Nutrient cycling and biomass flows in a low-quality forest stand improvement system in the Lesser Khingan Range of China     

Jinzhuo Wu  Linlin Kong  Xibin Dong 《Journal of Sustainable Forestry》2018,37(6):555-573

The material flow and bulk internal flow analyses were used to establish a material accumulation and cycling model for a low-quality forest stand improvement system and a series of processes were considered. The model was applied in a one-hectare low-quality forest plot in the Lesser Khingan Range of China. Results showed that during 1997–2007, the stands absorbed 270.19 kg of N, 74.28 kg of P, and 124.39 kg of K from soils, 51.82 kg of N and 2.38 kg of P were directly absorbed by foliage, and 16.25 kg of K was released to soils by eluviation. Until 2007, the accumulated nutrients in the stands included 236.91 kg of N, 65.28 kg of P, and 108.55 kg of K. When horizontal strip clearcutting was applied in 2007, 50% accumulated nutrients in the stands were shifted due to harvesting operations, and 212.74 kg of N, 26.97 kg of P, and 98.88 kg of K were accumulated in soils, declining by 9.47% for N, 3.68% for P, and 17.60% for K, respectively, compared with year 1997. 94.61 t per hectare of biomass was generated, of which the biomass in stands accounted for 87.36%. The felled tree biomass was 36.89 t per hectare, of which 84.90% and 10.03% of biomass were utilized in terms of logs and other means, and the rest was left on site.  相似文献   

Study on Anti-viral Effect of Rhubarb on Porcine Epidemic Diarrhea Virus in vitro     

CHEN Tian-tian  CHENG Fu-liang  ZHANG Jian-mei  NIE Zhao-jing  FANG Dong  FAN Mei-na  LI Fu-hui  CHENG He-gang 《中国畜牧兽医》2015,42(9):2474-2480

The inhibitory effects of rhubarb on cell lesion, which was caused by porcine epidemic diarrhea virus (PEDV), and its mechanism had been studied in this research.The maximum safe concentration of rhubarb solution applied to Vero cells was determined through morphological observation, and then the PEDV infected Vero cell model in vitro was established, by which the inhibitory effect of rhubarb on virus was studied.The experimental method had also been established based on this cell model.The result showed that the maximum safe concentration was 3.28 mg/mL.Both morphological observation and MTT assay were indicated that rhubarb could not only block the attachment of the virus to Vero cell and inhibit the synthesis and reproduction of the virus, but also could directly inactivate the virus.This research showed that rhubarb had an inhibitory effect on PEDV, and provided a theoretical basis for the prevention and treatment of clinical porcine epidemic diarrhea.  相似文献   

Expression and ontogeny of growth hormone (Gh) in the protogynous hermaphroditic ricefield eel (Monopterus albus)     

Dong Chen  Jiang Liu  Wanping Chen  Shuxia Shi  Weimin Zhang  Lihong Zhang 《Fish physiology and biochemistry》2015,41(6):1515-1525

  相似文献   

两种不同包装材料对扒鸡产品品质的影响     

董兰坤  曹倩倩  刘月英 《农业工程》2016,6(6):43-45

为研究两种不同包装材料对扒鸡产品品质的影响，分别对扒鸡贮存不同时间的微生物指标、质量损失进行检测分析，并进行感官评价。结果表明，不同包装材质对高温灭菌后扒鸡的微生物指标影响不大；包装B的氧气及水蒸气透过量明显低于包装A，并且在保护扒鸡色泽和香气、延缓脂肪氧化方面明显优于包装A。因此，高阻隔包装材料能够提高扒鸡的产品品质，延长保质期。   相似文献   

苹果属无融合生殖SERKs基因家族的克隆和表达分析     

张丽杰  郭苏漫  董文轩 《分子植物育种》2015,(5)

本研究利用同源克隆法以苹果属平邑甜茶和杂种后代叶片为试验材料,克隆得到4个SERK基因家族片段,并分析了SERKs家族基因在平邑甜茶和杂种后代不同器官和组织中的表达情况。研究结果表明:分离获得的4个SERK基因家族片段的氨基酸序列与模式植物拟南芥、烟草等植物的同源性均在84%以上,同时与其他物种的氨基酸序列进行Blast比对都具有较高的同源性;RT-PCR定量分析结果表明SERK1、SERK2、SERK3、SERK4基因主要在生殖器官中表达。因此,推测SERKs基因在平邑甜茶和杂种后代生殖发育过程中起着重要的调控作用。本研究结果为进一步揭示无融合生殖的发生机理奠定了基础。  相似文献   

基于WSN的集中通风式分娩猪舍环境参数时空分布特性   总被引：1，自引：1，他引：0  

曾志雄  余乔东  易子骐  吕恩利  董冰 《农业工程学报》2020,36(12):204-211

为研究集中通风式分娩猪舍环境参数的时空分布特性,以云南省某规模化种猪场为试验对象,利用无线多源多点远程监测系统(Wireless Sensor Network, WSN),对地沟管道进风、中央排风式分娩母猪舍养殖环境开展了环境参数监测试验,并进行统计分析。试验结果表明,在试验期间内,分娩舍内不同时间段之间的温度(00:00-06:00、06:00-12:00、12:00-18:00以及18:00-00:00的平均温度分别为22.98、23.78、24.44和23.61℃)具有显著性差异(P0.05),相对湿度与温度随时间变化呈现负相关性,相对湿度的峰值点为82.31%,温度场分布均匀性比湿度场好,NH_3浓度分布均匀性比CO_2浓度差。NH3浓度在舍内能被有效的维持在低水平范围,各监测区域的浓度远小于指标值(20 mg/m~3),NH_3和CO_2会呈现出在边角积聚现象。温湿度指数较低,舍内平均温湿度指数(Temperature-humidity Index,THI)水平的峰值点为75.30,生猪出现热应激的概率较低。利用WSN系统,对集中通风式分娩舍环境参数进行多源多点远程监测,分析分娩舍环境参数时空分布特性,为分娩舍通风模式与环境调控策略优化设计提供参考。  相似文献   

脉动燃烧技术及其在林业中的应用     

汪东  刘键  陈青  蒋雪松  周宏平  许林云  茹煜 《世界林业研究》2020,33(5):47-52

脉动燃烧是指在一定声振条件下发生的一种周期性燃烧，其燃烧室内压力强度、气流速度、温度及热释放效率等参数随着时间呈周期性变化，是一种特殊的不稳定燃烧过程，具有燃烧效率高、燃料经济性好、运行环境友好等优点。研制基于脉动燃烧技术的林业作业装备对于提高林业生产效率、促进环保高效燃烧技术的发展具有重要意义。文中概述了脉动燃烧技术的工作原理、特点及发展现状，介绍了脉动燃烧技术在林业病虫害防治、木材干燥和土壤消毒中的应用，并在分析脉动燃烧技术的不足及其在林业作业应用中存在问题的基础上，提出脉动燃烧技术在林业作业应用中的发展方向。  相似文献   

Identification and expression analysis of 11 MADS-box genes in peach (Prunus persica var. nectarina ‘Luxing’)     

Hui-Feng Li  Qing-Long Dong  Gui-Xiang Li 《The Journal of Horticultural Science and Biotechnology》2018,93(3):232-243

MADS-box genes play a central role in the development of flowers in plants. In this study, 11 PpMADSs were isolated from ‘Luxing’ peach, and the expression levels were detected in different tissues and fruit development. Eleven PpMADSs, designated as PpMADS13, 14, 18, 23, 24, 25, 32, 33, 34, 35, and 39 were isolated. Phylogenetic analysis revealed that PpMADS13, 14, and 18 belonged to SVP, AGL15, and MIKC* group respectively; PpMADS23, 24, 25, and 39 were in the Mα group; PpMADS32, 33, 34, and 35 belonged to the Mγ group. Predictions from subcellular localization showed that 10 PpMADS were located in the nucleus. RT-PCR revealed that PpMADS13 was expressed in stems, leaves, and during fruit development (70d); PpMADS14 was expressed in sepals, stamens, petals, and during flower development; PpMADS18 was expressed in roots, stems, leaves, sepals, ovaries, stamens, petals, and during flower and fruit development; all MADS-box genes (expect for PpMADS33) in the Mα and Mγ group were expressed in roots, stems, leaves, sepals, ovaries, stamens, petals, and during flower development; few genes were expressed during fruit development. These results indicated that PpMADS may play a crucial regulatory role in vegetative growth and development processes of flowers and fruits in peaches.  相似文献   

PEG模拟干旱胁迫下3种鄂尔多斯常见植物萌发期抗旱性评价     

董旋  王明玖  罗冬 《内蒙古草业》2015,(1):34-39

以聚乙二醇溶液(PEG-6000)为渗透介质模拟干旱条件,在12个水势梯度下,研究了干旱胁迫对木地肤、狭叶锦鸡儿和白沙蒿3种植物种子萌发的影响。结果表明,随着PEG-6000浓度的增大,3种植物的发芽率均呈现出明显的下降趋势;而较低浓度的PEG溶液可以对种子萌发产生促进和"刺激"的效果,加快种子萌发的速度,刺激初生根的生长,从而对发芽指数和萌发抗旱指数产生一定的影响。利用隶属函数综合评价3种植物在种子萌发期间的抗旱性,结果为木地肤>白沙蒿>狭叶锦鸡儿。  相似文献   

m6A甲基化在鸡肌肉生长发育中的表达研究     

丁浩  林月月  张涛  张闪闪  吴玉麟  段严军  巩用双  谢恺舟  王金玉  戴国俊  张跟喜 《中国畜牧兽医》2021,48(5):1525-1534

试验旨在研究RNA m6A修饰相关基因去甲基化酶Alk B同源蛋白5（Alk B homologue 5，ALKBH5）、去甲基化酶肥胖相关蛋白（fat mass and obesity-associated protein，FTO）、甲基转移酶样蛋白3（methyltransferase like 3，METTL3）、甲基转移酶样蛋白14（methyltransferase like 14，METTL14）和成肾细胞瘤1-结合蛋白（Wilms’tumor 1-associating protein，WTAP）在鸡骨骼肌发育过程中的表达，分析其与骨骼肌m6A甲基化水平的相关性。首先，利用实时荧光定量PCR技术检测m6A甲基化相关基因在金茅花鸡12（E12）、14（E14）、16（E16）、18（E18）胚龄和1日龄腿肌和胸肌组织中mRNA表达水平，以及其在鸡成肌细胞50%、100%增殖期和1、2、3、4、5 d分化期的mRNA表达水平；随后，利用m6A甲基化试剂盒检测金茅花鸡E12和1日龄腿肌和胸肌组织中m6A甲基化修饰水平，与m6A甲基化相关基因表达水平进行相关性分析。结果显示，m6A去甲基化基因ALKBH5和FTO mRNA表达水平在骨骼肌发育过程中显著上调（P<0.05），即在E12、E14低表达，E16、E18逐渐上调，1日龄达到最高。m6A甲基化写入基因METTL14、METTL3和WTAP mRNA表达水平在E12、E14、E16逐渐上升，E18下降，随后至1日龄表达量回升。在细胞增殖过程中，ALKBH5、FTO、METTL14、METTL3和WTAP基因表达均上调；在细胞分化过程中ALKBH5和FTO基因表达水平显著上调（P<0.05），在分化第5天达到最高。METTL14、METTL3和WTAP基因mRNA表达水平在细胞诱导分化的1、2、3、4 d表达量呈下降趋势，而在诱导分化的第5天有所回升。甲基化水平检测结果显示，腿肌和胸肌m6A甲基化水平变化趋势一致，均在胚胎发育过程中显著下降（P<0.05），至1日龄达到最低。相关性分析结果显示，鸡骨骼肌RNA m6A甲基化水平与m6A去甲基化修饰基因ALKBH5、FTO mRNA表达水平呈显著负相关（P<0.05）。综合以上试验结果，推测m6A甲基化修饰与鸡骨骼肌发育相关，而去甲基化基因ALKBH5、FTO可能通过调控RNA m6A甲基化水平，影响鸡骨骼肌发育。本研究结果为进一步研究m6A甲基化修饰调控鸡骨骼肌生长发育的功能和分子机制提供理论依据。  相似文献