凉山烟区气象因子与烤烟烟叶化学成分含量的关系

运用简单和典型相关分析方法,对凉山烟区主要气象因子与烟叶化学成分含量的关系进行了研究。结果表明,几个主要气象因子对烟叶化学成分含量的影响为:日均温空气相对湿度日照时数降水量气温日较差;旺长期的气象因子对化学成分含量影响最大;气象因子对还原糖、总糖、总植物碱和钾含量影响最大;烟叶总糖、还原糖、总植物碱的含量与伸根期气温、成熟期气温、旺长期日照时数、成熟期空气相对湿度呈正相关,与旺长期气温、旺长期空气相对湿度呈负相关;糖碱比与成熟期降水量呈正相关。统计还发现,在一定范围内,旺长期的温度和空气相对湿度降低,旺长期日照时数和成熟期降水增多能明显提高烟叶的含钾量。     

烟叶DNA甲基化特征与化学成分的相关性

为明确烟叶DNA甲基化的特征与化学成分的关系,利用烤烟DNA甲基化DArT芯片,分析了K326、红花大金元(红大)和遵烟6号在贵定和兴义两个试点,3个部位烟叶在不同发育时期的DNA甲基化特征和化学成分含量。结果显示,烤烟DNA甲基化水平变异较高,最高为64%,最低为35.4%,平均为47.61%,变幅为28.6%。品种间的甲基化模式差异最大,其次是生长部位。DNA甲基化水平与12种物质代谢关键酶活性和76种致香成分的相关分析发现,DNA甲基化与这些酶活性和化学成分呈极显著相关(p0.01),在3个品种中同步呈现极显著相关(p0.0001)的酶及化学成分有34个,不同品种中也呈现出受特异性调控的化学物质。     

八大香型风格新鲜烟叶代谢特征的生态成因分析

为考察生态因素对鲜烟叶代谢特征的影响,根据全国烤烟烟叶香型风格区划研究结果,按照八大香型风格,结合气象数据,分析了鲜烟叶特征代谢物(脂类化合物、含氮化合物、糖类化合物、有机酸类化合物、核酸类化合物、甾醇类化合物)与不同气象因子的相关性,并分析了各类代谢物的生态成因。结果表明,每个风格区的特征代谢物均与生态条件一定程度相关,温度、日照时数、降雨量等生态特征数据的变化可解释部分特征代谢产物的积累,表明鲜烟叶的代谢特征与环境生态条件紧密相关,其中与代谢物含量有较高相关性的气候因子为大田中后期温度和大田中后期日照时数。      

湘南典型浓香型烟叶产区烤烟大田生育期气候特征分析

为揭示与湘南典型浓香型烤烟风格特色密切相关的生态因子,采用湘南桂阳和江华烟区1981-2010年气象观测资料,以非线性多项式拟合回归方法分析湘南烟区烤烟生育期气候变化特征。研究结果表明:(1)桂阳和江华烟区烤烟伸根期气温均低于15℃,日照时数均在4 h以下,日降水量持续上升,表现出少光多雨,气温偏低的特点,其中移栽期和伸根期“低温寡照”是影响湘南典型浓香型烟叶风格特征的主要限制因子。(2)桂阳和江华烟区成熟期最高气温分别是29.27℃和28.35℃,日均光照时数6月下旬后持续增加,温差也随之增大,而降雨量逐渐减少,空气相对湿度逐渐降低,表现出多光少雨,气温偏高,相对湿度低的特点,其中成熟期“高温逼熟”是影响湘南典型浓香型烟叶风格特征的主要限制因子。湘南烟区成熟期的西南季风和地方焚风是影响浓香型烟叶风格特色彰显的气象因子之一。     

生态因子对贵州烟叶主要化学成分的影响

研究了生态因子（海拔、气象和土壤养分等）与烟叶化学成分的相关关系。结果表明,海拔增加,中、上部烟叶的总糖和氯含量增加,而烟碱含量降低。气象因子中,对烟叶化学成分影响最大的因素是6月份的日照时数、7月份的降水量和气温。土壤养分中,硝态氮含量与上部烟叶的烟碱、总氮、蛋白质含量呈正相关;速效钾含量与中、上部烟叶钾含量呈正相关。     

烤烟国家标准(40级)烟叶平衡含水率测定报告

本实验测定了烤烟国家标准(40级)烟叶在相同温度(25℃)、不同相对湿度(45%、65%、85%)条件下的平衡含水率,提供了一套有价值的各等级烟叶平衡含水率的工艺参数。其规律是:在相同温度下,同等级烟叶和烟梗的平衡含水率随相对湿度增加而增加,且烟梗的平衡含水率略高于烟叶;在相同温湿度条件下,中部烟叶的平衡含水率最高,上部次之,下部最低;同部位烟叶的平衡含水率以桔黄色最高,柠檬黄稍低;随着烟叶含青度的增加,平衡含水率明显降低;同部位烟叶的平衡含水率随等级的提高而增加;在温度为25℃、相对湿度为45%时,完熟组烟叶的平衡含水率最高,青黄组烟叶最低。     

基于丽江生态条件的KRK26烟叶工业可用性研究

为了探明丽江烟区与津巴布韦烟区气候相似性及所产KRK26烟叶工业可用性,采用数据调查、相关分析方法比较了丽江及我国其他代表性植烟区烤烟大田生育期气象因子(温度、日照时数和降雨量)与津巴布韦烟区气候相似性,同时选取了2104—2016年丽江产区KRK26中部烟叶90个样品,对其外观质量、内在化学成分及感官评吸质量进行系统分析。结果表明:(1)丽江烤烟大田生育期平均气温20.6℃,日照时数802.2 h,降雨量397.5 mm,气候条件适宜,适合烤烟种植。(2)丽江烟区与津巴布韦气候的欧式距离值为1.25,气候相似性高于云南省及国内KRK26代表性植烟区。(3)丽江KRK26烟叶外观质量较好,工业可用性较高,与津巴布韦烟叶内在化学成分夹角余弦值达到0.997,相似度极高,较好地符合中式卷烟风格特色需求。(4)丽江KRK26烟叶风格稳定,香韵种类丰富,在正甜香、木香、焦香、辛香香韵方面接近津巴布韦烟叶。     

恩施烟区气候周期性变化的特征分析

应用Morlet小波分析,研究了恩施烟区60年气候资料的周期性变化特征.结果表明,在月季尺度下,各气象因子只具有200 ～400 d的自然周期,但其周期强弱及时域分布特点不同；在年际尺度下,表现为多层次时间尺度结构特征,各气象因子普遍具有33年的主周期,部分具有19年的次周期和10年的小周期,说明该区域气候主要受太阳辐射周期变化影响,受ENSO循环影响不大.通过主周期变化规律可推断出未来约17年间恩施州降水量、气温、相对湿度、日照时数和平均风速可能会有下降趋势,该趋势有利于烟叶品质的提高,但对烟叶单产可能会有一定的影响.     

金神农烟区气候特征及其对烟叶品质的影响

对 “金神农”烟区近年来的气候特征进行了分析,并采用典型相关分析研究了2000-2013年气象条件对烟叶品质的影响。结果表明:(1)“金神农”烟区烟叶大田生长期热量条件和水分条件可以较好地满足优质烟叶生长需求。(2)气温和降雨量是影响“金神农”烟叶糖碱的主要因子,烟叶生长前期气温、大田期≥10 ℃积温的增加,烟叶进入旺长期后气温及各生育期降雨量的降低有利于金神农烟叶烟碱的合成和积累,而不利于总糖的积累。(3)烟叶感官质量与烟叶生长前期温度和各生育期日照时数正相关,而与烟株生长后期温度和成熟期降雨量负相关。     

焦甜香烟叶形成的气象因素分析

为了研究烤烟烟叶焦甜香香韵形成与气象因素之间的关系,以全国15个植烟区域的C3F为研究对象,运用相关、回归和判别分析对两者之间的关系进行了统计分析。结果表明,烤烟烟叶焦甜香香韵的形成与极端最高温、极端最低温、降水量、平均气温、日照时数、最大风速、最小相对湿度7个因素存在显著的回归关系,且对焦甜香风格形成的影响程度依次为：极端最高温>最小相对湿度>降水量>日照时数>平均气温>极端最低温>最大风速。以此7项指标建立的判别函数判别植烟区域焦甜香香韵的有无准确率较高。因此,在焦甜香烟叶生产过程中可以优化资源配置,适应以此7项指标为主的生态特点,为烟叶生产提供良好充分的适应条件。     

Short communication: Relationship of blood DNA methylation rate and milk performance in dairy cows

The objective of this study was to investigate the global methylation rate in blood DNA and its relationship with lactation performance. A total of 196 mid-lactation dairy cows were fed the same diet under the same management. Milk yield was recorded and blood samples were collected from the jugular vein before morning feeding. The blood global DNA methylation rates were quantified using a methylation quantification kit. Overall, the average blood global DNA methylation rate of all cows was 12.4%. When DNA methylation rates were compared between cows with high (n = 40; 37.0 to 42.0 kg/d) and low (n = 33; 24.0 to 30.0 kg/d) milk yield, DNA methylation rates in the lower-yield cows (14.1 ± 0.7%) were significantly higher than those in the higher-yield animals (11.6 ± 0.7%). Our results indicated an association of milk and protein yields with global DNA methylation rates in lactating dairy cows. However, further research is needed to determine whether this association reflects the true influence of epigenetic mechanisms on yield or whether other factors, such as different proportions of blood cell types in high- and low-yielding cows, affect apparent global DNA methylation levels.     

一种基于气象数据的仓储粮堆表层温度预测方法

智慧粮食最大的任务就是要确保粮食安全。粮仓储粮环境实时监测是粮食安全保障的重要技术。本研究针对气象因素对储粮环境的影响,建立了仓储粮堆温度参数和气象因素的数学关系,证明了基于气象数据进行粮堆温度预测的可行性。提出了基于气象8因素的储藏粮堆表层(粮面以下50 cm处)平均温度预测模型,利用气象的气温、气压、相对湿度、0 cm地面温度、日照时间、降水量、蒸发量、风速多个因素展开构建储藏粮堆表层平均温度估计。针对多元回归预测问题,提出了线性最小二乘回归和支持向量机(SVM)不同核函数回归的方法,设计了具体的建模算法。结果表明,仓储粮堆传感器获取的实际值与预测结果的趋势一致,均方根误差均小于5.3,证明了基于气象数据的仓储粮堆表层平均温度预测模型与方法的有效性,为加快实现智慧粮食提供了参考。     

Aberrant DNA methylation at imprinted genes in testicular sperm retrieved from men with obstructive azoospermia and undergoing vasectomy reversal

Male factor infertility has been associated with abnormal DNA methylation at imprinted genes. Little information is available on the status of imprinting in the sperm of men with azoospermia, including the association between aberrant imprinting and obstructive azoospermia (OA) or non-OA (NOA). Analysis of DNA methylation at imprinted genes in the sperm of men undergoing vasectomy reversal would aid determination of whether aberrant imprinting is associated with obstruction. Testicular sperm was retrieved from testicular biopsies obtained from men with azoospermia (N=18), including OA (N=10), NOA (N=5), and unknown pathology (N=3), and from men undergoing vasectomy reversal (N=17). Sperm was also obtained from proven fertile men (N=9). DNA methylation was investigated at multiple CpG sites within the differentially methylated regions (DMRs) of three imprinted genes, H19, IG-GTL2 and MEST, using bisulphite sequencing. Unique clones representative of single cells were analyzed. We found a significant decrease in DNA methylation at the H19 DMR in testicular sperm of azoospermic men compared with proven fertile men. The decrease was also significant between OA and proven fertile men, and between men undergoing vasectomy reversal and proven fertile men, suggesting that aberrant DNA methylation may be associated with obstruction. Changes in DNA methylation at IG-GTL2 and MEST DMRs among groups were not significant. Our data suggest that imprinting abnormalities may be associated with obstruction and may occur in response to changes in testicular environment and not only spermatogenesis failure, as previously reported. Methylation at the H19 DMR was particularly prone to modification in testicular sperm.     

烟草温光特性研究与利用：Ⅱ.气象因素对山东主栽烤烟品种生长发育及产质量的影响

为明确山东烟叶生产限制气象因子,优化气候资源配置,以主栽品种NC55、NC102和ZY100为材料,连续多年设置不同移栽期试验,研究气象因素与烟草生长发育和产量品质的关系。结果表明,移栽期对山东烟草农艺、经济性状有一定影响,对烟叶质量有显著影响;随移栽期推迟,部分试验叶宽增大,产量和产值表现先增后减趋势,大部分试验总植物碱含量显著下降,还原糖、总糖含量和糖碱比呈上升趋势,感官评吸质量呈现先升后降趋势。各气象因素与烟叶质量关联度顺序依次为日平均气温、日照时数、降水量。构建的基于温度的山东烟叶质量评价回归方程表明,NC55、NC102和ZY100在伸根期适宜平均气温分别为21.25~22.86 ℃、21.53~22.68 ℃、20.81~23.22 ℃,成熟后期适宜平均气温为23.67~24.54 ℃、24.32~24.83 ℃、22.03~24.42 ℃,结合山东省气温实际情况,NC55、NC102和ZY100适宜移栽期分别为5月5—19日、5月7—16日、5月1—25日。     

Characterization of methyl mercury in dental wastewater and correlation with sulfate-reducing bacterial DNA

Dental wastewater (DWW) was collected over two months from a 12-chair clinic and a single-chair office to identify conditions that may affect Hg methylation. DWW was settled for 24 h and samples were collected from the top and bottom of the supernatant to simulate a range of particles that may escape in-line traps. Total Hg spanned 5 orders of magnitude (0.02-5000 microM), following a log-normal distribution with p10, p50, and p90 concentration values of 0.24, 31 and 4000 microM, respectively; typically well in excess of free aqueous Hg solubility. Methyl Hg was present in high levels (2-270 nM), also following a log-normal distribution with p10, p50, and p90 concentration values of 2.8, 17, and 100 nM, respectively. There were no statistically significant differences (90% CI) in p50 methyl Hg or total Hg between the clinic and office. Methyl Hg was predicted from total Hg data by (+/- 95% CI): Log (Me-Hg) = 0.33 (+/- 0.06) x Log (T-Hg) - 2.27 (+/- 0.13). Total methyl Hg from DWW to U.S. wastewater collection systems is estimated to be 2-5 kg yr(-1). Equilibrium speciation modeling predicted that DWW Hg was primarily in sulfide-Hg complexes, except at high total Hg levels where organo-Hg complexes become significant. DNA extracts amplified by quantitative polymerase chain reaction with primers for total eubacteria and sulfate-reducing bacteria (SRB) indicated that the total eubacterial DNA was composed primarily of SRB, and highly significant correlations were found between methyl Hg and both amplified Desulfobacteraceae (p < 0.0001) and Desulfovibrionacaea DNA (p < 0.00001). Both are known Hg methylators. In marked contrast, there was no significant correlation between methyl Hg and amplified Desulfobulbus DNA, a genus generally not known to methylate Hg at high rates. These results strongly suggest that SRB are implicated in DWW Hg methylation.     

Blood as a surrogate marker for tissue-specific DNA methylation and changes due to folate depletion in post-partum female mice

Scope : DNA methylation patterns are tissue specific and may influence tissue‐specific gene regulation. Human studies investigating DNA methylation in relation to environmental factors primarily use blood‐derived DNA as a surrogate for DNA from target tissues. It is therefore important to know if DNA methylation changes in blood in response to environmental changes reflect those in target tissues. Folate intake can influence DNA methylation, via altered methyl donor supply. Previously, manipulations of maternal folate intake during pregnancy altered the patterns of DNA methylation in offspring but, to our knowledge, the consequences for maternal DNA methylation are unknown. Given the increased requirement for folate during pregnancy, mothers may be susceptible to aberrant DNA methylation due to folate depletion. Methods and results : Female mice were fed folate‐adequate (2 mg folic acid/kg diet) or folate‐deplete (0.4 mg folic acid/kg diet) diets prior to mating and during pregnancy and lactation. Following weaning, dams were killed and DNA methylation was assessed by pyrosequencing^® in blood, liver, and kidney at the Esr1, Igf2 differentially methylated region (DMR)1, Igf2 DMR2, Slc39a4CGI1, and Slc39a4CGI2 loci. We observed tissue‐specific differences in methylation at all loci. Folate depletion reduced Igf2 DMR1 and Slc39a4CGI1 methylation across all tissues and altered Igf2 DMR2 methylation in a tissue‐specific manner (p<0.05). Conclusion : Blood‐derived DNA methylation measurements may not always reflect methylation within other tissues. Further measurements of blood‐derived and tissue‐specific methylation patterns are warranted to understand the complexity of tissue‐specific responses to altered nutritional exposure.     

Coupling global methylation and gene expression profiles reveal key pathophysiological events in liver injury induced by a methyl-deficient diet

Scope : A methyl‐deficient diet induces liver injury similar to human nonalcoholic steatohepatitis, one of the main risk factors for the development of hepatocellular carcinoma. Previous studies have demonstrated that this diet perturbs DNA methylation by causing a profound loss of global cytosine methylation, predominantly at heavily methylated repetitive sequences. However, whether methyl deficiency affects the methylation status of gene promoters has not been explored. Methods and results : Mouse gene expression and CpG island microarrays were used to characterize the gene expression and CpG island methylation profiles in the livers of C57BL/6J mice fed a methyl‐deficient diet. We detected 164 genes that were differentially expressed and exhibited an inverse relationship between the gene expression and the extent of CpG island methylation. Furthermore, these genes were associated with altered lipid and glucose metabolism, DNA damage and repair, apoptosis, the development of fibrosis, and liver tissue remodeling. Although there were both increased and decreased levels of CpG island methylation, the number of hypomethylated genes was substantially greater than the number of hypermethylated genes. Conclusion : The results this study demonstrate that pairing methylation profiles with gene expression profiles is a powerful approach to identify dysregulated high‐priority fundamental pathophysiological pathways associated with disease development.     

Occurrence of Ochratoxin A in Chinese wines: influence of local meteorological parameters

A total of 119 wines, including 115 dry wines (77 red, 34 white, 4 rosé) and 4 ice wines, were obtained from four major regions around China (east, northeast, west, and northwest) from 1999 to 2009. Ochratoxin A (OTA) was detected by solid-phase extraction and high-performance liquid chromatography with fluorescence detection. The OTA levels ranged from <0.1 to 5.65 μg/L. The wines from the northeast area had the highest OTA level, with an average concentration of 2.18 μg/L. Analysis of the correlation between meteorological parameters and the OTA concentration in red wine revealed that the OTA concentration was positively correlated with rainfall in August, but negatively correlated with the average temperature. No significant correlation was found with the daily range of temperature and relative humidity. The results show that climate factors affect the OTA distribution in wines from the four major regions of China.