泾县2010年水稻施"汉枫"含硫肥料试验初报

于2010年在泾县良种场进行了水稻施＂汉枫＂含硫肥料试验。结果表明,在土壤有效硫含量较低的土壤上,施用＂汉枫＂含硫肥料对水稻有一定的增产效果,表现为有效穗和穗粒数上都有不同程度的提高,特别是对千粒重的影响较大。     

桃儿七不同外植体愈伤组织诱导研究

旨在建立一种桃儿七愈伤组织诱导培养体系,筛选出最佳诱导培养基和最适外植体。以MS为基本培养基,采用正交试验法研究6-BA、2,4-D和TDZ 3个因素及其组合对桃儿七成熟叶片、叶柄和茎段愈伤组织诱导率的影响。研究结果表明：3种外植体均可诱导出愈伤组织,叶片愈伤组织诱导率最高,达44.3%,其次是叶柄,达24.7%,茎的愈伤组织诱导率为18.1%,最佳愈伤组织诱导培养基为MS+ 6-BA 1.0 mg/L+TDZ 0.1 mg/L+2,4-D 1.5mg/L,细胞分裂素6-BA和TDZ联合使用有利于提高愈伤组织诱导率并改善愈伤组织质地。与茎段和叶片所得愈伤组织相比,以叶柄为外植体获得的愈伤组织质地较疏松,呈明显的黄绿色颗粒状,更适合进一步细胞培养和诱导分化。本研究建立了一种高效的桃儿七愈伤组织诱导培养体系,为桃儿七体细胞胚的培养提供了材料。     

干旱区人工绿洲规模的预测研究——以新疆叶尔羌河平原绿洲为例

规模适度的人工绿洲,是干旱区经济发展、社会稳定及生态环境向良性循环方向演化的基础。同时,人工绿洲规模又受水资源及其利用水平的严重制约。用系统动力学方法模拟特定区域内由人工绿洲、天然绿洲和水资源及其相关因子构成的复杂系统,并对模型运行结果进行回归分析,可建立合理的人工绿洲规模与水资源开发规模及利用水平之间的相关关系,进而对一定时期合理的人工绿洲规模进行预测。本文以叶尔羌河流域为例应用这一方法做了一点尝试。     

α-萘乙酸棉球扎顶对烤烟上部烟叶烟碱含量及糖碱比值的影响

以烤烟K326为供试品种,通过大田栽培试验,于烟株打顶后分别将不同浓度α-萘乙酸浸泡的棉球包扎于茎顶,用连续流动化学分析法测定了各处理所得上部烟叶橘黄二级(B2F)初烤烟的烟碱、总糖、还原糖等化学成分的含量,研究α-萘乙酸棉球扎顶对烤烟上部烟叶烟碱含量及糖碱比值的影响。结果表明:(1)在0～200mg/kg的浓度范围内,烤烟上部烟叶的总烟碱含量与α-萘乙酸的浓度呈负相关,而上部烟叶的水溶性总糖含量、还原糖含量及糖碱比值均与α-萘乙酸的浓度呈正相关;(2)打顶后用浓度为200mg/kg的α-萘乙酸溶液浸泡的棉球包扎烟株茎顶部,可较大幅度地降低烤烟上部烟叶的烟碱含量,并显著提高上部烟叶的糖碱比值,该处理所得B2F初烤烟的总烟碱含量从对照的5.9%下降至3.8%,而糖碱比值从对照的2.8上升至5.3,总烟碱含量和糖碱比值分别为对照的64.4%与189.3%;(3)打顶后用浓度为200mg/kg的α-萘乙酸棉球扎顶可显著提高烤烟上部烟叶的可用性。     

How the development of barren land into orchards affects soil ecosystem in Tibet, China

Fruit production is an important strategy for alleviating poverty on the Tibetan Plateau and leads to the conversion of natural barren land into orchards. This study aimed to understand how the conversion of barren land to peach (Prunus persica) orchards affects soil nutrients, heavy metals, and fungal communities in the 0-40 cm profile (at 20 cm intervals) in an experiment including three treatments, barren land (BL), peach orchards planting for 4 years (Y4), and peach orchards planting for 10 years (Y10). Results of the experiment showed that compared with BL, Y4 reduced the availability of some macronutrients (N and K) and micronutrients (Fe and Mn) due to the exclusive application of chemical fertilizer at the seedling stage. Conversely, Y10, which included six years of green cultivation management, using a combination of sheep manure and chemical fertilizer as well as alfalfa (Medicago sativa Linn) intercropping, effectively improved soil macronutrients, but did not enhance the availability of Fe and Mn. Although the investigated heavy metals (As, Hg, Pb, Cr, and Cd) in both the Y4 and Y10 soils were found to pose a low risk to food safety and soil environment, Hg, Cr, and As tended to accumulate in the subsoil (20-40 cm). Furthermore, the variations in the fungal community composition and functional groups were mainly driven by the interaction effects of macronutrients, micronutrients, and heavy metals, but their independent contribution to specific key functional groups cannot be overlooked. For example, Y4 and Y10 decreased the relative abundance of soil saprotrophic and lichenized fungi, mainly due to the loss of micronutrients (Fe and Mn). However, as a result of macronutrient input and dung saprotrophic fungi enrichment, orchard soils promoted the growth of pathogens that play critical roles in fungal co-occurrence networks. These findings indicate that supplementation with N or K fertilizer or manure at the seedling stage and fertilizers rich in Fe and Mn throughout the growth period would be beneficial to the balance of soil nutrients and provide insights into linking the variations in soil nutrients and heavy metals to the function of the fungal community during the conversion of barren land to orchards in alpine soil ecosystems. The risks posed by heavy metal accumulation and fungal pathogen enrichment should be actively prevented.     

Soil microbial respiration is regulated by stoichiometric imbalances: Evidence from a humidity gradient case

Humidity not only affects soil microbial respiration(SMR) directly, but, indirectly by regulating the availability of soil water and nutrients. However,the patterns of direct and indirect effects of humidity on SMR over large precipitation gradients remain unclear, limiting our understanding of the effects of precipitation changes on soil C cycle. Here, we investigated the relationships among humidity, soil nutrients, and SMR by identifying stoichiometric imbalances, microbial elemental homeosta...     

基于RF和MLR的土壤重金属影响因素分析及生物有效性预测

为探究影响土壤中重金属累积和生物有效性的因素,以桂北地区某铅锌矿流域为研究对象,综合运用单因子指数法、风险评价编码法(RAC)、多元线性回归模型(MLR)和随机森林模型(RF)进行土壤重金属(Pb、Zn、Cu和Cr)累积影响因素分析及生物有效性预测。结果表明：研究区Cr含量无超标且空间分布相对均匀(变异系数为0.51);Cu、Pb和Zn的含量均值(分别为52.58、280.31 mg·kg^-1和654.71 mg·kg^-1)均大于广西西江流域土壤重金属背景值,在思的河山前和地下河入口处全量和生物有效性均较大,对土壤生态环境具有一定风险;对于重金属全量分布和生物有效态的影响因素,阳离子交换量(CEC)、黏粒(Clay)、土壤有机质(SOM)和铁铝氧化物对Cr影响较大,SOM、Clay、pH和铁铝氧化物对Cu影响较大,pH、电导率(EC)和Clay对Pb影响较大,CEC、pH、土壤质地和铁铝氧化物对Zn影响较大;生物有效性预测结果显示RF和MLR均可较好地预测土壤重金属的全量与次生相,其中RF预测的R²区间为0.44～0.9...     

雕版印刷的茶叶广告

中国古代,散茶多用竹木、陶瓷乃至玉器所制茶盒做容器,而饼茶则多用绢纱之类包装。唐代诗人卢仝《走笔谢孟谏议寄新茶》中开篇的诗句：“口云谏议送书信,白绢斜封三道印”,说的就是用白绢包装饼茶。茶叶的绢纱包装上,有时会题写相关的诗句。唐武宗时的宰相李德裕作有《故人寄茶》诗,其中就提到四川老友寄送的新茶包装上有题诗：“剑外九华英,缄题下玉京。”这可能就是茶叶商标的雏形。另据研究者称,     

甘蓝型油菜胞质雄性不育育性恢复基因的分子标记

以甘蓝型油菜不育系212A和恢复系1521C组配的含144个单株的F2群体为试验材料,用RAPD和SRAP两种分子标记,结合BSA法,对可育DNA池与不育DNA池筛选,存在差异的引物再用分离群体进行检测。在690条RAPD引物、270对SRAP引物中,获得了与甘蓝型油菜恢复基因Rf连锁的1个RAPD标记OPS11-850和1个SRAP标记M17E13-150,标记与基因Rf之间的遗传距离分别为6.8 c M和10.8 c M。     

离子色谱法测定原料乳中硫氰酸钠的不确定度评定研究

建立了离子色谱法测定原料乳中硫氰酸钠结果不确定度评定的数学模型,对测量过程中的不确定度来源进行逐层分析和合成,运用最小二乘法对外标曲线拟合的不确定度进行了评定。在0．1mg／LM．0mg／L范围内,离子色谱法测定原料乳中硫氰酸钠含量,其相对扩展不确定度为0．02mg／L,k=2。该评定对采用外标法定量的离子色谱法测定结果的不确定度评定具有参考作用。