南方型紫花苜蓿耐盐细胞系的筛选及生理特性分析     

马进  刘志高  郑钢 《中国草地学报》2011,33(4)

以NaCl为选择因子,对长期继代培养的紫花苜蓿愈伤组织进行选择,筛选出耐1.2%NaCl的耐盐细胞系并对其进行生理分析,结果表明:耐盐细胞系对逆境的忍受能力高于对照,积累的脯氨酸和可溶性蛋白含量也高于对照,维持着较高的K+/Na+比,在盐分胁迫下能维持较高的超氧化物歧化酶(SOD)和过氧化物酶(POD)活性。  相似文献   

CjFRO2在转基因枳中的整合与表达     

刘小丰  彭爱红  许兰珍  雷天刚  姚利晓  何永睿  陈善春 《果树学报》2011,(5):808-813

三价铁螯合物还原酶（Ferric-chelator reductase,FCR）在植物对三价铁的吸收过程中起着关键作用,导入外源三价铁螯合物还原酶基因是改良植物耐缺铁能力的有效途径。香橙（Citrus junos Sieb.ex Tanaka）是目前表现最好的柑橘耐缺铁砧木之一,在铁胁迫时,香橙三价铁螯合物还原酶基因（...  相似文献   

川南丘陵区近30 a来土壤养分时空变化   总被引：1，自引：0，他引：1  

王珊  廖桂堂  熊鸿焰  罗侯勇  张玎  代光银 《水土保持通报》2015,35(5):289-295

[目的]通过研究川南丘陵地区区域尺度上土壤养分的空间分异特征和时间变化特点,为该区域的土壤质量管理和农业可持续发展服务。[方法]基于GIS技术和地统计学方法,分析1982—2011年川南丘陵地区宜宾市南溪区长兴镇耕地土壤有机质、全氮、碱解氮、有效磷、速效钾的时空变化情况。[结果](1)研究区5种土壤指标中,有效磷的变异系数最高,其余指标变异系数在22.18%~37.03%,属中等程度变异。(2)结构分析表明,1982年时土壤养分的块基比为25%~75%,属中等变异,结构因素和人为因素对其都有影响;到了2011年,各指标空间自相关性变弱,人为因素占主导作用。(3)克里格插值显示,研究区近1/2区域土壤氮素偏高,全氮和碱解氮含量在高等级及以上面积分别占39.26%和47.94%;磷素虽略有上升,但有52.68%的区域有效磷含量在5mg/kg以下,属严重缺磷;钾素含量在中上等级区域面积减少,大部分在中下水平,甚至出现了极低水平。[结论]经过近30a土地利用后,整体上研究区土壤养分北高南低,且呈重氮,轻磷,忽钾的态势,研究区以南要注意控制氮肥的输入,补充磷、钾肥。  相似文献   

Populations of inshore serranids across the Canarian Archipelago: Relationships with human pressure and implications for conservation     

Fernando Tuya  Pablo Sanchez-Jerez 《Biological conservation》2006,128(1):13-24

We investigated spatio-temporal variability in the abundances and biomasses of four species of inshore serranids (the dusky grouper Ephinephelus marginatus, the island grouper Mycteroperca fusca, the painted comber Serranus scriba, and the blacktail comber S. atricauda) throughout the Canarian Archipelago (central-east Atlantic Ocean) with underwater visual transects. By means of a multiscaled sampling design spanning three orders of magnitude of spatial variability (from 10 s of meters among replicated 100 m² transects to 100 s of kilometres among islands) and four sampling periods, we related differences in the distributions of serranids to differences in the degree of human pressure, such as fishing intensity and human population. Differences in human pressure among islands provide the most parsimonious explanation for many of the consistent inter-island differences in the abundance and biomass of the analyzed species. Larger-bodied serranids (E. marginatus and M. fusca) are more vulnerable than the smaller species (S. scriba and S. atricauda). In fact, the larger, more vulnerable species have been almost completely extirpated from the most intensely fished islands. Our results show that the larger groupers have been overexploited throughout the Canary Islands, and highlight the urgent need for stringent management measures and better control of littoral reef fish resources.  相似文献   

宁南山区土壤酶活性特征及其与肥力因子的关系   总被引：10，自引：0，他引：10       下载免费PDF全文

安韶山  黄懿梅  刘梦云 《中国生态农业学报》2007,15(5):55-58

分析了黄土丘陵区土壤酶活性与土壤肥力因子之间的关系。相关分析结果表明,土壤有机质与全N、速效磷、速效钾等密切相关,同时与土壤几种酶活性有较好的相关性。土壤酶活性依赖于有机质,当有机质含量增加时,酶积极参与其转化分解过程,活性提高。脲酶、蔗糖酶活性与土壤N、P、K含量关系最大,土壤速效钾与蔗糖酶活性关系最大。通径分析结果表明:土壤肥力因子对脲酶活性的直接作用顺序为有机质>速效钾>速效氮>阳离子交换量>全N>速效磷>物理性黏粒>土壤pH。有机质是影响土壤脲酶活性、碱性磷酸酶活性的主要因素,速效钾是影响蔗糖酶活性的最主要因素。  相似文献   

土壤水溶性盐基离子的高光谱反演模型及验证   总被引：3，自引：2，他引：3  

代希君  张艳丽  彭杰  罗华平  向红英 《农业工程学报》2015,31(22):139-145

土壤水溶性盐基离子是诊断土壤盐渍化类型与盐渍化程度的重要依据,利用光谱技术快速获取土壤水溶性盐基离子含量数据,可为土壤盐渍化类型与盐渍化程度的诊断提供新的技术和手段。该研究通过采集新疆5个不同地区399个土样的反射率与水溶性盐基离子数据并进行31种光谱预处理方法,分析了不同水溶性盐基离子(HCO3-、Cl-、SO42-、K+、Na+、Ca2+、Mg2+)与高光谱反射率之间的相关性;采用K-S(Kennard-Stone)方法挑选出299个样品,针对每种离子使用偏最小二乘回归(partial least squares regression,PLSR)分别建立32个高光谱定量反演模型,优选最佳反演模型,并单独使用100个样品对估测模型进行检验。结果表明:不同离子的最佳反演模型所使用的预处理方法存在差异,其中仅有Cl-和Ca2+、SO42-和Mg2+所使用的预处理方法相同,其他离子则不同;不同离子的反演精度也不同,HCO3-和Ca2+构建的模型相对分析误差(relative percent deviation,RPD)分别为2.67、2.57,模型具有很好的预测能力。Cl-、SO42-和Mg2+所构建的模型RPD分别为2.05、2.10和2.14,表明这三者建立的模型具有较好的预测能力。K+建立的模型RPD仅为1.11,不能对样品进行预测。Na+构建的模型RPD为1.83,表明该离子所建模型只能对样品进行粗略估测。研究结果为探究水溶性盐基离子的高光谱反演增添了新的内容,为土壤盐渍化监测的深入和推进提供了新的思路和方法。  相似文献   

华南海岛土壤形成的地球化学   总被引：5，自引：0，他引：5  

GONG Zi-Tong  HUANG Biao 《土壤圈》1995,5(4):333-342

The soils in South China sea Islands(SCSI)were divided into three types,nmaely,phospho-calc soils,skeletisols and coastic solonchake,which were derived from bio-clastic and strongly calcareous sediments.In comparison with their parent materials,the phospho-Calc soils have higher contents of P,Zn Cu,Ba,and Cd,which tend to increase gradually with time,and lower contents of Mg,Ca,Sr,B,V,Pb,and Mo,which tend to decrease by degrees with time,The above-mentioned constituents in skeletisols and coastic solonchaks are similar to those in their parent materials except for P and Na,The factors affecting element distribution are mainly special bioclimate and parent material,meanwhile,resulting in the remakable influence on element distribution through soil-forming time.  相似文献   

宁夏南部黄土丘陵区退化天然草地改良效果综合评价     

刘库谢应忠  马红彬 《水土保持研究》2007,14(4):131-133

采用多层次模糊综合评判法,综合分析了宁夏南部黄土丘陵区不同改良措施下的改良效果,结果表明：“88542”整地＋播种综合评判值最高,达到5.9188,改良效果最好,施肥和封育的综合评判值其次,带状翻耕＋播种的综合评判值最低,仅为2.7750,远低于对照。  相似文献   

毕节地区人口和经济因素对生态自然修复的影响   总被引：3，自引：0，他引：3       下载免费PDF全文

罗林 《水土保持通报》2003,23(1):70-72

新疆南疆属于极端干旱生态脆弱带,土壤风蚀已严重制约着南疆绿洲农业的可持续发展。在分析了造成南疆绿洲区土壤风蚀主要因素的基础上,探讨了风蚀造成的危害,提出了保护、恢复与重建绿洲外缘的自然植被、加强绿洲内部防护林体系的建设、调整种植结构和进行农作物留茬覆盖等防治土壤风蚀的综合治理措施。  相似文献   

Organic carbon stocks and soil erodibility in Canary Islands Andosols   总被引：3，自引：0，他引：3  

A. Rodríguez Rodríguez  C.D. Arbelo  J.A. Guerra  J.L. Mora  J.S. Notario  C.M. Armas 《CATENA》2006,66(3):228-235

Soil organic carbon (SOC) plays a key role in the structural stability of soils and in their resistance against erosion. However, and as far as andic soils are concerned, these mechanisms and processes, as well as the influence of the different types of SOC on aggregate stability, are not fully understood. The targets of this paper are: (i) to determine the content and forms of SOC in Andosols under evergreen forest vegetation [laurel (Laurus) and heather (Erica) forest] and (ii) to find out the role of soil organic matter (SOM) in the aggregate stability and in the resistance of Andosols to water erosion. Soil samples have been collected in 80 sites in a 40 km² area under udic soil moisture regime. In them, fulvic and humic acids, Walkley–Black SOC, pyrophosphate-extractable SOC, Fe and Al, potassium sulphate extractable SOC, dissolved SOC, acid oxalate-extractable Fe, Al and Si, USLE K-factor and aggregate stability have been determined. The Andosols over volcanic ash are Aluandic Andosols (non-allophanic Andosols), whereas over basaltic lava flows are Silandic Andosols (allophanic Andosols). The surface (0–30 cm) samples analyzed contain 9.5–30 kg C m^− 2 being significantly higher in allophanic Andosols (p < 0.5). Organic carbon adsorbed onto the mineral fraction (extractable pyrophosphate, C_p) accounts for 35–55% of the total SOC. All samples show a high stability to slaking and raindrop impact, being the first one highly correlated (r = 0.6) with pyrophosphate extractable C (C_p), Fe (Fe_p), and Al (Al_p) in allophanic Andosols, unlike non-allophanic ones. The stability to raindrop impact correlates with pyrophosphate extractable C (C_p) and Fe (Fe_p) in both types of soils (r = 0.3–0.6, p < 0.05). These findings suggest that the high stability to both slaking and water-drop impact is due to the occurrence of allophane–Fe–OC complexes, rather than to the total OC, and the active Fe and Al forms, generated by the weathering of volcanic materials, constitute an essential constituent responsible for C sequestration and resistance to degradation in these soils.  相似文献