甘蓝新品种宁甘1号选育报告

宁甘1号是宁夏西吉县种子繁育管理站从当地农家品种变异单株中采用单株自交选育而成.在宁南山区区域试验中,平均折合产量178 488.75 kg/hm2,较对照品种晚丰增产23.4%.该品种株高40 cm,株幅110 cm,莲座叶12片;叶球高26.5 cm、叶球直径45 cm、叶球重8～12 kg,生育期175 d左右,属大平头晚熟甘蓝品种,抗寒、抗涝、抗病性强.适宜黄土高原冷凉区水地种植.     

苹果渣发酵饲料蛋白质含量的影响因素研究

研究了接种微生物、加入无机氮素和混菌发酵对苹果渣发酵产物蛋白质含量和得率的影响。结果表明:1向苹果渣中接入微生物进行固态发酵,可显著提高发酵产物的蛋白质含量。单菌Y12(无N处理)和单菌Y*6(加N处理)发酵产物蛋白质含量较无菌对照分别提高71.6%和143.9%;2加入无机氮素可显著提高发酵产物的蛋白质含量,加N处理纯蛋白质含量较无氮对照提高2.7%～161.8%;3采用混菌发酵(酵母菌与霉菌)可显著提高发酵产物的蛋白质含量,无N处理Y12+UA8,Y8+UA8和加N处理Y12+UA8,Y2+UA8的蛋白质含量,较相应酵母菌单菌发酵分别提高8.8%,4.8%和67.4%,28.9%;4加入无机氮可显著提高发酵产物的得率;加入无机氮可使单菌Y12和Y2发酵产物得率分别提高49.0%和22.3%,使Y12+UA8和Y2+UA8处理的发酵产物得率分别提高31.6%和22.4%。     

转盘式投苗机构的设计与调整

吊篮式移栽机是铺膜移栽机械中栽植率较好的机械，但直接投苗不够方便安全，而且容易漏苗，大面积移栽棉花效率低。我们设计了一种简单可靠的投苗机构，它调整简单方便，能够较大的提高整机的工作效率，降低漏苗率。     

硒硫相互作用对烤烟产量及品质的影响

试验在盆载条件下进行,研究表明,硒和硫对烟草的生长发育和烟叶品质诸方面存在着相互作用。硒、硫对烟草生长的影响则随硒、硫处理浓度、土壤类型及烟草生育不同而变化,红壤上低硒（＜0．94～6．18μg Se/g）促进了前期烟草生长,高硫（150μgS/g）处理加强了低硒对烟草生长促进作用。黄褐土上施硒抑制烟草的前期生长,在低硒（P＜6．18μgS/g）处理下,施硫减弱了硒对烟草的抑制作用,硒、硫表现出明显的颉颃作用。硒、硫处理对成熟烟草生物量的影响与前期烟草不同。高硫的加入可以减轻红壤对成熟烟草物量的抑制作用。烟叶主要化学成分烟碱、总糖、蛋白质及钾含量不仅取决于硒浓度,而且取决于施硫量,适量的硒、硫（6．18μgS/g和75μgS/g）配合处理可以使烟叶具有较高的总糖、烟碱和硒含量及较低的蛋白质含量。     

水分胁迫下马铃薯试管苗的生理响应

利用PEG-6000模拟根际水分胁迫法,对马铃薯试管苗进行了水分胁迫处理,研究马铃薯不同品种在不同水分胁迫程度下的生理反应。结果表明,马铃薯试管苗体内丙二醛(MDA)含量、脯氨酸(Pro)含量、过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性与可溶性蛋白质含量在水分胁迫下发生了不同的变化。其中,在轻度水分胁迫(10%PEG)下各马铃薯品种可溶性蛋白含量均上升,脯氨酸大量积累,MDA含量急剧增加,POD、SOD、CAT活性上升;经重度水分胁迫(20%PEG)后,以上各指标变化趋势不一。马铃薯不同品种对水分胁迫的反应敏感程度不一致,这与其不同的抗旱能力有关。     

多源强降雨灾情可信度智能判别方法

真实的灾情信息是有效防范和减轻强降雨灾害损失的重要参考。本研究以过程降雨强度（R）为指标,构建1984-2020年河北省县级多源气象灾情与致灾过程相匹配的强降雨灾害事件库。经过人工质控,获得真实灾情信息2305组,伪灾情信息263组。采用相关分析法确定与灾害发生程度（灾度）显著相关的降雨关键特征因子,基于单类支持向量机和十折交叉检验法,随机抽取10次样本,建立强降雨灾情气象因子致灾判别模型,并进行检验优化,以探索智能化、易用性的多源强降雨灾情可信度智能判别方法。结果表明：（1）与灾度显著相关的降雨关键特征因子共计11个,分别为最大降雨量、最小降雨量、过程平均降雨量、日均降雨量、平均小时雨强、1h最大雨量、3h最大雨量、6h最大雨量、12h最大雨量、24h最大雨量及前10日降雨总量,均通过了0.01水平显著性检验。（2）采用11个因子建立10个致灾判别模型（M1-M10）,依据真实灾情判别准确率确定最优模型为M9,其证真率为96.4%,证伪率为67.6%,表明该模型对灾情真伪判定较为片面,应进一步优化。（3）通过自相关检验,以最大降雨量、平均小时雨强、1h最大雨量及前10日降雨总量4个因...     

暖季限时放牧对草地植被的影响

通过对三种不同时间的限时放牧与自由放牧条件下的草地植被群落特征、群落多样性及产草量之间比较研究表明:与自由放牧相比,限时放牧对草地植被有明显的影响,其中5h限时放牧区的草地植被高度、盖度、多度、多样性指数、均匀度指数、丰富度指数及产草量均高于6h限时放牧区、7h限时放牧区和自由放牧区.     

砂姜黑土区花生田种植前后土壤肥力空间变异特征分析及评价

为明确砂姜黑土区花生种植前和成熟期土壤肥力状况及空间变异特征,本研究利用地理信息系统(GIS)和地统计学技术,运用模糊隶属度函数法,对河南省正阳县砂姜黑土土壤肥力状况及其空间变异特征进行分析。结果表明,与种植前相比,花生成熟期土壤有效硫含量明显下降,有机质、全氮、速效钾、有效铁和有效锌含量均有不同程度的提高,其中土壤全氮和有效磷含量增幅较大,分别增加10.17%和16.37%,但有机质和有效锌含量仍处于较低水平。花生种植前和成熟期土壤pH值变异系数分别为6.18%和6.36%,属弱变异,其余土壤养分指标变异系数介于12.58%~44.94%之间,属中等变异。不同土壤肥力指标对土壤肥力综合指标(IFI)的贡献存在差异,其中有机质含量对土壤肥力的贡献最大。半方差分析结果表明,花生种植前IFI的空间相关性较强,变异函数以球状模型拟合效果最好,空间分布特征主要受自然因素影响;花生成熟期IFI的空间相关性中等,变异函数以高斯模型拟合效果最好,空间分布特征受自然因素和人为活动共同影响。正阳县IFI多集中在0.58~0.72之间,表明土壤肥力整体处于中等偏上水平。另外,花生种植前IFI低于花生成熟期,且IFI空间分布呈南高北低的特征。综合分析,在正阳县砂姜黑土区花生生产上,应适当减少氮磷用量,增加有机肥和锌肥的施用,尤其是其南部地区。本研究结果可为砂姜黑土区花生优质高产的合理施肥和培肥地力提供科学指导。     

Impacts of silver nanoparticles on enzymatic activities, nitrifying bacteria, and nitrogen transformation in soil amended with ammonium and nitrate

Silver nanoparticles (AgNPs) are effective antimicrobial compounds that are used in a myriad of applications. Soil microorganisms play crucial roles in nitrogen cycling, but there is a lack of comprehensive understanding of the effects of AgNPs on enzymatic activity in the nitrogen cycle, nitrifying bacteria, and nitrogen transformation in soil. Herein, enzyme activities were determined following the addition of different forms of nitrogen, ammonium nitrogen ((NH₄)₂SO₄), nitrate nitrogen (KNO₃), and amide nitrogen (urea, CO(NH₂)₂) at 200 mg N kg^-1, into the soil amended with AgNPs at 0, 10, 50, and 100 mg kg^-1. After 7 d of incubation with 10 mg kg^-1 AgNPs, the activities of urease, nitrite reductase (NiR), nitrate reductase (NaR), and hydroxylamine reductase (HyR) were reduced by 12.5%, 25.0%, 12.2%, and 24.2%, respectively. Of particular note, more than 53.5%, 61.7%, and 34.7% of NaR, NiR, and HyR activities, respectively, were inhibited at 100 mg kg^-1AgNPs. The abundance (most probable number) of ammonia- and nitrite-oxidizing bacteria (AOB and NOB, respectively) was measured using real-time quantitative polymerase chain reaction (qPCR) and the Cochran method. The abundance of AOB and NOB decreased when AgNPs were present in the soil. The NH₄NO₃ amendment increased copy numbers of bacterial and archaeal amoA nitrification functional genes, by 38.3% and 12.4%, respectively, but AgNPs at 50 mg kg^-1 decreased these values by 70% and 56.4%, respectively. The results of ¹⁵N enrichment (atom% excess) of NH₄⁺ and NO₃^- experiments illustrated the influence of AgNPs on soil nitrogen transformation. According to the ¹⁵N atom% excess detected, the conversion of ¹⁵N-labeled NH₄⁺ to NO₃^- was significantly inhibited by the different levels of AgNPs in soil. The reduced gross nitrification rate further confirmed this finding. Overall, this study revealed considerable evidence that AgNPs inhibited nitrogen cycle enzyme activity, the number of nitrifying bacteria, the abundance of the amoA gene, and the gross nitrification rate. Silver nanoparticles inhibited nitrogen transformation, and the rate of nitrification was also negatively correlated with AgNP levels.     

Studies into the possible protozoan aetiology of swimbladder inflammation in carp fry

Abstract. Laboratory examinations of pond-reared common carp, Cyprinus carpio L., revealed a close correlation between the prevalence of swimbladder inflammation (SBI), renal sphaerosporosis and infection by C-blood-protozoan among the carp fry. In impression smears as well as light and electron microscopic preparations we detected developmental stages of intercellular protozoa, mainly in the loose fibrous tissue of the swimbladder. The parasites multiplied by internal budding so that 20–46 secondary cells were formed in each primary cell and two tertiary cells were formed in each secondary cell. The final stage of development was a unit consisting of a secondary cell enclosing two tertiary cells, i.e. a so-called triple formation, which bore a close resemblance to the early sporogonic stages of the renal sphaerosporan Sphaerospora angulata Fujita, 1912. Certain morphological similarities and the frequent simultaneous presence of the swimbladder protozoan, C-bloodprotozoan, and S. angulata in hosts with clinical SBI have led us to postulate that the former two parasites could represent the hitherto unknown presporogonic stages of S. angulata. In view of the pathological changes caused by the parasites in the hosts with clinical SBI, and negative bacteriological and virological findings we have postulated that the swimbladder protozoan is the primary cause of SBI in carp fry.