土壤学发展历程、研究现状与展望

土壤学在农业可持续发展和生态环境建设中发挥了极其重要作用。随着现代科学技术和社会经济的快速发展,土壤学正在经历从传统向现代土壤学的转变。本文简单回顾了国际和中国土壤学的发展历程,分析了土壤学研究现状,指出了中国土壤学的研究特色和主要研究成果。同时,分析了当前土壤学研究领域所面临的问题和挑战,对其未来的发展趋势做出了展望,为土壤学的发展指明了研究方向。     

Effects of Exogenous 24-epibrassinolide on Photosynthetic Physiology of CottonSeedlings under Low Temperature

[Objective] The objective of this study was to investigate the effects of exogenous 24-epibrassinolide (EBR) on the photosynthetic physiology of cotton seedlings under low temperature and to provide basis for improving the cold tolerance of cotton by using EBR as growth regulator. [Method] Taking CCRI 60, Lumianyan 28 and Simian 3 as materials, a field experiment was carried out in Institute of Cotton Research of CAAS(Anyang county, Henan province). Before the first low temperature treatment, the cotton seedlings were sprayed with distilled water (Control) and different concentrations of EBR (0.1 mg·L^－1 and 0.2 mg·L^－1), respectively. After 3 days, the relative electrical conductivity, chlorophyll content, rapid chlorophyll fluorescence induction kinetic curve (OJIP) and fluorescence parameters were measured. [Result] Under low temperature, the relative conductivity of CCRI 60, Lumianyan 28 and Simian 3 spraying with EBR decreased by 17.7%～32.8% compared with control, and there was no significant difference between CCRI 60 and Lumianyan 28 in different concentrations of EBR treatments, butthe relative conductivity of Simian 3 treating with 0.2 mg·L^－1 EBR was significantly lower than those treatments with 0.1 mg·L^－1 EBR . The chl a and chl b contents increased by 9.7%～32.6% and 15.0%～18.9%, respectively. The maximum photochemical efficiency of photosystemⅡ (F_v/F_M) and photosynthetic performance index on absorption basis(PI_ABS) increased significantly. PI_ABS of CCRI 60 increase the maximum by 75.6% using 0.1 mg·L^－1 EBR. Lumianyan 28 and Simian 3 increased the maximum by 101.1% and 265.6% using 0.2 mg·L^－1 EBR, respectively; Absorbed photon flux per cross section (ABS/CSm), electron transport flux (further than QA) per active reactive center (ETo/RC) and probability for electron transport (φEo) are significantly increased. [Conclusion] Exogenous EBR can enhance the ability of low temperature tolerance of cotton seedlings and alleviate the inhibition of photosynthesis in cotton at low temperature. The study showed that 0.1 mg·L^－1 EBR performs well in CCRI 60 and 0.2 mg·L^－1 in Lumianyan 28 and Simian 3.     

Interaction mechanism and kinetics of ferrous sulfide and manganese oxides in aqueous system

Journal of Soils and Sediments - The oxidation of ferrous sulfide (FeS) causes soil acidification and the release of toxic heavy metal ions. Manganese oxides usually participate in the oxidation of...     

Erratum to: Interaction mechanism and kinetics of ferrous sulfide and manganese oxides in aqueous system

Journal of Soils and Sediments -     

环巢湖农家乐发展现状及对策建议

该文介绍了环巢湖农家乐的发展现状,分析了环巢湖农家乐旅游发展中存在的问题,并提出了进一步发展环巢湖农家乐的对策建议。     

海滨雀稗EST资源的SSR信息分析及EST-SSR标记开发

本研究探讨海滨雀稗EST序列中SSR位点的分布特征,开发EST-SSR引物分析其在草坪草种质资源遗传多样性研究中的应用。利用SSRIT软件对81220条海滨雀稗EST序列进行SSR位点搜索,分析EST-SSR的分布和特点,并利用Primer 3.0软件设计50对引物,选择10份草坪草对引物进行有效性和多态性检测。结果表明,从13705条海滨雀稗EST序列中检测到了22721个SSR位点,出现频率为16.87%。三核苷和单核苷酸重复为主要类型,所占比例分别为31.71%和29.28%。在检测到的163种基元中,出现最多的重复基元是A/T,其次是CCG/CGG和AGC/CTG。选择合成了50对EST-SSR引物,以海滨雀稗‘Adalady’基因组DNA为模板进行PCR扩增,其中37对引物能扩增出条带。利用这些引物对10份草坪草品种进行多态性检测,其中12对引物的扩增结果具有多态性。利用开发的EST-SSR标记对10份草坪草进行聚类分析,可将其分为4类。利用海滨雀稗EST序列开发SSR标记是可行的,开发的EST-SSR标记能有效用于草坪草遗传多样性研究。     

惰性粉气溶胶横向环流与直排施粉防虫效果比较研究

通过施粉后粮库内采样,实验室培养,检查试虫死亡率的方法,对比了平房仓内横向通风系统下,利用环流与直排两种惰性粉气溶胶施粉方式的防虫效果。结果表明:两种方式都能使惰性粉气溶胶贯穿粮堆,形成最低致死浓度,对长角扁谷盗、玉米象、谷蠹和赤拟谷盗均能起到一定的防治效果,环流施粉好于直排施粉,在惰性粉分布的均匀性上,两者均没有表现出明显的优势。     

Comparison of methods for extracting high-throughput sequencing RNA from Korean pine seeds

Korean pine(Pinus koraiensis Sieb. et Zucc.) is an ecologically and economically important tree species in East Asia. Molecular studies of seed development of this species are limited due to the lack of effective RNA extraction protocols. This study aimed to obtain an effective method to extract high-quality RNA from Korean pine seeds. The TRIzol kit and CTAB methods were used to extract the total RNA from Korean pine seeds at different developmental stages. The bands of RNA extracted by CTAB were not clear, whereas the bands of RNA extracted by the TRIzol kit were brighter and clearer, indicating higher quality and integrity of the RNA products extracted by the TRIzol kit. The 28 S r RNA band was approximately1.5- to 2-fold brighter than the 18 S r RNA band on the agarose gel electrophoresis. The absorbance value A260/280 was 1.8–2.0, and the absorbance value A 260/230 was [1.9. The Bioanalyzer RNA integrity results showed that the RNA integrity number of the RNA extracted using the TRIzol kit was acceptable for high-throughputsequencing. Therefore, the total RNA extracted using the TRIzol kit method can be used for high-throughput sequencing and other molecular biology experiments.     

浙江安吉竹笋加工和废弃物处理现状及发展对策

对浙江省安吉县竹笋加工业的现状和加工产生的废弃物处理情况进行了调查分析。调查发现:安吉竹笋加工产品种类丰富,但企业数量不断减少;笋加工原料来源广泛;废水经处理后能够合格排放;固体废弃物主要用作牲畜饲料。安吉竹笋加工中存在的问题主要表现为:劳动力需求量大,工资成本高;废弃物处理成本高,再利用率低;竹笋市场开拓力度不足。文章针对竹笋加工中存在的问题提出了相应的解决对策。     

浙江安吉县竹产业发展趋势及原因分析——基于2010—2015年人力资源招聘信息的实证分析

为了揭示安吉县竹产业发展趋势,进一步分析其原因,本文选取了安吉县2010-2015年春、秋季共10次招聘会的招聘数据信息,对安吉县竹产业发展趋势进行了分析。结果显示:近年来安吉县竹产业招聘企业和岗位数量及其比例均不断下降,反映了安吉竹产业正处于逐步下行的趋势,其在国民经济中的相对地位也在不断下降。分析其原因主要是:竹产品市场份额减少,产品相对过剩;中西部竹产业发展带来冲击;在竹资源培育方面投入劳动力不足,在加工方面机械化程度低;竹产业自身转型急需升级等,并就此提出了对策建议。