水稻栽培因素对北方粳稻产量及米质的影响[Ⅵ]--穗肥追肥时间对产量及米质的影响     

严光彬  李彦利  孟令军  王万成  贾玉敏  严永峰 《北方水稻》2005,(3):20-21

通过田间对比试验研究穗肥追施时间对水稻产量及米质的影响,结果表明,水稻的穗肥追施时间越晚,加工品质越好,而产量和食味品质明显降低.这种趋势以出穗前25 d为准,有跳跃式的质的变化.所以为了提高产量和增加食味品质,水稻的穗肥追肥时间不应晚于出穗前25 d.  相似文献   

不同利用方式下短花针茅草原生物量的形成规律     

韩国栋  贾鲜艳 《干旱区资源与环境》2001,(Z1)

在内蒙古包头市达茂联合旗哈雅教学牧场 ,采用随机区组法对短花针茅草原在不同刈割时期、次数和高度下的生物量形成规律进行了研究 ,旨在探索短花针茅草原的合理利用方式 ,为草原放牧畜牧业生产实践提供理论依据。研究结果表明 ,短花针茅草原对刈割高度较为敏感 ,适宜的刈割高度为 2 cm;短花针茅草原植物生长缓慢 ,再生能力差 ,不宜于频繁利用 ,一年适宜利用 1 -2次 ;考虑牧草产量和营养物质含量 ,一年两次利用的间隔期应为 2 -3个月 ;一年一次利用的最佳利用期为 8月中旬以后。  相似文献   

Effects of chlorine gas exposure on lung haemodynamic and respiratory function in intact and isolated perfused rabbit lungs     

ZHANG Hong-wei  ZHENG Zhe-rong  SONG Jun-feng  JIA Bin  WEN Guang-nan 《园艺学报》2002,18(5):510-513

AIM:To investigate the effect of high concentration of chlorine gas(Cl₂) exposure on lung haemodynamic and respiratory function in intact and isolated perfused rabbit lungs (IPLs). METHODS:8 intact and 10 IPLs were exposed to Cl₂ at high concentration(50×10^-4)for 20 min, as measured group, 8 additional intact and 9 IPLs, which were similarly treated but not exposed to Cl₂, served as controls. The changes of lung weigh of IPL(△W)、pressure of pulmonary artery(Pa)and venous pressure(Pv)、airway pressure and tidal volume(TV) were continuously measured and recorded simultaneously. RESULTS: In IPL group: While the perfusing blood flow was kept constant (133.3 mL/min), and Pv did not change, following the exposure, the Pa increased slightly, then the lung weight were increased significantly and the TV decreased . Hematocrit of perfusate of EIPL and parameters of lung water increased also. In intact group: Pa increased slightly, respiratory rate accelerated immediately, and TV decreased. CONCLUSION:Although mean Pa increased continuously and slightly in both intact and IPL group following the exposure to high concentration of Cl₂, the primary cause of edema was most likely to alter pulmonary capillary permeability. The respiratory rate accelerated and TV decreased due to exposure to Cl₂ enhanced hypoxia of intact rabbits.  相似文献   

成对或不成对反转试验设计     

王继华  贾青 《中国牛业科学》2002,28(3):1-5

本文系统探讨了反转试验（交叉设计）设计的数学模型。统计分析方法和原理以及设计要求，根据t-测验思想，给出了成对或不成对反转试验设计的原理和方法。  相似文献   

松节油工业现状与市场   总被引：2，自引：0，他引：2  

贾金莲 《林产化学与工业》2001,21(4):59-64

概述了国内外松节油的生产和市场分布现状，并对松节油市场消耗走势进行了分析，提供了历史数据和预测情况。  相似文献   

Detection of Allelic Variation in Chinese Wheat (Triticum aestivum L.) Germplasm with Drought Tolerance Using SSR Markers   总被引：2，自引：0，他引：2  

JING Rui-lian  CHANG Xiao-ping  Marcello Broggio  JIA Ji-zeng 《中国农业科学(英文版)》2002,1(10):1083-1088

Allelic variation in two domestic wheat landraces, Pingyaobaimai and Mazhamai, two cornerstone breeding materials and their derived cultivars with drought tolerance was detected by SSR (simple sequence repeat) markers. The clustering of 25 accessions showed that the similarity between Pingyaobaimai and Yanda1817, the latter was developed from the former, was 0.71, the highest one of all accessions, but the similarities were very low between these two accessions and other accessions including their derived cultivars. A similar situation was revealed between Mazhamai and its derived cultivars. Pingyaobaimai and its three derived cultivars shared three alleles at loci Xgwm526, Xgwm538 and Xgwm126 on chromosome arms 2BL, 4BL and 5AL, respectively. There were six shared alleles in Mazhamai and its derived cultivars, in order of Xgwm157,Xgwm126, Xgwm212, Xgwm626, Xgwm471 and Xgwm44 on chromosome arms 2DL, 5AL, 5DL, 6BL, 7AS and 7DC, respectively. Only one shared allele was detected between the pedigrees of Pingyaobaimai and Mazhamai. The difference of shared alleles in two cornerstone breeding materials and their derived cultivars revealed the diversity in Chinese wheat germplasm with drought tolerance and the complication in genetic basis of drought tolerance in wheat.  相似文献   

阿拉善查汗套海滩生态建设区最佳水文地质环境评价研究   总被引：1，自引：0，他引：1  

宝成  贾克力  范军  皇当俊  刘勇 《内蒙古农业大学学报(自然科学版)》2001,22(4):12-16

干旱沙漠区环境治理，水文地质环境是制约其它因素的关键。地下水位过高引起土壤盐渍化，地下水位过低则引起沙漠化。而正确确定地下水临界深度将成为查汗套海滩生态环境建设的瓶颈。本文提出地下水资源的允许开采量作为解决生态环境建设的重要途径之一，具有很好的资源效益和环境效益。  相似文献   

玉米优良自交系D黄212的选育研究   总被引：1，自引：0，他引：1  

张冬梅  王文田  贾荣革 《玉米科学》2002,10(Z1):042-045

以11个国外亲缘白粒玉米中晚熟地方品种或品系为基础群体,人工合成D团综合种选系集团,利用集团选系自D114与黄早4杂交,经10a分离选择,育成D黄212自交系.D黄212唐山夏播生育期88～90 d,一般产量4 500～5 250 kg/hm2,接种鉴定大、小斑病0.5-1级,青枯病株率0～16.5%,矮花叶病株率0,粗缩病0级.用该系选配杂交种15个,表现早熟、高产、抗病,其中已通过审定的品种4个,主要分布于冀、京、津、豫、鲁、辽、吉、蒙、黑、新等省市自治区,累计推广面积100万hm²。  相似文献   

院校合并后高校图书馆的特点及面临的问题   总被引：2，自引：0，他引：2  

贾丽侠  曹瑾  王杏利  王艾利 《农业网络信息》2006,(5):131-134

本文阐述了院校合并后，高校图书馆在馆藏资源、馆藏特色、馆藏文献的范围、信息化程度以及人力资源．流通工作等方面的特点。提出了院校合并后图书馆亟待解决的几个重要问题。  相似文献   

小美旱杨防护林对林带下土壤盐分均衡的影响     

刘静  贾忠权  董凤香 《浙江林学院学报》2007,24(2):186-191

通过测定小美旱杨Populus simonii×(Populus pyramidalis Salix matsudana)‘Poparis’标准木耗水量、树体不同部位储盐质量浓度和标准木生物量,推算12年生小美旱杨全生长期耗水量中总盐分质量浓度以及小美旱杨采伐时可带离的盐分,分析小美旱杨水分代谢过程对林下土壤-潜水系统盐分均衡的影响。结果表明,小美旱杨耗水中所含盐分离子的92%左右进入林下土壤-潜水系统中,其余随采伐被带离,但小美旱杨农田防护林带蒸腾造成的林下积盐在灌区积盐中仅占很小的比例。小美旱杨对营养元素的选择性吸收和对有害离子的拒吸作用,对林下土壤的可溶盐离子组分比例有一定的影响,主要表现是使进入土壤-潜水系统的Ca2 组分比例减小。表9参15  相似文献