强化型EM菌剂对金针菇菌糠堆肥的影响

为提高EM菌剂在菌糠堆肥中的应用效果,加速腐熟进程,改善堆肥质量,采用纤维素酶与木聚糖酶高产菌株黑曲霉SNH-7、蛋白酶高产菌株枯草芽孢杆菌SNK-103与EM菌剂进行复配,研制强化型EM菌剂,并研究其对菌糠堆肥的影响。结果表明：与普通EM菌剂相比,接种强化型EM菌剂的处理堆肥过程中微生物代谢更加旺盛,温度、pH、EC值、总有机碳、可溶性有机碳、总氮、铵态氮、硝态氮、C/N、腐植酸和黄腐酸含量等理化指标的升高或降低幅度更大,腐熟进程加快;成品堆肥的GI提高,C/N降低,总氮、硝态氮、总腐植酸和游离腐植酸的含量升高,生物安全性更好、肥效更高。说明在EM菌剂中补充纤维素酶、木聚糖酶和蛋白酶高产菌株,可强化其对纤维素、木质素和蛋白质的降解能力,在无辅料、高C/N、低pH的不利条件下,添加该菌剂能加速堆肥进程,提高堆肥质量。     

Genome wide association studies (GWAS) of element contents in grain with a special focus on zinc and iron in a world collection of barley (Hordeum vulgare L.)

Genome wide association studies (GWAS) were carried out to map Quantitative Trait Loci (QTL) associated with element contents in the grain using 336 spring barley. Of the elements analyzed, Fe content ranged from 21.9 to 91.0 mg kg⁻¹, Zn from 10.4 to 54.5 mg kg⁻¹, Ba from 0.2 to 8.9, Ca from 186.4 to 977.5, Cu from 1.5 to 9.8, K from 353.2 to 7721.5, Mg from 1049.8 to 2024.2, Mn from 8.1 to 22.9, Na from 55.9 to 627.9, P from 2272.9 to 5428.8, S from 880.7 to 1898.0, Si from 19.1 to 663.2, and Sr from 0.35 to 2.62 mg kg⁻¹. GWAS were carried out using 6519 SNP markers and multiple elements in MLM:PCA + K model in TASSEL software. Population analyses showed two sub-populations, primarily based on row types. GWAS for row types showed association with INTERMEDIUM-C, a modifier gene for lateral spikelet fertility in the 4H chromosome, validating current GWAS approach. GWAS also showed that 2 QTL for Ba, 2 for Ca, 4 for Cu, 11 for Fe, 2 for K, 3 for Mg, 6 for Mn, 4 for Na, 3 for S, 5 for Si, and 3 for Zn were mapped in barley chromosomes. The QTL identified in the current study are valuable for breeding nutrient dense barley cultivars in the future, especially Zn and Fe.     

耕作方式及秸秆还田对土壤性质、微生物碳源代谢及小麦产量的影响

以小麦品种济麦22为试验材料,采用裂区试验设计,耕作方式为主区,分别设常规翻耕(C)、深松(S)、旋耕(R)处理,副区为秸秆还田量,分别设秸秆全还田(P)和秸秆不还田(A)处理,采用Biolog Eco技术测定土壤微生物碳源代谢功能,并分析土壤基本理化性质和作物产量。结果显示:深松与秸秆还田均有利于土壤含水量和有机碳含量的提高,0～15 cm土层分别提高了9.78%和24.00%,15～30 cm土层分别提高了7.08%和15.81%;深松提高了15～30 cm土层的pH值6.67%,秸秆还田提高了0～15 cm土层的pH值4.32%。深松和秸秆还田均有利于代谢多样性(丰富度指数、香浓多样性指数)、碳源代谢强度的提高,0～15 cm土层分别提高了26.84%、3.84%和38.02%,15～30 cm土层分别提高了11.87%、 3.63%和14.74%。主成分分析表明常规翻耕秸秆不还田和旋耕耕作秸秆不还田碳源代谢功能相近,15～30 cm层次内常规翻耕秸秆全还田碳源代谢功能和深松耕作秸秆全还田处理相近。深松和秸秆还田平均提高了小麦产量5.82%,微生物碳源代谢功能与小麦产量具有极显著的相关性。     

大花君子兰叶绿体基因组及其特征

采用Illumina MiSeq测序平台对大花君子兰（Clivia miniata）叶片总DNA进行测序，通过组装获得了其叶绿体基因组（cpDNA）全长序列（158 114 bp）。对其cpDNA注释得到135个基因，包含87个蛋白编码基因、40个tRNA基因和8个rRNA基因。采用生物信息学方法对获得的cpDNA进行简单序列重复（SSR）分析和密码子偏好性分析。结果显示：①大花君子兰cpDNA中共有61个SSR位点，其中单核苷酸、二核苷酸、三核苷酸、四核苷酸、五核苷酸和六核苷酸重复数分别为38、9、2、8、3和1个，多数SSR分布在基因间隔区；②大花君子兰cpDNA密码子偏爱以A或U（T）结尾，亮氨酸使用频率最高，半胱氨酸使用频率最低。基于24种植物的cpDNA全长和23种植物的叶绿体ycf2基因序列进行系统发育分析，结果显示大花君子兰与石蒜科植物在同一分支，显示最近的亲缘关系，支持大花君子兰属于石蒜科。基于叶绿体ycf2的系统发育分析结果与基于cpDNA全长的系统发育分析研究结果大部分相同，支持ycf2基因可以代替cpDNA全长用于植物系统发育分析。     

Comparison of the microbial communities of alpacas and sheep fed diets with three different ratios of corn stalk to concentrate

The objective of this study was to investigate the characteristics of ruminal microbial communities of alpacas (Lama pacos) and sheep (Ovis aries) fed three diets with varying ratios of roughage (corn stalk) to concentrate, 3:7 (LS), 5:5 (MS) and 7:3 (HS). Six alpacas (one-year-old and weighing 29.5 ± 7.1 kg) and six sheep (one-year-old and weighing 27.9 ± 2.7 kg) were used in this study, in a replicated 3 × 3 Latin square experiment. Total protozoa concentration was determined under the microscope; total fungi and methanogens were assessed using quantitative polymerase chain reaction and expressed as a percentage of total bacterial 16S rRNA gene copies; bacterial communities were investigated by targeted 16S rRNA gene (V3–V4 region) sequencing. The percentage of fungi was significantly higher in alpacas than in sheep under the LS diet, while the concentration of protozoa was significantly lower in alpacas under HS, MS and LS diets. The alpha diversity including Shannon, Chao l and ACE indices of bacterial communities was higher in alpacas than in sheep, under the LS diet. A total of 299 genera belonging to 22 phyla were observed in the forestomach of alpaca and sheep, with Bacteroidetes and Firmicutes dominating both animal species. Phyla Armatimonadetes and Fusobacteria, as well as 64 genera, were detected only in alpacas, whereas phyla Acidobacteria and Nitrospira, as well as 44 genera, were found only in sheep. The abundance of cellulolytic bacteria, including Butyrivibrio and Pseudobutyrivibrio, was higher in alpacas than in sheep under all three diets. These differences in the forestomach microbial communities partly explained why alpacas displayed a higher poor-quality roughage digestibility, and a lower methane production. Results also revealed that the adverse effects of high-concentrate diets (70%) were lesser in alpacas than in sheep.     

叶轮出口边对双蜗壳泵压力脉动的影响

泵的叶轮扫掠蜗壳隔舌时产生的压力脉动是引起船用泵振动噪声的原因之一.为尽可能弱化这一影响,分别设计了叶片出口边与前后盖板基本面垂直和倾斜的2种不同形式叶轮,将其配置在相同的双蜗壳中,通过数值计算与样机试验相结合的手段,对蜗壳内9个不同位置的压力脉动情况进行对比分析.结果表明:出口边倾斜的叶轮相比于出口边垂直的叶轮可明显改善蜗壳内次脉动的“驼峰”现象,且可以进一步降低隔舌处主波动的压力峰值;对蜗壳内2个隔舌稍前的位置,出口边倾斜的叶轮反而会使得该点的压力系数幅值明显增大,且该点主波动的周期数发生改变;2种叶轮出口边的不同形式对蜗壳出口位置的压力脉动的影响基本相同;采用出口边倾斜叶轮对改善因叶轮与隔舌间的液流压力脉动是可行的.     

Effect of transferring lignocellulose-degrading bacteria from termite to rumen fluid of sheep on in vitro gas production,fermentation parameters,microbial populations and enzyme activity

The digestive tract of termite(Microcerotermes diversus) contains a variety of lignocellulose-degrading bacteria with exocellulases enzyme activity, not found in the rumen, which could potentially improve fiber degradation in the rumen. The objectives of the current study were to determine the effect of inoculation of rumen fluid(RF) with three species of bacteria isolated from termite digestive tract, Bacillus licheniformis, Ochrobactrum intermedium, and Microbacterium paludicola, on in vitro gas production(IVGP), fermentation parameters, nutrient disappearance, microbial populations, and hydrolytic enzyme activities with fibrous wheat straw(WS) and date leaf(DL) as incubation substrate. Inoculation of RF with either of three termite bacteria increased(P0.05) ammonia-N concentration compared with the control group(free of termite gut bacteria). Termite bacteria inoculation had no effect(P0.05) on gas production characteristics, dry matter, organic matter and neutral detergent fiber disappearance, pH, and concentration and composition of volatile fatty acids. Population of proteolytic bacteria and protozoa, but not cellulolytic bacteria, were increased(P0.05) when RF was inoculated with termite bacteria with both WS and DL substrates. Inoculation of RF with termite bacteria increased protease activity, while activities of carboxymethyl-cellulase, microcrystalline-cellulase, α-amylase and filter paper degrading activity remained unchanged(P0.05). Overall, the results of this study indicated that transferring lignocellulose-degrading bacteria, isolated from digestive tract of termite, to rumen liquid increased protozoa and proteolytic bacteria population and consequently increased protease activity and ammonia-N concentration in vitro, however, no effect on fermentation and fiber degradation parameters were detected. These results suggest that the termite bacteria might be rapidly lysed by the rumen microbes before beneficial effects on the rumen fermentation process could occur.     

减氮条件下密度对望两优361产量的影响

为探索减氮条件下密度对望两优361产量的影响,2018年在马庙镇进行了该试验。试验结果表明：怀宁县单季稻施肥量应为：N:P:K=13.5:5.4:10.8。在此施肥量的基础上： 1.5万穴/667m_²为最佳移栽密度。     

土壤养分位与广义氧化还原电极电势

 根据广义氧化还原理论,给出了土壤溶液中NH₄⁺,P,Ca等养料成份的广义氧化还原电极电势。与养分位比较,用广义氧化还原电极电势来量度土壤养分有效度具有较多的优越性。