Effects of planting soybean in summer fallow on wheat grain yield,total N and Zn in grain and available N and Zn in soil on the Loess Plateau of China

Dryland wheat is the major contributor to wheat production in the world, where water deficiency and poor soil fertility are key factors limiting wheat grain yields and nutrient concentrations. A field experiment was carried out from June 2008 to June 2011 at Shilipu (latitude 35.12°N, longitude 107.45°E and altitude 1200 m above sea level) on the Loess Plateau (a typical dryland) in China, to investigate the effects of rotation with soybean (Glycine max) green manure (GM) on grain yield, total N and total Zn concentrations in subsequent wheat (Triticum aestivum L.), and on nitrate-N and available Zn in the soil. The benefits of crop rotation with soybean GM on wheat grain yields became more evident with time. In the second and third years, the grain yields of wheat rotated with soybean GM reached 4871 and 5089 kg ha⁻¹ at the 108 kg N ha⁻¹ rate. These yields were 21% and 12% higher than the highest yields of wheat under a fallow-winter wheat (FW) rotation. Rotation with soybean GM reduced the amount of N fertilizer required to obtain wheat grain yields and biomass levels similar to wheat grown in the FW rotation by 20–33%. In the first 2 years, average grain N concentrations over all N rates increased by 6% and 12%, and those of Zn increased by 26% and 14% under the soybean GM-winter wheat (SW) rotation, compared with the FW rotation. The increased grain N and Zn concentrations were found to be related to the increased concentrations of nitrate-N and available Zn in the soil, particularly at the sowing of winter wheat. However, grain N and Zn concentrations were not improved by rotation with soybean GM in the third year. This was attributed to the dilution effect caused by the more grain yield increase than its nutrient export. In conclusion, planting soybean for GM in fallow fields reduced the need for N fertilizer to enhance wheat yields in this dryland region. Change in wheat grain N and Zn concentrations was related to soil nutrient concentrations, and to the balance between increased grain yield and its nutrient export.     

A new cytotoxic sesquiterpene quinone produced by Penicillium sp. F00120 isolated from a deep sea sediment sample

A new fungal strain, displaying strong toxic activity against brine shrimp larvae, was isolated from a deep sea sediment sample collected at a depth of 1300 m. The strain, designated as F00120, was identified as a member of the genus Penicillium on the basis of morphology and ITS sequence analysis. One new sesquiterpene quinone, named penicilliumin A (1), along with two known compounds ergosterol (2) and ergosterol peroxide (3), were isolated and purified from the cultures of F00120 by silica gel column, Sephadex LH-20 column, and preparative thin layer chromatography. Their structures were elucidated by detailed nuclear magnetic resonance (NMR) and mass spectroscopic (MS) analysis as well as comparison with literature data. The new compound penicilliumin A inhibited in vitro proliferation of mouse melanoma (B16), human melanoma (A375), and human cervical carcinoma (Hela) cell lines moderately.     

Relationship between thermal anomalies in Tibetan Plateau and summer dust storm frequency over Tarim Basin,China

The dust storm is the most important and frequent meteorological disaster over Tarim Basin,which causes huge damages on local social economics.How to predict the springtime and summertime dust storm occurrence has become a hot issue for meteorologists.This paper employed the data of dust storm frequency and 10-m wind velocity at 35 stations over Tarim Basin and the reanalysis data from the National Center for Environmental Prediction and the National Center for Atmospheric Research(NCEP/NCAR) during 1961-2007 to study the relationship between dust storm frequency(DSF) in summer over Tarim Basin and the thermal anomalies in Tibetan Plateau in May by using the statistical methods,such as Empirical Orthogonal Function(EOF),correlation and binomial moving average.The results show when negative anomalies in Tibetan Plateau and positive anomalies in its southern region are present along 30°N(the second mode of surface temperature anomalies by EOF decomposition) in May,the time coefficient(PC2) plays an important role in summer DSF variation and has a close relation with the summer DSF at both inter-annual and decadal time scales.When negative anomalies in Tibetan Plateau and positive anomalies are present in its southern region(PC2 in positive phase),there is an anomalous anticyclone in North China,which weakens the northwest wind and is not beneficial for cold air moving from high latitude to the Tarim Basin,and the circulation pattern is hard to result in dust storm weather.Furthermore,the sea level pressure(SLP) increased over Tarim Basin and the direction of SLP gradient reversed,which resulted in the 10-m wind velocity slowing down,so the DSF decreased.From above all,it can be conclude that the thermal anomalies in Tibetan Plateau in May has important effects on the summertime dust storm frequency over Tarim Basin and the PC2 can be used as a prediction factor for the summertime dust storm occurrence.     

Overproduction of reactive oxygen species involved in the pathogenicity of Fusarium in potato tubers

Differences in virulence between Fusarium sulphureum and Fusarium sambucinum were compared. Changes in reactive oxygen species production and metabolism in inoculated slices of potato tubers were also compared. The result showed that Fusarium infection induced significant production of ROS, lipid peroxidation and loss of cell membrane integrity, but low activity of superoxide dismutase (SOD) and ascorbate peroxidase (APX). Compared to F. sambucinum, F. sulphureum led larger lesion diameters on potato tubers and slices. It resulted in more superoxide anion ($O_2^{-}$) and earlier peak of hydrogen peroxide (H₂O₂), but lower activity of catalase (CAT) and APX, and accompanied with higher malondialdehyde (MDA) content and lower cell membrane integrity. These findings suggested that overproduction of ROS involved in the pathogenicity of Fusarium in potato tubers.     

基于DSPACE的藏羌民族文化研究专题库建设

在长期的办学过程中,阿坝师范高等专科学校产生和积淀了有关藏羌民族文化研究的丰富的学术研究成果,通过DSpace系统构建藏羌民族文化研究专题库,可以解决藏羌民族文化成果管理存在展现不足、缺乏长期保存和获取困难的现状,进一步丰富图书馆的馆藏,促进资源的共享,提高学校的学术影响力。     

藏药湿生扁蕾的研究进展

从生物学及生态学研究、中药化学成分研究、药剂毒副作用及药理和临床应用等方面,系统阐述了近年来湿生扁蕾（Gentianopsis paludosa Ma）的研究进展。     

独一味等13个藏药植物种在西藏的分布和资源量调查

采用野外样地调查(样方法、样线法和普查法)和标本馆标本查阅的方法对西藏自治区所分布的濒危藏药材如独一味、波棱瓜、翼首草、桃儿七、苞叶雪莲、臭蚤草、甘青青兰、毛瓣绿绒蒿、岩白菜、白花秦艽、藏菠萝花、鸡蛋参和手掌参等资源在西藏自治区的分布、多度、生物量等进行了调查,在对这些藏药植物种分布区面积计算的基础上,估测了它们在西藏的最大资源量。结果发现;1)除藏菠萝花外的12种植物藏药资源的分布区和海拔范围比过去文献所报道的都有所扩大,但手掌参、波棱瓜等的资源锐减,在野外已很难发现,分布区的扩大是因为过去的调查不全面,而资源量的缩减主要是人类过度利用有关。2)岩白菜植物密度最高,多度也最大;岩白菜的生物量最高;波棱瓜盖度最高,手掌参密度最低,盖度也最低。3)臭蚤草的资源量最高,其次为白花秦艽和桃儿七等。该研究增补了藏药材分布的新资料,并提出了生境系数这个新概念来估测植物种的资源量。     

西藏牦牛遗传资源保护与利用

牦牛是我国丰富多样的畜种资源中重要的畜种之一,在遗传上是一个极为宝贵的基因库。本文阐述了西藏牦牛遗传资源的保种方法和利用途径,有助于西藏畜牧业的可持续发展。     

藏獒群体遗传变异的RAPD分析

[目的]从分子水平上研究藏獒群体的遗传变异状况,为藏獒种质资源的保护提供依据。[方法]采用RAPD技术对不同地区的20份藏獒基因组DNA进行分析,并用群体遗传学软件PopGene32测定藏獒群体的有效等位基因数（Ne）、Nei氏平均预期基因杂合度（H）和Shannon遗传信息指数（I）。[结果]共扩增出369条带,其中339条表现出多态性,多态性位点百分率为91.86%。PopGene32软件得到的藏獒群体的Ne、H和I值分别为1.7512、0.4162和0.6021。[结论]藏獒群体内存在着丰富的遗传变异。     

黄帚橐吾叶片气孔特征及对高寒环境的响应

为探讨黄帚橐吾（Ligularia virgaurea）对高寒环境的适应机制,对青藏高原的优势物种黄帚橐吾的叶表皮气孔特征进行观察,分析其对气候生态因子的响应。结果表明：黄帚橐吾叶片上、下表皮均分布有气孔,气孔分布无规律,随机散生排列,气孔器为无规则型,气孔密度与气孔指数相对较高。地理分异变量对黄帚橐吾叶表皮气孔长度的效应极其显著（P<0.01）。8个温度因子对黄帚橐吾叶片上、下表皮气孔长度效应极其显著（P<0.01）,ABT（年生物温度）、MTWM（最热月温）、MTGS（生长季温度）与WI（温暖指数）对上表皮气孔指数效应显著（0.01 < P < 0.05）;水分因子会影响黄帚橐吾叶片上表皮的气孔密度与气孔指数,而对下表皮气孔密度、气孔指数以及上、下表皮气孔长度无影响。黄帚橐吾叶表皮气孔特征在形态、数量及与环境关系的这些特点,反映了其对高寒极端环境的适应。