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排序方式: 共有30条查询结果,搜索用时 15 毫秒
1.
作物不同基因型的磷素营养研究进展   总被引:4,自引:3,他引:4  
介绍了近年来植物磷素营养研究的发展趋势,强调了开发不同基因型作物品种耐低磷机理研究的重要性;综述了作物不同基因型低磷胁迫的根系形态构造的差异、根系分泌物及pH值的变化;低磷胁迫对水分利用效率、碳水化合物同化作用的影响、对膜脂过氧化及保护酶系统活性的影响、对叶片特征的影响、酸性磷酸酶(APA)活性与耐低磷胁迫的关系;磷素利用效率的基因位点(分子标记)的研究进展.  相似文献   
2.
Genetic diversity and relationships of wild goat grass (Aegilops tauschii Cosson) from Iran and Xinjiang,west China,as well as its weedy type from the Yellow River region of Shaanxi and Henan provinces in China were analyzed by simple sequence repeat (SSR) fingerprints.A high level of genetic diversity in Aegilops tauschii accessions from Iran was observed,and the richness of genetic diversity was followed by accessions from Shaanxi,Henan,and Xinjiang.The weedy type of Aegilops tauschii showed a close genetic relationship with the wild type from different regions in Iran.The results indicated that the weedy Aegilops tauschii found in the Yellow River region was most likely introduced from lran-the diversity center of Aegilops tauschii.The weedy Aegilops tauschii populations found in the Yellow River region may be brought into the central part of China as a weed species together with common wheat (Triticum aestivum L.) from the West during various periods of time in history.This finding has provided strong evidence for the introduction of common wheat from the West into China via the Silk Road,and also demonstrated the important role of the Silk Road in the exchange of agri-culture and other relevant technologies between China and the West.  相似文献   
3.
Genetic diversity and relationships of wild goat grass (Aegilops tauschii Cosson) from Iran and Xinjiang, west China, as well as its weedy type from the Yellow River region of Shaanxi and Henan provinces in China were analyzed by simple sequence repeat (SSR) fingerprinting. A high level of genetic diversity in Aegilops tauschii accessions from Iran was observed, and the richness of genetic diversity was followed by accessions from Shaanxi, Henan, and Xinjiang. The weedy type of Aegilops tauschii showed a close genetic relationship with the wild type from different regions in Iran. The results indicated that the weedy Aegilops tauschii found in the Yellow River region was most likely introduced from Iran—the diversity center of Aegilops tauschii. The weedy Aegilops tauschii populations found in the Yellow River region may be brought into the central part of China as a weed species together with common wheat (Triticum aestivum L.) from the west during various periods of time in history. This finding has provided strong evidence for the introduction of common wheat from the West into China via the Silk Road, and also demonstrated the important role of the Silk Road in the exchange of agriculture and other relevant technologies between China and the West.  相似文献   
4.
This paper provides a comprehensive review of literature related to the assessment of climate change impacts on crop productivity using climate,water and crop yield models.The existing studies present that climate change models with higher spatial resolution can be a way forward for future climate projections.Meanwhile,stochastic projections of more than one climate model are necessary for providing insights into model uncertainties as well as to develop risk management strategies.It is projected that water availability will increase in some parts of the world,which will have its own effect on water use efficiency and water allocation.Crop production can increase if irrigated areas are expanded or irrigation is intensified,but these may increase the rate of environmental degradation.Since climate change impacts on soil water balance will lead to changes of soil evaporation and plant transpiration,consequently,the crop growth period may shorten in the future impacting on water productivity.Crop yields affected by climate change are projected to be different in various areas,in some areas crop yields will increase,and for other areas it will decrease depending on the latitude of the area and irrigation application.Existing modelling results show that an increase in precipitation will increase crop yield,and what is more,crop yield is more sensitive to the precipitation than temperature.If water availability is reduced in the future,soils of high water holding capacity will be better to reduce the impact of drought while maintaining crop yield.With the temperature increasing and precipitation fluctuations,water availability and crop production are likely to decrease in the future.If the irrigated areas are expanded,the total crop production will increase;however,food and environmental quality may degrade.  相似文献   
5.
家禽硬嗉症以火鸡最多发,传统治疗方法是手术疗法,但该法弊多利少。采用6种不同的非手术疗法对火鸡硬嗉症进行治疗,认为经口灌服1.5%碳酸氢钠为最佳疗法。  相似文献   
6.
刘万代  李亮琴 《河南科学》1998,16(2):245-248
简介了作物干扰在杂草控制中的重要性,概述了作物干扰的两种主要形式:他感与竞争,分析了影响作物干扰的有关因素,提出了增强作物干扰能力、减轻杂草危害的可行措施:选育抗草品种,加强栽培管理和合理轮作与间套作。  相似文献   
7.
采用内置远红外线电加热管烘干机加热小麦 ,对物料层升温速度和温度分布均匀性与穿透风速的关系进行了单因素试验和四因素二水平的正交试验研究 ,结果表明 ,物料内层的升温速度及内外层温差均随穿透风速的增加而降低 ,内外层温差随加热时间先增大后减小 ;并给出四因素之间的较优参数组合  相似文献   
8.
作物抗旱性与作物生产   总被引:3,自引:0,他引:3  
在评述字研究者对作物抗旱性概念及其适应机理认识的基础上,分析了按期在作物抗旱性与作物生产方面的研究进展,讨论了植物生理学增强作物抗旱性,提高作物生产力方面的可能性和存在的问题。  相似文献   
9.
In the recent years, a plethora of computerized expert systems has been developed for various sectors of agriculture in India. The availability of low-cost computers, agricultural knowledge and information technology professionals are the principal reasons for the development of so many agricultural expert systems. Among all agricultural expert systems, the expert systems for crop protection need special mention. These expert systems are meant to be used by farmers and other persons without much experience of using computers. Hence, special care must be taken while developing them. The current paper develops a taxonomy for the expert systems for crop protection and briefly discusses four such expert systems for crop protection being used in India.  相似文献   
10.
作物生育期模拟研究进展   总被引:3,自引:0,他引:3  
综述了作物生育期模拟模型的研究概况以及水稻、小麦、棉花等作物生育期模拟的研究进展.  相似文献   
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