苹果果实轮纹病研究进展   总被引：30，自引：1，他引：29  

陈策 《植物病理学报》1999,29(3):193-198

 70年代后期以来,随着主栽品种的更迭,质优但感病的品种栽培面积扩大,苹果采摘前后大量烂果,逐渐成为果树生产上的突出问题。  相似文献   

Effects of salinity on growth,nutrient composition,fatty acid composition and energy metabolism of Scylla paramamosain during indoor overwintering     

Junming Zhou  Na Li  Huan Wang  Chunlin Wang  Changkao Mu  Ce Shi  Lei Liu  Ronghua Li  Yangfang Ye  Weiwei Song 《Aquaculture Research》2020,51(5):1834-1843

Three salinities (4‰, 12‰ and 25‰) were selected to determine the effects of different salinities on the growth, survival, nutrition and energy metabolism of Scylla paramamosain during indoor overwintering. Growth performance (survival rate, condition factor, hepatopancreatic index, weight gain rate and specific growth rate), nutrient composition (ash, moisture, crude fat, crude protein and total nitrogen), fatty acids, energy metabolites (glycogen, glucose, triglycerides, cholesterol and lactic acid) and energy metabolic enzymes (hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase) were measured and calculated. The results showed that S. paramamosain exhibited the best growth and survival at 25‰ and worst at 4‰ after overwintering. In addition to consuming crude fat, excess protein was also broken down to provide energy in the 4‰ and 12‰ groups. The content of unsaturated fatty acids in the 25‰ group was higher after overwintering. Glycogen and glucose consumption and triglycerides, cholesterol and lactic acid production were lowest in the 25‰ group. The activity of hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase was highest in the 4‰ group and lowest in the 25‰ group. The activity of hexokinase, pyruvate kinase, lactate dehydrogenase and succinate dehydrogenase in the hepatopancreas was higher than in the muscle. In conclusion, S. paramamosain uses less energy, has more unsaturated fatty acids and has a higher survival rate at a salinity of 25‰ after overwintering. The results of this study provide helpful information the indoor overwintering S. paramamosain in aquaculture production systems.  相似文献   

Overwintering behaviour affects distinctive flavour of mud crab Scylla paramamosain in commercial farms     

Lei Tang  Huan Wang  Hongling Wei  Chunyu Ye  Lizhi Chen  Hongzhi Yao  Ce Shi  Changkao Mu  Chunlin Wang 《Aquaculture Research》2020,51(1):29-40

In order to reveal the influence of overwintering behaviour on the flavour of Scylla paramamosain, this study selected crabs of before and after overwintering in SM (Sanmen County, Zhejiang Province), HP (Hepu County, Guangxi Province) and WN (Wanning city, Hainan Province). The contents of flavouring‐related substances in hepatopancreas, muscles and gonads were determined by high‐performance liquid chromatography (HPLC); taste activity value (TAV) and equivalent umami concentration (EUC) were calculated. The results showed that sweetish amino acids were mainly accumulated in muscles, umami amino acids were mainly accumulated in hepatopancreas, free nucleotides were mainly accumulated in gonads, and the EUC value in gonads was the highest. After overwintering, the content of sweetish, umami amino acids and free nucleotides in muscle and hepatopancreas decreased significantly, while the content of flavour‐tasting amino acids in gonads did not change significantly, but the content of umami nucleotides increased significantly. Therefore, overwintering behaviour decreased the flavour of muscle and hepatopancreas, slightly enhanced gonad and the overall flavour of S. paramamosain before overwintering was better than that after overwintering.  相似文献   

组合压气机中尾迹与势流同频/异频干涉的叠加特性     

赵奔  杨策  老大中  张卫正 《保鲜与加工》2013,12(4):477-485

为揭示多级压气机中上下游叶轮对中间叶片叠加气动影响特性,阐述不同叠加干涉情况下下游叶轮进气角度变化,采用数值方法模拟了一级轴流和一级离心组成的组合压气机非定常流场。详细讨论了上游动叶尾迹和下游动叶势流对中间导流叶栅段气流非定常流动的异频和同频叠加干涉特性,依据计算结果,直观地展示了静叶通道中两种干涉间相互激励和抑制作用的位置和时间,与数学公式的推导结果相互印证。研究结果表明:当上下游动叶对中间静叶段异频干涉时,干涉的激励、抑制区域的轴向位置随时间发生变化;当上下游动叶对中间静叶干涉频率相同时,干涉的相互激励、抑制区域的轴向位置不随时间发生变化,但干涉的激励、抑制区域的轴向位置受时序位置影响。另外,上游动叶尾迹与下游离心叶轮势流的不同叠加情况,决定着下游离心叶轮进口相对气流角的大小及波动幅值。   相似文献   

秸秆还田下土壤孔隙演化及其对溶质穿透特征的影响机理分析     

段正宇  朱成立  车子刚  嵇洪波  王策  陈晓安 《农业机械学报》2024,55(4):312-326

为揭示秸秆粉碎还田后,不同腐解进程下土壤孔隙演化及其对水分和溶质穿透特征的影响机理,设置不同秸秆还田量（0、5、10、15t/hm2）和还田时间（0、30、60d）处理,采用CT断层扫描技术,视觉量化了土壤孔隙结构特征演变,并基于溶质穿透试验,分析了水分-溶质迁移优先流规律。结果表明,秸秆还田引起土壤孔隙/喉道特征变化,抑制水分-溶质迁移过程,田间持水率和土壤含水率上升,溶质穿透变慢,优先流现象减少,土壤水肥有效持留;随秸秆腐解至60d,孔隙/喉道特征改变,优先流开始发育,但土壤水肥持留能力增强。秸秆还田5、10、15t/hm2初期,和CK组相比大孔隙体积占比分别减少7%、14%、50%,连通孔隙减少11%、39%、66%,表层含水率增加1%、3%、6%。腐解60d后,和0d相比大孔隙体积占比分别增加331%、200%、357%,连通孔隙增加33%、84%、195%,表层含水率增加6%、5%、5%,完全穿透试样所需溶质减少55%、76%、67%。基于Green-Ampt模型和指数衰减模型估算了不同秸秆初始投入量在不同腐解时间下的导水特征,发现饱和导水率在秸秆还田后减小,且随秸秆腐解增大。研究可为控制大孔隙流和无效灌溉提供依据,进一步为秸秆科学还田提供实践指导。  相似文献   

基于GF-1卫星遥感的河套灌区土壤含水率反演模型研究     

姚一飞  王爽  张珺锐  黄小鱼  陈策  张智韬 《农业机械学报》2022,53(9):239-251

为探究植被覆盖条件下GF-1卫星反演农田土壤含水率的可行性,以河套灌区解放闸灌域沙壕渠为研究区,采用GF-1卫星遥感影像作为数据源,通过全子集筛选法确定不同土壤深度下光谱指数的最优自变量组合,并分别采用多元线性回归(MLR)、BP神经网络(BPNN)、支持向量机(SVM)3种算法,构建不同深度下土壤含水率反演模型。结果表明,全子集筛选后模型反演精度有较大提升,且过拟合现象减弱;植被覆盖条件下各深度土壤含水率敏感程度从大到小依次为0~40cm、0~60cm、20~40cm、0~20cm、40~60cm;植被覆盖条件下各模型对土壤含水率反演能力由强到弱依次为BPNN、SVM、MLR;筛选后BPNN在深度0~40cm下的建模集和验证集R2adj均能达到0.50以上,RMSE在0.02%以内。研究结果可为植被覆盖条件下利用GF-1卫星监测农田土壤含水率提供参考。  相似文献   

湖北三峡库区晚熟脐橙不同海拔果实品质变化及枯水防控技术研究   总被引：1，自引：0，他引：1  

吴黎明  何利刚  王志静  宋放  王策  蒋迎春  刘继红  彭抒昂  鲍江峰  吴述勇  廖胜才  向进 《中国南方果树》2021,(1):18-24

以湖北三峡库区秭归地区不同海拔伦晚脐橙(Lane Late navel orange)果实为试验材料,探讨了湖北三峡库区晚熟脐橙果实枯水防控栽培技术,进行了晚熟脐橙种植区域布局研究.结果表明,在湖北三峡库区,长江南面晚熟脐橙适宜区域化种植在海拔360 m以下,长江北面在海拔350 m以下.在适宜范围外,随海拔升高,晚熟...  相似文献   

洋葱紫斑病病原菌鉴定及生物学特性     

王勇  周雪梅  盛洁  宋策  陈龙  陈典 《北方园艺》2016,(23):111-116

以黑龙江省3个地区洋葱紫斑病植株为试材,采用组织分离法分离洋葱紫斑病病原菌,对获得菌株进行致病性测定、形态学鉴定以及16srDNA ITS序列分析,并研究其生物学特性。结果表明:该致病菌为葱链格孢菌(Alternaria porri(Ell.)Cifferri),该菌株在以葡萄糖为碳源时产孢量最高,但菌丝生长量最低;在以氯化铵为氮源时菌丝生长量和产孢量都达到最高。32℃,pH 7,光照条件为12h光照/12h黑暗交替培养菌丝生长量最高;24℃,pH 8,连续黑暗条件下产孢量最高。  相似文献   

月季杂交后代花色遗传特性初探   总被引：1，自引：0，他引：1  

李晓丽  庄得凤  马策  马丹  李振涛 《北方园艺》2017,(14):96-98

以红、粉、白3种花色21个"茶香"月季品种为亲本材料,研究了不同花色组合后代的花色表现,总结花色遗传趋势,以期为月季杂交育种亲本花色的选择和选配提供参考。结果表明:红色与红色、红色与粉色、粉色与红色、粉色与粉色月季品种的杂交后代花色几乎是红色系和粉色系;白色与红色、粉色月季品种杂交,后代除红色系和粉色系外,还出现其它花色。  相似文献   

萝卜抗芜菁花叶病毒的研究现状     

刘根新  戴澈  许园园  苏小俊 《长江蔬菜》2016,(8):31-34

芜菁花叶病毒(TuMV)寄主范围宽广且对十字花科作物为害严重,从TuMV寄主范围与病原检测、发病症状、株系划分、遗传规律与抗性资源挖掘等方面简述了现阶段萝卜TuMV的研究进展,以期为萝卜等十字花科作物抗TuMV育种提供参考依据。  相似文献