Field Experiment for the Effects of Rice Straw Returning and Seeding Pattern on Wheat Seedling Emergence and Grain Yield

In order to study the effect of rice straw returning and seeding patterns on seedling emergence and grain yield, field experiment was conducted to investi- gate the effects of straw mechanized returning and different seeding patterns on e- mergence rate, emergence uniformity and yield traits of wheat after rice. The results were as follows： in rice straw removal treatments, the emergence rate of mechani- cal seeding in drill was lower than that of mechanical uniform planting and manual broadcast sowing, which were 51.84%, 90.89% and 88.87%, respectively; the emer- gence uniformity of manual broadcast sowing was inferior to mechanical seeding in drill and mechanical uniform planting, which were 0.49, 0.26 and 0.23, respectively. As for the treatments with rice straw returning to the field, the emergence rate and emergence uniformity all decreased in the three seeding patterns, of which mechan- ical seeding in drill dropped markedly with emergence rate decreased by 36.54%. The emergence rate and emergence uniformity affected grain yield by affecting pan- icle, grains per spike and 1 000-grain weight. The grain yield for the treatment with rice straw removal was 6 091.34 kg/hm2, while that with rice straw returning to field was 6 476.20 kg/hm2, and both were higher than the yields of the other two seed- ing patterns. Therefore, mechanical uniform planting was？recommended for its higher emergence rate, better emergence uniformity, which was conductive to increase grain yield in wheat after rice production with rice straw returning to field.

Spatial pattern and utility of Populus euphratica seed rain:a simulation study combined with field investigations

Seed dispersal is a fundamental process affecting destinies of seeds and seedlings, as well as regeneration dynamics and distribution patterns of communities. Recently however, declining Populus euphratica forests have failed to regenerate by seeding, while the spatial pattern and utility of their seed rains are unclear. In this study, we designed a model to simulate seed rains based on field investigations by fitting our observations to a normal distribution and testing the model with data from three years, with ac- ceptable results. We examined the simulated results of dispersed seeds patterns on the classification of three factors, i.e., density of Sophora alopecuroides, surface soil moisture and surface soil salinity. The results of seed rain simulation show that over 70% of seeds were dispersed and confined to each of the three plots where their mother trees located. The proportion of 3：7 seeds dispersed inside and outside each plots remained largely unaltered. The differences in the amounts of dispersed seed among the different levels of each of the factors were not significant, although the distributing pattern of P. euphratica in each plot varied. Therefore, in P. eu- phratica communities, the amount of seed does not become a constraint in subsequent germination, although the surface environment does. We conclude that successful P. euphratica seed regeneration relies on less than 30% of seeds dispersed over longer distance to colonize favorable growth habitats.

垄上交错种植密度对花生群体生长及产量的影响

为构建高产花生群体模式,根据花生品种类型调整垄上交错单粒种植模式下的合理种植密度。以半匍匐型花生品种扶余四粒红和直立型花生品种吉花17为材料,研究垄上交错单粒种植密度对花生植株性状、群体结构变化及产量的影响。共设置6个种植密度M1(23.85万株/hm^(2))、M2(20.84万株/hm^(2))、M3(18.52万株/hm^(2))、M4(16.66万株/hm^(2))、M5(13.89万株/hm^(2))、M6(11.91万株/hm^(2)),以双粒播种(23.85万株/hm^(2))为对照(CK)。对不同种植密度下各花生品种的植株性状、SPAD值、单株干物质积累量及产量性状等进行测定。随着种植密度的降低,两品种主茎高和侧枝长逐渐增高,半匍匐型花生品种四粒红在M6密度下的主茎高和侧枝长最高,直立型花生品种吉花17会随着种植密度的降低而先增加后降低的趋势,在M5密度下的主茎高和侧枝长最高。随着种植密度的降低,两品种在结荚期和成熟期的SPAD值呈先下降后上升的趋势。四粒红成熟期M4、M5、M6处理的地上和地下单株干物质积累量均显著高于CK。吉花17在生育后期M4处理下的地上和地下单株干物质积累量较CK有显著提升,成熟期分别较对照提高了155.35%、23.31%。此外,随着密度的降低,四粒红的产量呈先上升后下降的趋势,单株饱果数、百果质量和单株荚果产量均呈上升后下降的趋势,千克果数各密度处理低于CK;吉花17的产量整体上呈下降的趋势,单株饱果数、单株荚果产量均呈上升趋势,千克果数各处理均小于CK。垄上交错+单粒播种种植模式相对于双粒种植模式可以增加花生株高、SPAD值、干物质积累量,同时提高了产量。应用垄上交错种植时,应根据花生品种类型选择适宜的播种密度,半匍匐型花生品种以M4密度最佳,直立型花生品种以M2密度最佳。

不同生长年限及生长环境下黄芪种子品质评价研究

为探究不同生长年限(三年生、四年生、五年生)及生长环境(野生阳坡、野生阴坡、人工阳坡、人工阴坡)对黄芪种子抗氧化酶活性及内源性营养物质含量的影响,本研究以不同生长年限及生长环境下蒙古黄芪种子为试验材料,测定其抗氧化酶(SOD、POD、CAT)活性、过氧化氢酶(CAT)活性、丙二醛(MDA)含量以及可溶性糖、粗脂肪、蛋白质含量等指标,对黄芪种子品质进行评价分析。结果表明,蒙古黄芪种子随着生长年限的增加,其抗氧化酶(SOD、POD、CAT)活性呈增长趋势,MDA含量呈下降趋势,内源性营养物质呈上升趋势;野生黄芪种子的抗逆性要优于仿野生黄芪;阳坡种植的黄芪种子品质优于阴坡;蒙古黄芪种植留种宜选择四年生、五年生阳坡植株,其中野生黄芪最佳。

不同种植模式对柠条种实害虫危害的影响

在宁夏荒漠沙化区,人工固沙先锋植物柠条的常见种植模式有散生种植、条带化种植和密集种植3种。目前,已报道该区域柠条上的种实害虫主要有豆荚螟、柠条豆象和柠条种子小蜂3种。为了探明不同种植模式对柠条种实害虫种群危害的影响,2022年在宁夏灵武白芨滩国家级自然保护区内选择3种种植模式下的柠条林,采用随机抽样调查法研究了3种种实害虫的危害状况。结果表明,不同种植模式下种实害虫对柠条的危害率存在差异,其中:以密集种植模式下豆荚危害率最高,其他2种种植模式相对较低;以散生种植模式下豆粒危害率最低,其他2种种植模式之间相差不大。在不同种植模式下,均以豆荚螟对豆粒的危害最严重,其中散生种植模式下豆粒危害率最低,显著低于条带化种植模式和密集种植模式;而在不同种植模式之间,柠条种子小蜂和柠条豆象的豆粒危害率均差异不显著。说明种植模式影响柠条种实害虫的发生,斑块化密集种植模式下种实害虫的危害最严重,而与其他沙生植物混合散生种植模式下种实害虫的危害最轻。

基于HPLC指纹图谱和多组分含量测定结合化学模式识别研究的龙眼核质量评价

目的 建立龙眼Dimocarpus longan Lour.核HPLC指纹图谱及含量测定方法。方法 建立13批龙眼核指纹图谱,结合指纹图谱相似度评价及化学模式识别研究对龙眼核质量进行分析,并测定其中没食子酸、柯里拉京、鞣花酸的含量。结果 13批龙眼核样品相似度在0.919~0.999,标定共有峰11个,并指认出3种成分;聚类分析(HCA)将13批龙眼核聚为3类,主成分分析(PCA)提取到3个主成分,正交偏最小二乘判别分析(OPLS-DA)筛选出5个差异性成分;定量分析得到13批龙眼核中没食子酸、柯里拉京金、鞣花酸的含量范围依次为0.65~1.8 mg·g^(-1)、3.02~5.46 mg·g^(-1)、3.18~4.49 mg·g^(-1)。结论 建立的HPLC指纹图谱及含量测定方法重复性、稳定性良好,能够为龙眼核质量评价提供参考。

海甘蓝发育种子中FAE1的表达模式与芥酸积累

为了探究海甘蓝控制超长链脂肪酸合成的关键基因FAE1的表达模式及其对发育种子中芥酸合成的影响,针对已克隆的5个FAE1同源基因(CaFAE1-1~CaFAE1-5),以苗期根、茎、叶及不同发育时期(花后5~25 d)的种子为材料,采用实时荧光定量PCR(qRT-PCR)技术分析其表达模式;并采用气相质谱技术(GC-MS)检测不同发育时期种子中的脂肪酸相对含量,重点探讨不同CaFAE1基因表达量与种子芥酸含量的相关性。结果表明,相对种子而言,5个CaFAE1基因在根、茎、叶组织中的表达水平极低;而在花后5~25 d种子中,CaFAE1-3的表达量均为最高,且随种子发育进程呈逐渐升高趋势;其他4个CaFAE1基因的表达量均呈先升后降趋势,均于花后20 d达到最高值,随后CaFAE1-5和CaFAE1-4表达量迅速下降。GC-MS分析结果表明,花后5~15 d种子中,长链饱和脂肪酸C16∶0和C18∶0及单不饱和脂肪酸C18∶1相对含量均显著高于超长链脂肪酸含量,随后其含量快速下降,表明CaFAE1以C18∶0和C18∶1为底物的脂肪酸碳链延长主要发生在花后15 d及以后,且终产物主要为C22∶0和C22∶1。CaFAE1基因表达量与脂肪酸组分含量相关性分析结果表明,在花后5~25 d种子中,5个CaFAE1的表达量均与超长链脂肪酸含量呈正相关,且CaFAE1-1、CaFAE1-2和CaFAE1-3与芥酸相对含量呈显著或极显著正相关。由此推测,多拷贝、高活性FAE1的高水平表达可能是海甘蓝种子中芥酸含量高的主要成因。

Effects of temperature and light on seed germination of ephemeral plants in the Gurbantunggut Desert, China: implications for vegetation restoration

Seed germination is a key transitional stage in plant life cycle and is strongly regulated by temperature and light.Therefore, research on the effects of temperature and light on seed germination is extremely meaningful for vegetation restoration, especially in desert ecosystems.Seeds of 28 ephemeral plants collected from the Gurbantunggut Desert of China were incubated at different temperatures(5℃/1℃, 15℃/5℃, 20℃/5℃, 25℃/10℃ and 30℃/15℃) in 12-h light/12-h darkness or continuous darkness regimes, and the responses of seed germination to temperature and light and the germination speed were studied in 2016.Results showed that seed germination percentage of the 28 ephemeral plants significantly differed to temperature and light.We classified the studied plants as the following groups based on their responses to temperature: 1 low temperature responsed plants, 12 moderate temperature responsed plants, 7 high temperature responsed plants, 4 non-responsed plants and 5 plants of no germination.It should be noted that Corispermum lehmannianum Bunge is sensitive to both moderate and high temperatures.There were 4 groups of plant in response to light, i.e., 7 light responsed plants, 10 dark responsed plants, 6 light non-responsed plants and 5 plants of no germination.Based on seed germination speed of the 28 ephemeral plants, we divided them into 4 patterns of germination, i.e., very rapid, moderately rapid, moderate and slow.Combining variations of temperature, precipitation and sand dune types in the study area, we suggested that very rapid and moderately rapid germinated plants could be used to moving sand dunes in early spring during vegetation restoration, moderate germinated plants could be used to semi-fixed sand dunes in late autumn, and slow germinated plants could be used to sand plain in summer.Thus, seedling establishment and vegetation restoration would be improved by considering seed germination characteristics of these ephemeral plants in the Gurbantunggut Desert, China.

油菜“宽垄间距-垄作垄收”机械化生产试验研究

为研究“普通平作”模式与“宽垄间距-垄作垄收”模式对油菜主要农艺性状及产量性状的影响,为探究油菜机械化生产的最佳种植模式提供技术参考,以重庆市农业科学院水稻研究所提供的庆油3号为材料,测定“普通平作”与“宽垄间距-垄作垄收”两种种植模式下油菜机械化生产的主要农艺性状及产量性状,并比较两种种植模式的经济效益。结果表明:“普通平作”模式虽然单位面积有效株数多于“宽垄间距-垄作垄收”模式,但“宽垄间距-垄作垄收”模式种植的油菜产量性状更优,损失量和损失率更低,经济效益更高,更适合机械化收获。两种种植模式的主要农艺性状差别不大,但单位面积产量与经济效益存在明显差异,选择适宜的农机农艺融合模式进行机械化生产可获得高产高效。

Single-seed sowing increased pod yield at a reduced seeding rate by improving root physiological state of Arachis hypogaea

Double-seed sowing(two seeds per hole)is the dominant pattern of peanut sowing in China,but within-hole plant competition usually limits their growth and yield formation.Besides,the traditional double-seed sowing method does not facilitate mechanization during sowing.The objective of this study was to determine if single-seed sowing at a proper seeding rate yielded better than traditional double-seed sowing pattern and the differences of physiological metabolism of roots.A field experiment was conducted in two consecutive years to compare pod yields of single-seed sowing at 180000(S180),225000(S225),and 270000 seeds ha^-1(S270)with that of double-seed sowing at 270000 seeds ha^-1(D270)using a completely randomized block design with four replications.And the root bleeding sap rate,nutrient content,and the main hormone contents in root bleeding sap were also comparatively investigated.Although the pod yields of single-seed sowing at the three densities were higher than that of traditional double-seed sowing(D270),S225 yielded better than the other two single-seed sowing treatments(S180 and S270).The increased pod yield in single-seed sowing at 225000 seeds ha^-1 was mainly due to the higher pod dry weight per plant and harvest index.The improved pod dry weight and shoot growth had closely relationship with the enhanced root physiological traits such as the increased root bleeding sap rate,content of free amino acids,soluble sugars,K^+,Mg^2+,Zn^2+,and Ca^2+of the individual plant root.The improved activity of root reductive,nitrate reductase(NR)and ATPase and higher zeatin and zeatin riboside(Z+ZR)content of root bleeding sap were alsocrucial to the pod and shoot growth of peanut.Single-seed sowing at a moderate seeding rate(S225)is a potential practice to increase pod yield and to save seed cost.

新发展格局下实现种业科技自立自强的瓶颈及其破解

新发展格局下实现种业科技自立自强是破解“卡脖子”难题、打好种业翻身仗的重要战略部署。构建新发展格局下的种业“双循环”体系是保障国家粮食及重要农产品源头安全的重要手段。当前,实现我国种业科技自立自强仍存在国内发展动力不足与国际竞争压力并存的“双重瓶颈”,主要表现为种业源头存在“风险点”,种业研发体系存在“卡点”,种业公众认知存在“盲点”,种业政策存在“薄弱点”以及种业双循环贸易存在“隐患点”等五个方面。因此,新发展格局下要实现我国种业科技自立自强,必须夯实种业科技创新基础、完善种业研发体系、改善公众风险认知情况、建立完善的种业保障机制、健全种业市场保障措施。

General Survey of Soil Seed Bank in China

Soil seed bank refers to the sum of upper litter decay and all survival seeds in the soil. It plays a unique role in restoring the surface vegetation and protecting biodiversity. Chinese scholars have carried out extensive researches on the soil seed bank,and have obtained considerable achievements. On the basis of reading extensive literature,this paper summarized the current research results and found that the research contents of soil seed bank in China mainly involve the following aspects:( i) research method of soil seed bank;( ii) classification system of soil seed bank;( iii) spatial pattern of soil seed bank;( iv) relationship between soil seed bank and surface vegetation;( v) dynamic characteristic and seedling replanting of soil seed bank;( vi) application of soil seed bank in vegetation restoration. On the basis of the above summary,it came up with existing problems and future research direction of China's soil seed bank from system construction,field observation,disciplinary combination,interference factors,and community succession.

Influence of nitrogen impurities on the characteristics of a patterned helium dielectric barrier discharge at atmospheric pressure

In this paper, a two-dimensional axisymmetric fluid model was established to investigate the influence of nitrogen impurity content on the discharge pattern and the relevant discharge characteristics in an atmosphere pressure helium dielectric barrier discharge(DBD). The results indicated that when the nitrogen content was increased from 1 to 100 ppm, the discharge pattern evolved from a concentric-ring pattern into a uniform pattern, and then returned to the concentricring pattern. In this process, the discharge mode at the current peak moment transformed from glow mode into Townsend mode, and then returned to glow mode. Further analyses revealed that with the increase of impurity level, the rate of Penning ionization at the pre-ionization stage increased at first and decreased afterwards, resulting in a similar evolution pattern of seed electron level. This evolution trend was believed to be resulted from the competition between the N2 partial pressure and the consumption rate of metastable species. Moreover, the discharge uniformity was found positively correlated with the spatial uniformity of seed electron density as well as the seed electron level. The reason for this correlation was explained by the reduction of radial electric field strength and the promotion of seed electron uniformity as pre-ionization level increases. The results obtained in this work may help better understand the pattern formation mechanism of atmospheric helium DBD under the variation of N2 impurity level, thereby providing a possible means of regulating the discharge performance in practical application scenarios.

水气热耦合作用下寒区稻种吸水规律试验研究

实施水气热耦合供给的新型浸种催芽模式已开始在水稻种植中实践和推广。稻种萌发过程中,水分、氧气和温度的相互作用关系尚未完全摸清。选择增氧时距和温度为控制参数,对绥粳27稻种吸水规律开展全因素试验分析。结果表明,稻种吸水速度主要受温度影响,受氧气状态影响不明显。稻种吸水速度随温度升高而增加,可通过调节温度的方式缩短浸种耗时。

不同种源文冠果种实性状差异及优良单株筛选

为探究文冠果在不同种源间的种实性状差异,筛选出产量较高的优良单株,对4个地区(新疆昌吉、内蒙古翁牛特旗、宁夏银川和河北张家口)引种至山东的121株文冠果单株的15个种实性状进行分析,并分析性状间的相关性,结合主成分分析、模糊隶属函数法及多维空间坐标向量综合评定值累加法筛选优良单株。结果表明:参试单株种源间单果鲜重、单果种子重和种仁百粒重的变异系数(CV)较大,分别为28.53%、22.41%和21.34%;种仁含油率的CV较小,为7.75%。各种源单株种实性状中,宁夏银川单株种子产量表现显著,其余种源不显著;4个种源其余性状均有显著或极显著差异。单株种子产量和单果鲜重随种子纵径、种子横径的增大而增加;种子百粒重和种仁百粒重随单果鲜重、果实纵径的增大而增加;种子出仁率随种皮厚度的增大而降低;种仁含油率随单果种子数的增加而升高。15个种实性状构成4个主成分,分别为产量因子、种子出仁率、产油因子和果实出种率,4个主成分代表了15个种实性状信息总量的81.409%。利用主成分分析选择高产高油型优株,新疆昌吉的32、35号(CJ-32、CJ-35),内蒙古翁牛特旗的455号(WQ-455),宁夏银川的464号(YC-464)以及河北张家口的314、319号(ZJK-314、ZJK-319)排名前十;结合3种方法选择复合型优株,结果均比较接近。

全球种子:贸易格局与国际竞争力评价

从贸易规模、贸易对象、贸易价格和市场结构等方面,分析2021年新种子法修订后种子贸易格局,运用国际市场占有率、贸易竞争力和出口价格指数等评价种子国际竞争力,并探讨种子贸易格局与国际竞争力之间的关系。研究发现,全球大田作物类种子贸易呈逆差,少数国家粮食安全问题严峻;花卉类种子贸易互补性较强;蔬菜类种子出口国的龙头种企发挥主导作用。中国农作物种子进口市场结构趋于垄断化,而种子出口市场寡占、竞争和分散三种态势并存。进一步研究发现,与世界主要国家相比,中国种子国际竞争力较弱,并受诸多因素影响,其中外生因素包括技术性贸易措施、税收制度、贸易规则等,内生因素包括农作物种子的品质性状、种粮比效益等。因此,为促进中国农作物种业国际化发展以及种子更好地“引进来”和“走出去”,应建立健全检疫监管体系、推动种子进口来源多元化、加强良种培育科技创新、监测管控种子进口价格以及鼓励跨国育种、海外制种等。

工业控制系统终端渗透测试应用研究

随着工业互联网的发展,设备终端自身的安全问题越来越突出.如何对工业控制系统终端进行有效的安全测试已成为亟待研究和解决的关键问题.依据渗透测试流程,以输入验证错误漏洞渗透为例,研究工业控制系统终端的渗透测试应用方法.该方法从信息收集和渗透工具入手,对系统输入验证进行深入了解.在漏洞挖掘阶段,提出利用敏感测试输入对该漏洞的形式进行建模,并设计适用于工控程序的种子变异模式.该方法能够有效检测工控系统终端的输入验证错误漏洞,并发现大多数工控系统终端都存在同样的问题.实验中同时发现了由输入验证漏洞所产生的数据篡改、拒绝服务、权限获取和恶意脚本注入等安全威胁.最后为工控系统终端安全保护和设备防护提供了安全防护建议.

云贵高原区青贮玉米不同播种方式的饲草产量和效益

以大田生产试验数据为依据,分析了不同播种方案对青贮玉米单株生长、饲草产量和经济效益的影响。研究结果表明:云贵高原区青贮玉米生产时,采用农机穴播,播种量45kg/hm^(2),种植密度8~9万株/hm^(2)时,饲草产量和效益最高。与籽实玉米生产相比,青贮玉米不仅有更高的经济效益,而且在抵制自然灾害导致的减产风险方面也具有一定优势。但青贮玉米生产在收贮、运输及利用等方面与籽实玉米生产相比存在一定局限性。云贵高原区玉米改籽实为青贮原料生产时,其规模应与当地养牛、养羊业的发展规模相适应。

新发展格局下种业发展国际经验及对中国的启示

种子被称为农业的“芯片”,是粮食系统的基础元素,是保障“米袋子”和“菜篮子”的前提。本文通过对美国、德国及日本3个国际种业强国的优秀经验进行对比总结,发现各国均非常注重种子科研及成果转化、强调政府与市场多方主体合作、挖掘国内外优质种源。中国与国际种业强国之间的差距表现为:集中化程度不高、多元化竞争不足、国际市场竞争力不强等。基于此,在新发展格局下,本文为确保中国种业安全提出以下建议:粮食作物育种创新保障种子供给安全,非粮食作物育种创新驱动种子多元发展,“卡脖子”种子育种突破保障种子主权安全。

全球葵花籽油贸易演变格局及政策启示

基于社会网络分析法,使用2000-2020年的全球葵花籽油贸易数据,构建世界葵花籽油贸易的整体网络,分析全球葵花籽油贸易的演变特征及对中国葵花籽油贸易的政策启示。研究发现:2000-2020年全球葵花籽油贸易整体网络密度和互惠性分别提升了2.1%和4.4%,贸易伙伴国间的直接交易路径逐年缩短,整体网络联系愈发紧密;俄罗斯、德国、荷兰、比利时和土耳其保持着全球葵花籽油贸易核心国地位,乌克兰和中国的贸易地位不断提升;中国葵花籽油进口规模近十年来快速增长,贸易逆差不断扩大,面临较大贸易风险。据此建议,应着手提升我国在葵花籽油国际贸易中的协调控制能力,发挥在全球葵花籽油贸易市场中的枢纽作用,一方面深化同俄罗斯、乌克兰等核心国的合作,另一方面主动拓展朋友圈,增加从土耳其、阿根廷等其他出口国的进口,打造更为多元高效的葵花籽油贸易网络。