长期定位施肥对旱地黑垆土钾素空间分布及有效性影响

对黄土高原长期定位施肥24年后土壤钾素的空间分布及其有效性进行研究。结果表明：不同施肥处理0-20cm土层各形态钾素含量均高于20-40cm的,施用化肥处理的非特殊吸附性钾除外,且60cm以下随土层深度不断加深,不同形态的钾素含量呈逐渐降低的趋势。长期施用化肥0-300cm土层中各形态钾素含量均表现出明显低于CK的趋势;长期施用有机肥或有机肥与化肥配施明显增加了各形态钾素含量,说明施用有机肥能维持黑垆土速效钾的平衡,缓解非交换性钾的下降趋势。相关分析表明,土壤速效钾与土壤中水溶性钾之间呈极显著相关,与非特殊吸附性钾呈显著相关,与特殊吸附性钾和非交换性钾无相关性。长期施肥可提高小麦植株的钾素吸收量,茎含钾量丰富,占总植株的36.67%,籽粒钾含量仅占植株钾总量的9.74%。     

镧对镉胁迫羽衣甘蓝的调节效应

[目的]为花卉植物用于cd污染土壤栽培提供依据。[方法]采用水培试验研究了镧（工丑）对羽衣甘蓝受到镉（Cd）胁迫的调节效应。[结果]低浓度的cd对羽衣甘蓝的出芽率、株高、根系、地上和地下鲜重与千重等指标均有一定的抑制作用,高浓度的cd对其有明显的抑制作用,而一定浓度的La可以缓解这种抑制作用。[结论]5mg／LLa缓解高浓度cd对羽衣甘蓝种子出芽以及生长等各项指标的抑制作用效果最好。     

小洲村古村落旅游开发探析

主要探讨了小洲村古村落旅游资源情况、古村落旅游发展状况以及需要解决的问题。     

蛋白质组学研究技术及其在果树学中的应用

蛋白质组研究是当今生命科学发展的一个新的增长点,它能阐明基因组所表达的真正执行生命活动的全 部蛋白质的表达规律和生物功能。简要介绍了蛋白质组学产生的科学背景、研究方法和研究内容。蛋白质组学研究 方法主要有双向聚丙烯酰胺凝胶电泳(2D-PAGE)、质谱(Mass-spectrometric)技术、蛋白质芯片(Protein chips)技术、酵母 双杂交系统(Yeast two-hybrid system)、双向高效柱层析和生物信息学等。其应用的范围包括植物群体遗传学、在个体 水平上植物对生物和非生物环境的适应机制、植物的发育和组织器官的分化过程,以及不同亚细胞结构在生理生态 过程中的作用等诸多方面。同时展望了植物蛋白质组学研究前景以及蛋白质组学技术在果树学中的应用前景。     

高校图书馆大流通环境下的读者教育与管理探析

大流通运行模式已在高校图书馆普遍运用,其优势非常明显,但存在的问题也比较突出。通过对大流通的内涵、特征及其在大流通环境下存在的问题进行分析,指出了产生问题的主要原因,提出了图书馆加强读者教育与管理的思路。     

家庭绿化植物种类选择

通过对家庭居室不同空间特点的分析,根据家庭绿化的趋势,从绿化植物材料的适应性、观赏性、生态性和经济性方面探讨了家庭绿化材料的选择,以期为居室绿化提供参考依据。     

Spatial-temporal Patterns of Land-use Change in Typical Transect Area Along China National Highway 106 During 1996-2008

Based on land-use database updated with the survey of 1996, 2000, 2004 and 2008, this paper analyzed the land-use changes in the typical transect area along National Highway 106 with the aid of GIS technology and quantitative models. The results showed that arable land had been continuously decreased from 1996 to 2008, with a loss of 65.85× 10^3 hm2 and an average decrement of 5.49×10^3 hm^2 per year, and the loss in northern areas was larger; garden land and woodland were gradually centralized to the predominance area with an increment of 25.73×10^3 hm2 and 22.37×10^3 hm2, respectively; residential and industrial land increased year after year, and the transportation land showed the equalized developing spatial pattern; the increment of construction land and encroachment on arable land in the area were deeply influenced by the national macroscopic land-use policies, the rapid advance of urbanization and the development level of the regional economy. Through this case study, it is suggested that differential land- use policies should be adopted to create good environmental conditions to guarantee food security and to promote the economic development.     

Production of Transgenic Anliucheng Sweet Orange (Citrus sinensis Osbeck) with Xa21 Gene for Potential Canker Resistance

Citrus canker, an epidemic quarantine disease caused by Xanthomonas axonopodis pv. citri, has brought a great damage in citrus production worldwide. Herein, a rice PRR (pattern recognition receptor) gene Xa21 together with GUS reporter gene and hygromycin phosphotransferase gene (HPT) was introduced into Anliucheng sweet orange (Citrus sinensis Osbeck) via Agrobacterium-mediated transformation of embryogenic callus. The transgenic calluses were screened on MT basal medium containing hygromycin (HYG) and detected by histochemical GUS staining. The transgenic plantlets were recovered through somatic embryogenesis pathway. The regenerated plantlets were accustomed to and maintained in the greenhouse. The transgene integration of recovered plantlets was identified by PCR and Southern blot hybridization. It showed that all the transgenic plantlets tested had undergone single copy integration, the expression of Xa21 in eight different transgenic lines detected by qRT-PCR can be divided into three grades, high for T5 and T6, middle for T4 and low for the rest. The tolerance to citrus canker disease of the three recovered transgenic lines T2, T4 and T6 was assessed by in vitro pin-puncture inoculation. The results showed that all the three transgenic lines conferred improved resistance to citrus canker bacterium infection and the T4 transgenic line displayed the highest resistance. The mechanism and feasibility of rice Xa21 in triggering innate immunity in citrus was briefly discussed.     

普通野生稻稻瘟病广谱抗性基因Pi-gx（t）的遗传分析和定位

【目的】探明来源于广西普通野生稻的稻瘟病抗源RB221与部分已知抗病基因水稻品种抗谱的异同,其抗性基因的遗传模式及在染色体上所处的位点,确定其抗病基因是否为新的抗病基因。【方法】采用从广西不同稻作区收集的8个稻瘟病菌系对抗源RB221和11个已知抗病基因的水稻品种进行抗谱测定,并对RB221抗病基因进行等位性分析、经典遗传分析及分子标记定位。【结果】抗源RB221的抗谱与11个已知抗病基因的水稻品种有差异,其对8个菌系均表现出抗病反应,在所有参试品种中抗谱最广。等位性测定结果表明,抗源RB221所携抗病基因与已知抗病基因品种所携带的Pi-3、Pi-7（t）、Pi-ta、Pi-K、Pi-b是不等位。经典遗传分析结果显示,抗源RB221对03-35E菌系的抗性受1对显性基因控制。SSR标记定位结果表明,RB221抗病基因定位于第2染色体的SSR标记RM240与RM1092之间,与RM240的遗传距离为1.3 cM,与RM1092的遗传距离为2.2 cM。【结论】抗源RB221的抗性基因Pi-gx（t）为新发现的抗病基因,位于第2染色体上,与第2染色体上已定位的抗性基因处于不同基因位点上。     

都市型现代农业综合发展水平评价方法研究

根据都市型现代农业的内涵和典型特征,建立了都市型现代农业综合发展水平的评价指标体系和评价方法。评价指标体系包括经济发展水平、社会发展水平和生态环境可持续发展水平3个评价指标体系,各级指标的权重根据层次分析法确定,评价方法主要基于灰色评估法。以此方法为基础,初步评价了北京都市型现代农业的综合发展水平。结果表明,北京都市型现代农业综合发展水平1990～2004年一直处于起步阶段,2005年跨入发展阶段,且都市型现代农业综合发展水平与经济发展水平的趋势一致。