但在品种改良呈现劣势,提示我们要根据生产需要,针对性的进行品种改良或杂交优势利用。

新疆喀什地区塔什库尔干县牦牛产业扶贫调研报告

针对当前塔什库尔干塔吉克自治县牦牛养殖业的发展现状展开扶贫调研,分析制约塔什库尔干塔吉克自治县牦牛养殖业发展缓慢的主要制约因素,提出了加快塔什库尔干塔吉克自治县牦牛产业发展的建议,为积极有效推进、加快塔什库尔干塔吉克自治县牦牛产业的良好发展提供积极建议与对策。

新疆伊犁地区新疆褐牛与哈萨克牛群体改良效果评价分析

为评价伊犁地区新疆褐牛和哈萨克牛现有群体选育效果,本试验选取健康状况良好、符合品种特征的成年新疆褐牛、哈萨克牛成年母牛542头进行了群体体尺、体重等性状的调查,并对1.5~3岁的新疆褐牛、哈萨克牛公牛105头进行屠宰性状的调查。结果表明:新疆褐牛体高、体斜长、胸围、管围、体重与哈萨克牛差异均达到极显著水平(P<0.01),新疆褐牛体长指数、管围指数、体躯指数与成年哈萨克牛差异极显著(P<0.01),成年新疆褐牛胸围指数与成年哈萨克牛差异显著(P<0.05),新疆褐牛公牛活重、胴体重、屠宰率、眼肌面积差异极显著(P<0.01)。结论:改良前的哈萨克牛体型短小,培育后的新疆褐牛在体尺与体重指标、屠宰性状指标、体型与胸部结构发育均好于哈萨克牛。

哈萨克斯坦肉牛产业的生产、加工、消费与贸易

哈萨克斯坦是中亚地区的畜牧业大国,肉牛产业是畜牧业的支柱产业之一。为增进了解,促进交流,本篇基于FAO与相关组织公开数据就哈萨克斯坦牛业生产、消费与贸易概况等进行回顾,以期通过对哈萨克斯坦牛业的概括性阐述,为更好促进我国相关产业发展提供借鉴和参考。

吉尔吉斯斯坦畜牧业规模、结构和特点

为深入了解吉尔吉斯斯坦农牧业现状与特征,促进"一带一路"建设,采用图表法与文献调查法收集FAO统计面板数据,从宏观角度对该国畜牧业进行多维度资料收集与解读。近年来,吉尔吉斯斯坦的畜牧业取得了快速的发展,突出发展了奶牛、肉牛、马等草食家畜为主的传统优势产业,同时在畜产品需求方面,部分畜产品综合生产力水平较低,对进口产品有需求与增长潜力,畜牧业生产力水平有巨大提升空间与消费潜力,建议结合区位优势、科技优势等加大农牧业资源与技术的交流,促进农产品的贸易流通与经济发展。

新疆褐牛不同部位肉品质特性研究

为了研究新疆褐牛不同部位肉质特性,本试验选取统一饲养条件下新疆褐牛的脖肉、上脑、外脊、里脊等13个部位分别对其进行理化指标(蒸煮损失、剪切力、pH值及肉色)、营养品质(脂肪、蛋白质和水分含量)的测定及不同理化指标对大理石花纹相关性分析。结果表明,除p H值外,综合各部位理化指标、营养物质含量差异显著(P<0.05),以里脊、板腱肉质好,而辣椒条较差;大理石花纹对蒸煮损失、蛋白质含量、脂肪覆盖等级有极显著影响(P<0.01),对pH值有显著影响(P>0.05),对肉色、剪切力、BPI无显著影响。

论围产期对肉用繁殖母牛的重要性

结合肉用繁殖母牛养殖效益增长点和生产特点,确定肉用繁殖母牛的围产期为产前45 d和产后30 d,以充分适应母牛妊娠、分娩、泌乳等生理变化过程,从而确保做到一年一胎,达到提高规模牛场的繁殖水平和养殖经济效益的目的。本文从营养需要、围产期管理、影响繁育的因素等方面介绍了围产期的营养需要,归纳了围产期在预产准备、饲养管理、分娩及护理等方面的具体做法,并总结了年龄、营养、身体状况等因素对繁殖性能的影响,以期优化管理围产期各生产环节,从而改善母牛生产水平,确保后代犊牛长期健康和旺盛的生产力,为母牛围产期养殖提供参考依据。

基于隶属函数法的新疆褐牛选育效果初步评价

[目的]为客观评价研究新疆褐牛不同生产类型各阶段的生长发育特征与特点,[方法]本文基于模糊数学中的隶属函数法对新疆褐牛的重要选育指标体尺、体重等数据进行多指标综合评价与对比研究。[结果]新疆褐牛肉用类型具有体尺、体重生长发育快的特点和比较优势;新疆褐牛肉用类型与兼用类型18月龄阶段对应的隶属函数值均值为0.73和0.34,主要特征值分化明显。[结论]综合各阶段新疆褐牛体尺、体重和隶属值,在牧区开放式选育模式下新疆褐牛肉用类型生长发育快适宜性较好,各阶段中18月龄阶段表现最佳,适合作为新疆褐牛早期选育评价的重要节点。

两个玉米品种灌浆期叶片氮转移效率差异的分子机制

【目的】提高玉米氮效率是实现农业高产高效的重要措施,而花后叶片的衰老和玉米的氮效率密切相关。为此,在田间条件下研究了叶片衰老过程与氮转移效率的关系,尤其是不同玉米品种氮转移效率差异的分子机制。【方法】田间试验选择中度绿熟玉米品种先玉335 (XY335)和持绿玉米品种NE9为供试作物,设施N45,120和240 kg/hm^2三个水平。测定了玉米吐丝期以及吐丝后7 d、14 d、21 d、28 d、35 d、42 d和成熟期茎、叶、籽粒氮含量和花后绿叶面积,吐丝期及吐丝后14 d、28 d、42 d和成熟期叶片氮浓度,以及吐丝期和灌浆期叶片中SPAD、可溶性蛋白浓度、游离氨基酸浓度和ZmSee2β(玉米叶片中协同衰老的蛋白酶–豆荚蛋白的基因)基因表达的变化,计算了叶片氮转移效率。【结果】品种XY335具有比品种NE9更高的产量,随施氮量的增加品种XY335的籽粒产量较品种NE9增加更加显著。虽然两个品种的收获指数没有差异,但是品种XY335的氮素收获指数高于品种NE9,并且品种XY335营养器官的氮转移效率高于品种NE9,整体高8.28个百分点(P <0.05)。品种XY335叶片氮转移效率比品种NE9高出12.89个百分点,而二者茎的氮转移效率没有差异。品种XY335花后叶片中氮浓度开始降低的时间早于品种NE9,在低氮条件下尤为明显。成熟期时,三个氮水平处理下品种XY335叶片中的氮含量均低于品种NE9。从吐丝期到灌浆期,品种XY335叶片中可溶性蛋白的降解率高于品种NE9,其中N45处理下高16.5个百分点,N120处理下高6.2个百分点。从吐丝期到灌浆期叶片中游离氨基酸的浓度不断增加,而品种XY335叶片中的增加幅度大于品种NE9。从吐丝期到灌浆期叶片中ZmSee2β基因表达量增加,而随施氮量减少品种XY335叶片中表达量高于品种NE9,表明品种XY335叶片中蛋白降解得更加迅速。【结论】相对于绿熟品种NE9,品种XY335具有籽粒产量高和籽粒氮素积累强的特点。这不仅由于吐丝后品种XY335具有较强的氮素吸收能力,而且因为品种XY335有更高的叶片氮转移效率。品种XY335叶片氮转移效率高可能是因为控制蛋白质降解的ZmSee2β基因表达能力强,提高了叶片中蛋白质的降解速度。

分子育种技术研究进展及新疆肉牛分子育种现状

经济社会的发展使人们对牛肉的经济性和肉品质要求提高,培育生长性能和生产性能更加良好的肉牛品种的重要性日益凸显。随着分子生物学技术的进步,动物育种逐渐从表型性状研究向基因调控发展,通过分子标记辅助育种能够更加快速准确的选择目标性状,分子育种技术提高了品种培育效率并降低了成本,且繁育的后代优良性状更加稳定,其应用范围也越来越广泛。目前新疆肉牛分子育种的应用较少,多停留在理论研究阶段,且存在着经费不足和育种场规模小、难以获得足够的样本等问题。本文综合阐述了分子育种的概述、肉牛分子育种研究进展和新疆肉牛分子育种现状,旨在为新疆肉牛分子育种工作提供一定的思路和理论依据。

Interaction effect of nitrogen form and planting density on plant growth and nutrient uptake in maize seedlings

High planting density is essential to increasing maize grain yield.However,single plants suffer from insufficient light under high planting density.Ammonium(NH_4^+)assimilation consumes less energy converted from radiation than nitrateIt is hypothesized that a mixed NO_3~–/NH_4^+supply is more important to improving plant growth and population productivity under high vs.low planting density.Maize plants were grown under hydroponic conditions at two planting densities(low density:only).A significant interaction effect was found between planting density and N form on plant biomass.Compared to nitrate only,75/25NO_3~–/NH_4^+increased per-plant biomass by 44%under low density,but by 81%under high density.Treatment with 75/25NO_3~–/NH_4^+increased plant ATP,photosynthetic rate,and carbon amount per plant by 31,7,and 44%under low density,respectively,but by 51,23,and 95%under high density.Accordingly,carbon level per plant under 75/25NO_3~–/NH_4^+was improved,which increased leaf area,specific leaf weight and total root length,especially for high planting density,increased by 57,17 and 63%,respectively.Furthermore,under low density,75/25NO_3~–/NH_4^+increased nitrogen uptake rate,while under high density,75/25NO_3~–/NH_4^+increased nitrogen,phosphorus,copper and iron uptake rates.By increasing energy use efficiency,an optimum NO_3~–/NH_4^+ratio can improve plant growth and nutrient uptake efficiency,especially under high planting density.In summary,an appropriate supply of NH_4^+in addition to nitrate can greatly improve plant growth and promote population productivity of maize under high planting density,and therefore a mixed N form is recommended for high-yielding maize management in the field.

Genetic Improvement of Root Growth Contributes to Efficient Phosphorus Acquisition in maize (Zea mays L.)

Maize plants adapt to low phosphorus （P） stress by increasing root growth. It is of importance to know the extent to which genetic improvement of root growth can enhance P acquisiton. In the present study, the contribution of root growth improvement to efficient P acquisition was evaluated in two soils using T149 and T222, a pair of near isogenic maize testcrosses which were derived from a backcross BC 4 F 3 population. T149 and T222 showed no difference in shoot biomass and leaf area under normal growth conditions, but differed greatly in root growth. T149 had longer lateral roots and a larger root surface area compared to T222. In calcareous soil, when P was insufficient, i.e., when P was either supplied as KH 2 PO 4 at a concentration of 50 mg P kg-1 soil, or in the form of Phy-P, Ca3-P or Ca10-P, a 43% increase in root length in T149 compared to T222 resulted in an increase in P uptake by 53%, and shoot biomass by 48%. In acid soil, however, when P supply was insufficient, i.e., when P was supplied as KH 2 PO 4 at a concentration of 100 mg P kg-1 soil, or in the form of Phy-P, Fe-P or Al-P, a 32% increase in root length in T149 compared to T222 resulted in an increase in P uptake by only 12%, and shoot biomass by 7%. No significant differences in the exudation of organic acids and APase activity were found between the two genotypes. It is concluded that genetic improvement of root growth can efficiently increase P acquisition in calcareous soils. In acid soils, however, improvements in the physiological traits of roots, in addition to their size, seem to be required for efficient P acquisition.

Cell Production and Expansion in the Primary Root of Maize in Response to Low-Nitrogen Stress

Maize plants respond to low-nitrogen stress by enhancing root elongation. The underlying physiological mechanism remains unknown. Seedlings of maize （Zea mays L., cv. Zhengdan 958） were grown in hydroponics with the control （4 mmol L-1） or low-nitrogen （40 μmol L-1） for 12 d, supplied as nitrate. Low nitrogen enhanced root elongation rate by 4.1-fold, accompanied by increases in cell production rate by 2.2-fold, maximal elemental elongation rate （by 2.5-fold）, the length of elongation zone （by 1.5-fold）, and ifnal cell length by 1.8-fold. On low nitrogen, the higher cell production rate resulted from a higher cell division rate and in fact the number of dividing cells was reduced. Consequently, the residence time of a cell in the division zone tended to be shorter under low nitrogen. In addition, low nitrogen increased root diameter, an increase that occurred speciifcally in the cortex and was accompanied by an increase in cell number. It is concluded that roots elongates in response to low-nitrogen stress by accelerating cell production and expansion.

Local nitrogen application increases maize post-silking nitrogen uptake of responsive genotypes via enhanced deep root growth

Nitrogen(N)is unevenly distributed throughout the soil and plant roots proliferate in N-rich soil patches.However,the relationship between the root response to localized N supply and maize N uptake efficiency among different genotypes is unclear.In this study,four maize varieties were evaluated to explore genotypic differences in the root response to local N application in relation to N uptake.A split-root system was established for hydroponically-grown plants and two methods of local N application(local banding and local dotting)were examined in the field.Genotypic differences in the root length response to N were highly correlated between the hydroponic and field conditions(r>0.99).Genotypes showing high response to N,ZD958,XY335 and XF32D22,showed 50‒63%longer lateral root length and 36‒53%greater root biomass in N-rich regions under hydroponic conditions,while the LY13 genotype did not respond to N.Under field conditions,the root length of the high-response genotypes was found to increase by 66‒75%at 40‒60 cm soil depth,while LY13 showed smaller changes in root length.In addition,local N application increased N uptake at the post-silking stage by 16‒88%in the high-response genotypes and increased the grain yield of ZD958 by 10‒12%.Moreover,yield was positively correlated with root length at 40‒60 cm soil depth(r=0.39).We conclude that local fertilization should be used for high-response genotypes,which can be rapidly identified at the seedling stage,and selection for“local-N responsive roots”can be a promising trait in maize breeding for high nitrogen uptake efficiency.

Phenotypic characterization and genetic mapping of the dwarf mutant m34 in maize

Plant height is one of the most important agronomic traits associated with yield in maize.In this study,a gibberellins(GA)-insensitive dwarf mutant,m34,was screened from inbred line Ye478 by treatment with the chemical mutagen ethylmethanesulfonate(EMS).Compared to Ye478,m34 showed a dwarf phenotype with shorter internodes,and smaller leaf length and width,but with similar leaf number.Furthermore,m34 exhibited smaller guard cells in internodes than Ye478,suggesting that smaller cells might contribute to its dwarf phenotype.Genetic analysis indicated that the m34 dwarf phenotype was controlled by a recessive nuclear gene.An F2 population derived from a cross between m34 and B73 was used for mutational gene cloning and this gene was mapped to a chromosome region between umc2189 and umc1553 in chromosome 1 bin1.10,which harbored a previously identified dwarf gene Zm VP8.Sequencing analysis showed a nucleotide substitution(G1606 to A1606)in the sixth exon of ZmVP8,which resulted in an amino acid change(E531 to K531)from Ye478 to m34.This amino acid change resulted in anα-helix changing to aβ-sheet in the secondary protein structure and the‘SPEC’domain changed to a‘BOT1NT’domain in the tertiary protein structure.Taken together,these results suggested that m34 is a novel allelic mutant originally derived from Ye478 that is useful for further ZmVP8 functional analysis in maize.

Transcriptional Regulation of Expression of the Maize Aldehyde Dehydrogenase 7 Gene (ZmALDH7B6) in Response to Abiotic Stresses

Aldehyde dehydrogenases（ALDHs） represent a large protein family, which includes several members that catalyze the oxidation of an aldehyde to its corresponding carboxylic acid in plants. Genes encoding members of the ALDH7 subfamily have been suggested to play important roles in various stress adaptations in plants. In this study, quantitative RT-PCR analysis revealed that a maize ALDH7 subfamily member（ZmALDH7B6） was constitutively expressed in various organs, including roots, leaves, immature ears, tassels, and developing seeds. The abundance of ZmALDH7B6 mRNA transcripts in maize roots was increased by ammonium, NaCl, and mannitol treatments. To further analyze tissue-specific and stress-induced expression patterns, the 1.5-kb 5′-flanking ZmALDH7B6 promoter region was fused to the β-glucuronidase（GUS） reporter gene and introduced into maize plants. In roots of independent transgenic lines, there was significant induction of GUS activity in response to ammonium supply, confirming ammonium-dependent expression of ZmALDH7B6 at the transcript level. Histochemical staining showed that GUS activity driven by the ZmALDH7B6 promoter was mainly localized in the vascular tissues of maize roots. These results suggested that ZmALDH7B6 is induced by multiple environmental stresses in maize roots, and may play a role in detoxifying aldehydes, particularly in vascular tissue.

新疆某肉牛养殖场不同架子牛育肥模式的经济效益分析

本研究通过对新疆某肉牛养殖场架子牛育肥经济效益的调研分析,旨在为新疆肉牛养殖从业者选择架子牛育肥模式提供理论参考。购入高、低初始重的新疆褐牛与本地土牛杂交架子牛各24头,分为高成本高初始重组(HH组)、低成本高初始重组(LH组)、高成本低初始重组(HL组)、低成本低初始重组(LL组),每组12头牛,育肥周期为7-9个月,每月称重并记录结果,并对数据进行分析。单因素方差分析结果显示,LL组末重极显著低于其它3组(P<0.01),HH组末重显著高于LH组和HL组(P<0.05);育肥期平均日增重LL组显著低于其它3组(P<0.05),HH组、LH组和HL组虽然差异不显著(P>0.05),但是HH组和HL组日增重大于LH组。经济效益分析结果显示,成本利润率HL组>HH组>LL组>LH组。相关性分析结果显示,成本利润率与平均日增重呈极显著正相关关系(P<0.01),与日饲喂成本呈现显著正相关关系(P<0.05)。本研究发现,在架子牛育肥过程中,高饲喂成本投入可以获得更高的经济效益,选择低初始重的架子牛进行短期高营养水平育肥,比选择高初始重的架子牛育肥经济效益更好。

Ammonium-dependent regulation of ammonium transporter ZmAMT1s expression conferred by glutamine levels in roots of maize

In maize,two root epidermis-expressed ammonium transporters ZmAMT1;1a and ZmAMT1;3 play major roles in highaffinity ammonium uptake.However,the transcriptional regulation of ZmAMT1s in roots for ensuring optimal ammonium acquisition remains largely unknown.Here,using a split root system we showed that ZmAMT1;1a and ZmAMT1;3transcript levels were induced by localized ammonium supply to nitrogen-deficient roots.This enhanced expression of Zm AMT1s correlated with increases in ^(15)NH_(4)^(+)influx rates and tissue glutamine concentrations in roots.When ammonium was supplied together with methionine sulfoximine,an inhibitor of glutamine synthase,ammonium-induced expression of ZmAMT1s disappeared,suggesting that glutamine rather than ammonium itself regulated ZmAMT1s expression.When glutamine was supplied to nitrogen-deficient roots,expression levels of ZmAMT1s were enhanced,and negative feedback regulation could subsequently occur by supply of glutamine at a high level.Thus,our results indicated an ammonium-dependent regulation of ZmAMT1s at transcript levels,and a dual role of glutamine was suggested in the regulation of ammonium uptake in maize roots.

基于PDCA模式的医院科研实验室安全管理实践

目的:应用PDCA模式进行实验室安全管理,以发现和整改安全管理过程中存在的隐患和问题,提高安全管理效率。方法:以我院23个科研实验室为研究对象,比较PDCA安全管理模式实施前后5项核心安全指标的改进情况。结果:实施PDCA安全管理模式后,所有实验室的5项安全指标的合格率均显著高于实施前,差异均具有统计学意义。结论:应用PDCA管理方法,能有效提高实验室安全管理质量,减少实验室安全隐患,保障实验室人员的职业安全。