重庆开县3个锦橙品种留树贮藏试验初报     

周贤文  胡佳羽  胡万芬  李恢安  方正茂  张立  付世军 《中国园艺文摘》2011,27(9):13-14

对重庆市开县3个锦橙品种留树贮藏效果进行探索,结果表明,‘开陈72-1’、‘开盛76-8’和‘北碚447’3个锦橙品种留树贮藏至2月下旬,能维持较高的坐果率、商品果率、外观色泽和可溶性固形物含量;‘开陈72-1’最适宜做开县锦橙留树贮藏品种。  相似文献   

Cellular and ultrastructural changes in the seedling roots of upland rice (Oryza sativa) under the stress of two allelochemicals from Ageratina adenophora     

GUO‐QING YANG  FANG‐HAO WAN  JIAN‐YING GUO  WAN‐XUE LIU 《Weed Biology and Management》2011,11(3):152-159

Two sesquiterpene‐derivative compounds, 4,7‐dimethyl‐1‐(propan?2‐ylidene)–1,4,4a,8a‐tetrahydronaphthalene‐2,6(1H, 7H)‐dione (DTD) and 6‐hydroxy‐5‐isopropyl‐3,8‐dimethyl?4a,5,6,7,8,8a‐hexahydronaphthalen‐2(1H)–one (HHO), are the major putative allelochemicals of the aqueous leachates of Ageratina adenophora. A laboratory experiment was conducted, using the hydroponic method, to evaluate the cellular and ultrastructural changes in the seedling roots of upland rice under the stress of DTD and HHO. The subsequent changes were observed in the treated upland rice roots in comparison with their controls. The scanning electron microscopy results showed that the DTD‐treated root tip cells turned into an irregular arrangement and shape and that most of them were wizened, with a poor cytoplasm. In the HHO treatment, the root tips had many irregularly shaped cells, with a greater number of sloughing cells, as well as short, wide cells that resulted in spherical and wider, but shorter, roots. At the ultrastructural level, DTD and HHO induced irregularly shaped and lobed nuclei, increased cytoplasmic vacuolation, reduced ribosome density and dictyosomes, and a reduced number of mitochondria in the cells, which indicated limited protein transportation and a reduced capability to export substances for cell development and growth in the upland rice seedling roots. The overall effect of HHO on the upland rice seedlings was more pronounced than that of DTD.  相似文献   

GIS支持下山东省土地自然质量评价研究   总被引：1，自引：0，他引：1  

胡业翠赵庚星  方玉东 《西北农林科技大学学报(自然科学版)》2001,29(Z1):39-43

在地理信息系统 (GIS)的支持下 ,结合 Visual Foxpro5 .0及农业实用多元分析程序包 (APMP)对山东省土地自然质量进行了评价。以 GIS叠加分析模型 ,通过图形与其属性库的对应统一 ,利用 APMP程序包 ,以回归分析、主成分分析、聚类分析等定量模型 ,实现评价单元的划分、参评因素的筛选及权重的确定 ,基本实现了土地评价的自动化流程 ,适时满足土地信息数字化的要求  相似文献   

有机磁化复合肥中氮的溶出特性研究     

方卢秋  李晓燕  郝步珍 《云南农业大学学报(自然科学版)》2003,18(4):404-407

 有机磁化复合肥是利用城市生活垃圾和粉煤灰,根据土壤养分特性及植物营养规律,配以所需的无机营养肥料,经工艺生产及磁化处理而成。笔者研究了柠檬酸用量、温度、振荡时间、静置时间对有机磁化复合肥中氮溶出特性的影响。结果表明:有机磁化复合肥显酸性;柠檬酸引起的溶液pH值变化对氮的溶出影响不大;氮的溶出主要受温度和静置时间的影响,随温度和静置时间的增加而增加,氮的溶出具有缓释性;柠檬酸和振荡对氮的溶出组分中的铵态氮有较大的影响,说明有机磁化复合肥具有一定速效性。  相似文献   

城市化对上海土壤环境质量的影响   总被引：21，自引：0，他引：21  

HU Xue-Feng  WU He-Xin  HU Xing  FANG Sheng-Qiong  WU Chen-Juan 《土壤圈》2004,14(2):151-158

Heavy metal contents in the soils in the Baoshan District of Shanghai were monitored to evaluate the risk of soil environmental quality degradation due to rapid urbanization and to reveal the ways of heavy metal accumulation in soil during rapid urban sprawl. It was found that the soils in this district were commonly contaminated by Pb, Zn and Cd. Evaluated with a geo-accumulation index (I_geo), the rate of Pb contamination in soils was 100% with 59% of these graded as moderate-severe or severe; Zn contamination reached 59% with 6% graded as moderate-severe or severe; and Cd contamination was over 50%, with one site graded as moderate-severe and another severe-extremely severe. Metal contamination of soils around the Shanghai metropolis was mainly attributed to trame, industrial production, wastewater irrigation and improper disposal of solid wastes. Because of continuing urbanization, the cultivated land around the metropolis should be comprehensively planned and carefully managed. Also the soil environmental quality of vegetable production bases in this area should be monitored regularly, with vegetables to be grown selected according to the degrees and types of soil contamination.  相似文献   

关于畜牧生产系统稳定机制的探讨     

张运涛  方德罗 《中国生态农业学报》1994,2(4):18-21

畜牧生产系统实质上是开放的人工生态系统。建立高效、整体功能良好的畜牧生产系统是现代畜牧业的主要目标。探讨畜牧生产系统的稳定机制对于畜牧业的发展具有重要的理论指导意义。畜牧生产系统的稳定机制包括内源稳定机制和外源调控机制两个方面。其中内源稳定机制由系统的整合性、多样性、替代性以及生态位均质性构成，外源调控机制主要指等衡调控机制。  相似文献   

上思县海南嗀活动区的水鸟研究   总被引：1，自引：0，他引：1  

周放  陆舟  余丽江  房慧伶  潘红平  徐蕴丽 《广西农业生物科学》2003,22(4):249-252

海南（开 鸟）(Gorsachius magnnficus)是世界上最为濒危的鸟类之一。在上思县海南的活动区，分布有水鸟32种；其中在海南（开 鸟）主要觅食地浅水区活动的有14种，包括11种白昼活动的水鸟和3种夜行性水鸟，海南（开 鸟）属夜行性水鸟。由于生境使用时间不同，海南（开 鸟）与大部分白昼活动的水鸟形成生态分隔；夜鹭在觅食生境的使用和活动时间上，与海南（开 鸟）重叠最多，有可能对海南（开 鸟）产生重要的生态影响，值得进一步深入研究。研究还表明，冬季和初春是调查海南（开 鸟）的分布和数量的重要季节。  相似文献   

金枪鱼酶解液脱色工艺及其对腥味物质和金属元素的影响     

刘建华  季金箭  王斌  方亦舟  丁玉庭 《核农学报》2015,29(4)

为了研究活性炭对金枪鱼酶解液脱色的最佳条件,本文利用活性炭对金枪鱼暗色肉酶解液进行处理,研究活性炭添加量、pH值、温度(T)和脱色时间(t)对脱色率和蛋白质损失率的影响,采用正交试验对脱色工艺进行优化,同时探究了活性炭脱色工艺对酶解液腥味物质和金属元素含量的影响.结果表明,金枪鱼暗色肉酶解液最佳脱色条件为活性炭添加量3％、pH值3.0、温度70℃、时间1h.该条件下脱色率为89.77％±0.77％,蛋白质损失率为13.47％±0.72％;脱色后酶解液挥发性物质含量降低了85.39％,其中三甲胺、己醛、壬醛等特征腥味物质显著降低;活性炭对Pb的吸附作用较明显,其吸附率为93.2％,而对其他金属元素的吸附率不大.研究表明,经过活性炭处理过的酶解液颜色浅,腥味低,具有一定的应用前景,可为酶解液的进一步利用提供依据.  相似文献   

川中丘陵区不同利用方式的土壤养分特征研究   总被引：7，自引：0，他引：7  

胡玉福  邓良基  张世熔  方从刚  郑小佳 《水土保持学报》2006,20(6):75-78

通过实地调查、土壤采样分析和数理统计结合的方法，对川中丘陵区5种土地利用方式（水田、旱地、菜地、林地和荒草地）的土壤养分状况进行对比分析，结果表明．土地利用方式对土壤有机质、全氮、全钾、全磷、碱解氮、速效钾和速效磷含量的影响达极显著（或显著）水平；在5种土地利用方式中．土壤有机质和全氮含量由高到低的顺序为：水田〉林地〉菜地〉旱地〉荒草地；土壤全钾和速效钾含量由高到低的顺序为：水田〉菜地〉旱地〉林地〉荒草地；土壤全磷含量由高到低的顺序为：菜地〉旱地〉林地〉水田〉荒草地。  相似文献   

几种化学药物混合物熏气催熟杧果的综合效应     

方中斌  宋烽瑛 《广西农业生物科学》2006,25(2):168-171

为解决果后熟过程中存在的黄熟程度不均匀、易感炭疽病和蒂腐病等问题,进行几种化学药物的混合物所产生气体催熟果的试验。结果表明:最佳的处理(处理Ⅱ),果黄熟仅需4 d,防炭疽病效果可达93%,防蒂腐病效果可达100%,可溶性固形物含量提高1%以上,轻耗仅为自然后熟的17.38%,果皮色泽鲜艳,果肉硬,风味佳,外观整洁,商品率高。该处理方法简单易行。  相似文献